PINEY RUN STREAM RESTORATION, CARROLL COUNTY, … · PINEY RUN STREAM RESTORATION, CARROLL COUNTY, MARYLAND: PROJECT SUMMARY AND DESIGN REPORT By: John B. Hutzell, Kathleen Cullen,

PINEY RUN STREAM RESTORATION, CARROLL COUNTY,

MARYLAND: PROJECT SUMMARY AND DESIGN REPORT

By: John B. Hutzell, Kathleen Cullen, and Richard R. Starr

Stream Habitat Assessment and Restoration Program

U.S. Fish and Wildlife Service

Chesapeake Bay Field Office

CBFO – S17 - 01

Annapolis, MD

March 2017

Piney Run Stream Restoration: Project Summary and Design Report

U. S. Fish and Wildlife Service March 2017

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TABLE OF CONTENTS

I. INTRODUCTION.................................................................................................................1

II. SITE SELECTION ...............................................................................................................1

III. PROJECT PROCESS METHODOLOGY ........................................................................2

A. Project Process ............................................................................................................................................. 2 B. Watershed Assessment ................................................................................................................................ 4 C. Reach Level Assessment ............................................................................................................................. 4

IV. PROGRAMMATIC / PROJECT GOALS .........................................................................5

V. WATERSHED ASSESSMENT ...........................................................................................5

A. Watershed Assessment Piney Run Mainstem .............................................................................................. 6 B. Watershed Assessment UT6 ........................................................................................................................ 8 C. Watershed Assessment UT6a ...................................................................................................................... 9

VI. REACH LEVEL ASSESSMENT ......................................................................................10

A. Function Based Rapid Assessment Table .................................................................................................. 10 1. Overall Existing Condition ............................................................................................................. 11 2. Level 2 – Hydraulics ....................................................................................................................... 12 3. Level 3 - Geomorphology ............................................................................................................... 12 4. Level 4 - Physicochemical .............................................................................................................. 13 5. Level 5 - Biology ............................................................................................................................ 14

B. Channel Evolution ..................................................................................................................................... 17 C. Level 3 Detailed Assessment Reaches ....................................................................................................... 17

1. Representative Reach - Piney Run .................................................................................................. 19 2. Representative Reach - UT6 Upper ................................................................................................ 21 3. Representative Reach - UT6 Middle ............................................................................................... 23 4. Representative Reach - UT6 Lower ................................................................................................ 25 5. Representative Reach - UT6a Lower .............................................................................................. 27 6. Biology ............................................................................................................................................ 29

VII. WETLAND ASSESSMENT ..............................................................................................30

VIII. DESIGN DEVELOPMENT ...............................................................................................32

A. Project Area Delineation ............................................................................................................................ 32 B. Constraints ................................................................................................................................................. 33 C. Restoration Potential .................................................................................................................................. 34 D. Design Objectives ...................................................................................................................................... 35 E. Design Alternatives Analysis ..................................................................................................................... 36

1. Potential Design Alternatives .......................................................................................................... 37 2. Design Alternatives Analysis .......................................................................................................... 38

a. Sediment Supply ..................................................................................................................................... 38 b. Stream Energy ......................................................................................................................................... 39 c. Floodplain Characteristics ....................................................................................................................... 39 d. Stream Channel Characteristics ............................................................................................................... 40

3. Preferred Plan .................................................................................................................................. 42 a. Potential Functional Uplift ...................................................................................................................... 42 b. Potential Adverse Impacts ....................................................................................................................... 42 c. Uncertainty and Risk ............................................................................................................................... 43 d. Implementation Costs .............................................................................................................................. 45



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F. Design Development ................................................................................................................................. 46 1. Design Criteria ................................................................................................................................ 47 2. Proposed Project Area Descriptions ................................................................................................ 47

a. Project Area 1 .......................................................................................................................................... 47 b. Project Area 2 .......................................................................................................................................... 48 c. Project Area 3 .......................................................................................................................................... 49 d. Project Area 4 .......................................................................................................................................... 50 e. Project Area 5 .......................................................................................................................................... 51 f. Project Area 6 .......................................................................................................................................... 52 g. Project Area 7 .......................................................................................................................................... 53 h. Project Area 8 .......................................................................................................................................... 54 i. Project Area 9 .......................................................................................................................................... 54 j. Project Area 10 ........................................................................................................................................ 55 k. Project Area 11 ........................................................................................................................................ 55 l. Project Area 12 ........................................................................................................................................ 56 m. Project Area 13 ........................................................................................................................................ 57 n. Project Area 14 ........................................................................................................................................ 57 o. Project Area 15 ........................................................................................................................................ 58 p. Project Area 16 ........................................................................................................................................ 59

3. In-stream Structures ........................................................................................................................ 59 a. Cross Vane .............................................................................................................................................. 59 b. J-Hook ..................................................................................................................................................... 60 c. Log Drop Structure .................................................................................................................................. 61 d. Toe Wood ................................................................................................................................................ 62 e. Oxbow/Vernal Pool Features .................................................................................................................. 63 f. Rock/Log Deflector ................................................................................................................................. 63 g. Constructed Riffle ................................................................................................................................... 64 h. Rock Step ................................................................................................................................................ 65 i. Step Pool Channel ................................................................................................................................... 65 j. Stacked Rock Wall .................................................................................................................................. 66 k. Grade Control Woody Riffle ................................................................................................................... 66 l. Ford Stream Crossing .............................................................................................................................. 67 m. Rock Toe ................................................................................................................................................. 67 n. Swale with Ditch Plugs ........................................................................................................................... 67

4. Hydrologic and Hydraulic Analyses ............................................................................................... 68 a. Bankfull Verification ............................................................................................................................... 68

i. Geomorphic Indicators ..................................................................................................................... 68 ii. Regional Relationships .................................................................................................................... 69 iii. Resistance Relationships ................................................................................................................ 69 iv. Bankfull Validation ........................................................................................................................ 73

b. Hydrologic and Hydraulic Assessment ................................................................................................... 73 c. Sediment Analysis ................................................................................................................................... 77

5. Vegetation Design ........................................................................................................................... 78

IX. IMPACTS TO EXISTING RESOURCES .......................................................................79



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LIST OF FIGURES Figure 1: Stream Function Pyramid (Harman et al., 2012) ........................................................................... 3 Figure 2: Stream Functions Pyramid Framework (Harman et al., 2012) ...................................................... 4 Figure 3: Piney Run Watershed and Subwatershed Delineation .................................................................. 6 Figure 4: Function Based Condition of reaches within the Piney Run project area ................................... 11 Figure 5: Representative Reaches with Level 3 Detailed Assessment........................................................ 19 Figure 6: Piney Run MBSS Sampling Site Locations ................................................................................ 29 Figure 7: Piney Run wetland locations identified by MDNR ..................................................................... 31 Figure 8: Project Reach Delineation ........................................................................................................... 32 Figure 9: Project Constraints ...................................................................................................................... 33 Figure 10: Channel formation tool with associated data from Piney Run plotted (Tweedy, K.L., 2008.). 41 Figure 11: Cross Vane in Plan View ........................................................................................................... 60 Figure 12: J-Hook Vane in Plan View ........................................................................................................ 61 Figure 13: Log Drop Structure .................................................................................................................... 62 Figure 14: Toe Wood .................................................................................................................................. 62 Figure 15: Oxbow Creation ........................................................................................................................ 63 Figure 16: Rock Deflector in Plan View ..................................................................................................... 64 Figure 17: Constructed Riffle in Plan View ................................................................................................ 64 Figure 18: Rock Step in Plan View ............................................................................................................. 65 Figure 19: Step Pool Channel in Plan View ............................................................................................... 65 Figure 20: Stacked Rock Wall in Plan View .............................................................................................. 66 Figure 21: Grade Control Woody Riffle in Plan View ............................................................................... 66 Figure 22: Ford Stream Crossing Structure ................................................................................................ 67 Figure 23: Rock Toe Structure .................................................................................................................... 67 Figure 24: Swale with Ditch Plugs in Plan View ........................................................................................ 68 Figure 25: Typical Bankfull Indicators (McCandless, 2003) ...................................................................... 69

LIST OF TABLES Table 1: Piney Run Function Based-Assessment Ratings which include functioning (F), functioning-at-

risk (FAR), and not-functioning (NF). FAR/F indicates transition from functioning-at-risk to functioning

and FAR/NF indicates transition from functioning-at-risk to not functioning. .......................................... 16 Table 2: Piney Run Level 3 Detailed Assessment Reach Distribution ....................................................... 18 Table 3: Piney Run Main Function-based Assessment Table ..................................................................... 20 Table 4: Piney Run Main Channel Evolution Rating.................................................................................. 21 Table 5: UT6 Upper Function-based Assessment Table ............................................................................. 22 Table 6: UT6 Upper Channel Evolution Rating ......................................................................................... 22 Table 7: UT6 Middle Function-based Assessment Table ........................................................................... 24 Table 8: UT6 Middle Channel Evolution Rating ........................................................................................ 25 Table 9: UT6 Lower Function-based Assessment Table ............................................................................ 26 Table 10: UT6 Lower Channel Evolution Rating ....................................................................................... 27 Table 11: UT6a Lower Function-based Assessment Table ........................................................................ 28 Table 12: UT6a Lower Channel Evolution Rating ..................................................................................... 28 Table 13: Piney Run Indices of Biotic Integrity ......................................................................................... 30 Table 14: Piney Run Project Areas 1, 2, 8, 10 - 13 and 16 - Design Objectives ........................................ 35 Table 15: Piney Run Project Areas 3 -7, 9, 14 and 15 - Design Objectives ............................................... 36 Table 16: Design and Regional Curve Bankfull Characteristics ................................................................ 73 Table 17: HEC-RAS Model Results ........................................................................................................... 76 Table 18: Sediment Transport Capacity for Representative Reaches ......................................................... 78 Table 19: Table of Potential Impacts to Existing Resources ...................................................................... 81



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APPENDICES Appendix A. Assessment and Design Review Checklists

Appendix B. Watershed Assessment

Appendix C. Level 3 Representative Reaches Data

Appendix D. DNR MBSS Biology Report

Appendix E. Wetland Assessment

Appendix F. Soil Trench Data

Appendix G. Project Reach Specific Design Criteria

Appendix H. Implementation Costs

Appendix I. Velocity Calculations

Appendix J. HEC-RAS: Existing and Proposed

Appendix K. Planting Plan

Appendix L. Impacts to Existing Resources



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I. INTRODUCTION

Maryland Department of Natural Resources (MDNR), Western Maryland Resource Conservation

and Development Council (RC&D) and the U.S. Fish and Wildlife Service (Service) -

Chesapeake Bay Field Office are involved in a collaborative effort to restore stream functions on

a large portion of Piney Run and its tributaries, located in Carroll County, Maryland. This project

is being done to address Total Maximum Daily Load (TMDL) targets put in place by the state of

Maryland and creating suitable habitat for Service trust species.

Piney Run is located in the Chesapeake Bay watershed in Carroll County, Maryland. It flows

southeast 5.5 miles from its source near Salem Bottom Road in Westminster, Maryland before

entering Piney Run Reservoir. The reservoir is approximately 300 acres and was built in 1967 to

serve as flood attenuation and as recreational water to the public. Piney Run exits the reservoir

via drop inlet structure and becomes a tail water stream controlled by the reservoir outfall. It then

flows for another 4.0 miles through the proposed 1,440 acre project area to its confluence with

the Patapsco River, which ultimately enters the Chesapeake Bay. The Piney Run watershed has

been hampered by poor agriculture practices as well as suburban development which has led to

extensive erosion and loss of aquatic habitat. The project area lies within a catchment that is

primarily mixed residential / agriculture land use with approximately 15 percent impervious

surface and 20 percent forested.

This report documents the findings of the function-based watershed assessment, function-based

reach-scale assessment and design development process used by the Service to develop the

restoration plan for the Piney Run Stream Restoration.

II. SITE SELECTION

MDNR approached the Service about the possibility of a large-scale stream restoration project

that would take place entirely on State owned property. MDNR had identified the site as a

priority for TMDL reduction, since changes could be made on a watershed scale in some of the

tributaries to Piney Run. The project site also aligned with Service priorities of improving habitat

for certain Federal Trust species. The Service conducted a rapid assessment on approximately 9

miles of stream within the project area to determine the restoration potential. Restoration

potential is the highest level of restoration or functional lift that can be achieved given the site

constraints and health of the watershed. Many reaches throughout the proposed project area have

been impacted by agriculture practices, which have led to unstable stream banks, disconnected

floodplains, poor bedform diversity, and little to no riparian vegetation or buffer. However, the

Service and MDNR felt that many of these functions could be restored, providing benefits for

habitat, as well as water quality.

Given the restoration potential, the Service felt that the proposed site is an excellent candidate for

stream restoration.




III. PROJECT PROCESS METHODOLOGY

A. PROJECT PROCESS

The Service used the “Function-based Stream Restoration Project Process Guidelines” (Starr et

al., 2016) in developing the most appropriate design approach for the proposed project. The

document guides users through the stream restoration process from developing well-articulated

goals and objectives, selecting watershed and reach-level assessment parameters and

measurement methods, conducting design alternatives analysis, developing restoration designs,

and establishing quantifiable and measurable monitoring performance standards. The goal of the

guidelines is to assist permit applicants in selecting and implementing the best project restoration

solution based on watershed health, stressors, constraints, reach-level conditions, restoration

potential, goals and objectives, and other regulatory requirements. The Function-based Stream

Restoration Project Process is comprised of nine sequential steps that create a transparent process

which directly links programmatic goals with design elements to support stream functions. Each

step builds upon the previous step and at each step, programmatic goals and design goals and

objectives are re-evaluated to ensure they can still be achieved.

The SFPF project process consists of the following steps:

Programmatic/Project Goals – Documents what is driving the project and why the project is

being proposed.

Watershed Assessment – Determines the health of the watershed and its influence on the proposed

project area.

Reach-Scale Function-based Assessment – Establishes the existing function-based condition,

determines stressors, identifies constraints, and determines channel functional evolution.

Restoration Potential – Determines the highest level of restoration that can be achieved given the

watershed conditions, function-based assessment results, stressors, and constraints. Also, it is at

this point that the actual amount of potential functional lift will be determined.

Design Objectives – Establishes design objectives based on the project goals, results of the

watershed and reach-scale function-based assessment, constraints, and restoration potential.

Design objectives define how the project is going to be completed.

Design Alternatives Analysis – Determines the restoration design approach that best meets the

project goals, objectives, and restoration potential of the site. The focus is on how a design

approach can change stream functions.

Design Development – Documents the design development process, ensures project feasibility,

determines project implementation costs, and produces a constructible design set along with

specifications and materials.

Monitoring Plan – Determines if the quantifiable project objectives are achieved and that existing

functioning parameters remain functioning.




The Function-based Stream Restoration Project Process Guidelines were developed following “A

Function-Based Framework for Stream Assessment and Restoration Projects” (Harman et al.,

2012). This document is based on the premise of a hierarchal relationship of stream functions

where lower-level functions support higher-level functions and that they are all influenced by

local geology and climate, which underlies the Pyramid (Figure 1 ). The Pyramid is a broad-level

view of stream functions and consists of five functional categories that evaluate stream functions.

Each category has a functional statement that describes its primary function. The framework that

supports the Pyramid, commonly referred to as the Stream Functions Pyramid Framework

(SFPF) is a “drilling down” approach that provides more detailed forms of analysis and

quantification of stream functions (Figure 2). The function-based assessment parameters describe

and support the functional statements within each functional category. The “measurement

methods” are specific tools, equations, assessment methods, etc. that are used to quantify the

function-based parameter.

Figure 1: Stream Function Pyramid (Harman et al., 2012)




Figure 2: Stream Functions Pyramid Framework (Harman et al., 2012)

B. WATERSHED ASSESSMENT

The purpose of the watershed assessment is to determine the influence of the watershed health on

the proposed project area. Specifically, watershed characteristics are evaluated to document

hydrology (i.e., flow regime), sediment supply (i.e., sources and amount), water quality (i.e.,

types and sources) and biology (i.e., locations and health). By understanding watershed

conditions, it can be determined if programmatic goals are achievable, as well as the restoration

potential of the project reach.

The watershed assessment involved two levels of assessment: stream-based assessment and land-

based assessment. The stream-based assessment involved a visual assessment of stream

character and stability condition upstream and downstream of the project area. The fluvial

geomorphic conditions observed included channel dimensions, pattern, profile, substrate

material, vertical and lateral stability, sediment supply potential, Rosgen stream type, and

channel evolution. The land-based assessment analyzed land use/land cover patterns, soils,

geology, hydrology, valley type, existing water quality and biological data, and watershed

development.

C. REACH LEVEL ASSESSMENT

The purpose of the reach level function-based assessment is to establish the existing functional

condition, determine stressors, and identify constraints at the proposed project site. The Service

conducted a rapid assessment of all stream reaches within the Piney Run project area and

Broad-Level View (Stream Functions Pyramid)

Function-Based Parameters

Measurement Methods Performance Standards

Functional Categories

Functional Statements

Describes/Supports

Functional Statement

Quantifies Function-Based Parameter Functioning

Functioning-At-Risk

Not Functioning




detailed function-based assessment at reaches that were representative of the function-based

conditions determined from the rapid assessment. The rapid assessment used the Function-based

Rapid Stream Assessment Protocol (Starr et al., 2015) and the detailed assessment used the

Rosgen Level 3 assessment method. Critical functions on every level of the pyramid were

assessed so that potential changes in functions could be evaluated for each proposed design

alternative. Additionally, critical functions supporting the project goals were assessed.

The following assessment parameters, by pyramid level, were evaluated:

Level 1 - Hydrology – concentrated flows, land use changes, and flashiness (flow regime)

Level 2 - Hydraulics – floodplain connectivity and floodplain drainage

Level 3 - Geomorphology – lateral stability and riparian vegetation

Level 4 - Physicochemical – overall water quality

Level 5 - Biology – macroinvertebrate communities and fish communities

Each assessment parameter had at least one measurement method to quantify the existing

function-based condition. Then, each measurement method value was rated as either functioning

(F), functioning-at-risk (FAR), or not functioning (NF) based on set performance standards.

To simplify plan review for these agencies, the Service has prepared the Function-based Stream

Restoration Project Process Review Checklist (Appendix A – Assessment and Design Review

Checklists).

IV. PROGRAMMATIC / PROJECT GOALS

The programmatic goals of the Piney Run stream restoration project differ among the main

agencies involved with the restoration. The funds for the project were provided by the MDNR,

whose goal is to focus funds on the most cost-effective, innovative approaches within an

efficient and logical location to improve the health of Maryland watershed lands, streams and

non-tidal rivers, as well as to reduce harmful TMDL. The Service’s goals are to create riparian

habitat for Eastern Wood-Peewee, Red-Shoulder Hawk and Acadian Flycatcher; to create

wetland habitat for Spotted Salamander, Gray Tree Frog and Northern Green Frog; and to

improve and preserve downstream habitat for American Eel and other aquatic species through

stream restoration.

The successful completion of the Piney Run stream restoration project will satisfy strategic

objectives put in place by the President Obama’s Chesapeake Bay Initiative, as well as the

Service’s strategic plan for trust species.

V. WATERSHED ASSESSMENT

There are three distinct watersheds that account for most of the water resources found within the

project limits of the Piney Run stream restoration (Figure 3). These watersheds represent the

contributing drainage areas to the main stem of Piney Run, Unnamed Tributary 6, and Unnamed




Tributary 6a. The Service identified and analyzed each of these watersheds. This section

includes a summary of each of the watersheds however, detailed watershed data can be found in

Appendix B.

Figure 3: Piney Run Watershed and Subwatershed Delineation

A. WATERSHED ASSESSMENT PINEY RUN MAINSTEM

The watershed drainage area is 15.2 sq mi (Figure 3) and lies within the piedmont physiographic

region of Maryland. What is unique about the main stem of Piney Run within the project area is

that a large recreational and water supply reservoir controls the discharges and sediments from

higher in the watershed. Understanding this condition is important because channel dimensions

are developed based on stream flows. If stream flows are over estimated, then there is a potential

for channel design dimensions to be oversized, which could lead to stream instability problems.




The Piney Run watershed has a flow regime typical of a rural hydrograph, and it is not

considered to be a “flashy” system. The 298-acre Piney Run Reservoir, found upstream of the

project site, has a large influence on the hydraulics of the watershed through its capacity and

controlled discharge. The watershed is approximately 45 percent agricultural, 25 percent

forested, 26 percent development (e.g., residential and commercial), and 15 percent

imperviousness. The shape of the basin is relatively narrow and long and has a slope of

approximately 6.9 percent. The predominant soils are considered moderate to well drained.

Given these watershed characteristics, the watershed flow regime would be considered just on

the edge of non-flashy. The percent of agricultural and imperviousness is just high enough to

start influencing precipitation runoff rates. However, the reservoir does serve as an attenuation

feature which lengthens the hydrograph and reduces the more harmful peak flows. Thus, the

proposed project area has more of a non-flashy flow regime but would likely be considered

flashy if the reservoir was not in place.

Sediment supply being delivered to the project area from the watershed is low to moderate.

While agricultural use represents approximately 45 percent of the watershed, the location of most

agriculture is upstream of the Piney Run Reservoir, limiting its impact. However, prior land use

changes are causing stream bank erosion directly upstream of the project area and, as a result,

increases in sediment supply. Therefore, the project area must be designed in such a way that it

addresses the sediment supply. The design could either transport the sediment, capture the

sediment, or some combination of both. How the sediment will be handled will be addressed

during the design alternatives analysis later in the report.

A 2006 wetland restoration prioritization report completed by MDE provided water quality

information for Piney Run Reservoir and Piney Run. Piney Run and all its tributaries are

considered Use III, natural trout waters. Above Slacks Road, Piney and its tributaries are listed as

Use III-P, natural trout waters and public drinking supply. The 303(b) report of the South Branch

Patapsco watershed noted that Piney Run was unable to support all its designated uses due to

nutrients, low dissolved oxygen, and aquatic plants (MDE, 2006). Piney Run is listed on the

303(b) report as having impaired water quality, due to poor biological community. The MDE

report summarized a water quality analysis for eutrophication in the reservoir, noting that water

quality was not impaired by nutrients (according to use designation requirements), but was

borderline mesotrophic and eutrophic.

Landscape connectivity of the project area plays a role on the ability of a stream restoration

project to result in biological uplift from two perspectives. The first is the stability condition of

upstream reaches. If upstream reaches are stable, then the amount of sediment being delivered to

the site would mostly likely not have adverse impacts. Second, if the upstream, as well as the

downstream reaches, are stable and healthy (meaning they support biological life), then they can

be a source of macroinvertebrates and fish to recolonize the project area. The conditions of

stream reaches upstream and downstream of the project area are fair, and can provide some

source for biological recolonization of the project area.




B. WATERSHED ASSESSMENT UT6


region of Maryland. The drainage area associated with UT6 is the most impacted by

development and imperviousness in the entire project area.

The Piney Run watershed has a flow regime more typical of an urban hydrograph, and is

considered to be a “flashy” system. The watershed is approximately 67 percent developed, 15

percent forested, 15 percent agriculture and 34 percent imperviousness. Contrary to the Piney

Run watershed, the shape of this basin is nearly as wide as it is long and has a slope of

approximately 7.2 percent. The predominant soils are considered moderate to well drained. The

percent of agricultural and imperviousness is high enough to start influencing precipitation

runoff rates. However, the Carroll County government has begun implementing a number of

stormwater retrofits which have been able to extend the hydrograph and reduce harmful peak

flows. The County plans to continue retrofits in the area.

Sediment supply being delivered to the project area from the watershed is moderate to high. The

Service conducted a brief sediment analysis at three locations upstream of the UT6 project area

and noted moderate to high erosion rates at two of the three sites. Prior land use changes coupled

with development and impervious surfaces are causing stream bank erosion directly upstream of

the project area and, as a result, an increase in sediment supply. Therefore, the project area must

be designed in such a way that it addresses the sediment supply. The design could either

transport the sediment, capture the sediment, or some combination of both. How the sediment

will be handled will be addressed during the design alternatives analysis later in the report.

The water quality being delivered to the project area is fair. While no physical data were

collected, watershed variables such as land use, soils and point and non-point discharges can be

used to predict water quality conditions. The project area watershed is primarily developed, has

highly erodible soils, point source discharges, and a flashy flow regime. Under these conditions

there will be an excessive sediment supply and frequent flooding and drying events which can

cause rapid and adverse changes in pH, dissolved oxygen, conductivity, nitrogen, phosphorus,

siltation levels, and concentrations of ions, toxins or pollutants (Williams, 1996) within the

reach.












C. WATERSHED ASSESSMENT UT6A


region of Maryland. Since UT6a is a sub-watershed of UT6, it is plagued by similar stressors.

The UT6a watershed has a flow regime more typical of an urban hydrograph, and is considered

to be a “flashy” system. The watershed is approximately 67 percent developed, 15 percent

forested, 15 percent agriculture and 38 percent imperviousness. Contrary to the Piney Run

watershed, the shape of this basin is nearly as wide as it is long and has a slope of approximately

8.0 percent. The predominant soils are considered moderate to well drained. The percent of

agricultural and imperviousness is high enough to start influencing precipitation runoff rates.

However, the Carroll County government has begun implementing a number of stormwater

retrofits which have been able to extend the hydrograph and reduce harmful peak flows. The

County plans to continue retrofits in the area.

Sediment supply being delivered to the project area from the watershed is moderate. The Service

conducted a brief sediment analysis at three locations upstream of the UT6a project area and

noted low to moderate erosion rates at two of the three sites. Prior land use changes coupled with

development and impervious surfaces are causing stream bank erosion directly upstream of the

project area and, as a result, increases in sediment supply. Therefore, the project area must be

designed in such a way that it addresses the sediment supply. The design could either transport

the sediment, capture the sediment, or some combination of both. How the sediment will be

handled will be addressed during the design alternatives analysis later in the report.

The water quality being delivered to the project area is fair. While no physical data were

collected, watershed variables such as land use, soils and point and non-point discharges can be

used to predict water quality conditions. The project area watershed is primarily developed, has

highly erodible soils, point source discharges and a flashy flow regime. Under these conditions

there will be an excessive sediment supply and frequent flooding and drying events which can

cause rapid and adverse changes in pH, dissolved oxygen, conductivity, nitrogen, phosphorus,

siltation levels, and concentrations of ions, toxins or pollutants (Williams, 1996) within the

reach.












VI. REACH LEVEL ASSESSMENT

A comprehensive function-based assessment was conducted in all tributaries within the project

site, as well as a BANCS survey to determine bank erosion rates. This information was compiled

and each reach was classified in terms of function. The findings allowed the reaches to be

categorized and helped define areas that could be surveyed in further detail to collect

representative geomorphic data.

While the initial assessment focused on the entire state-owned property, it was decided amongst

partners that the project should be parsed out into two design sections to better serve the

forecasted construction effort. These sections were then referred to Phase 1 and Phase 2. The

remainder of this report focuses on the Phase 1 design area which is the lower portion of Piney

Run watershed below Slacks Road.

A. FUNCTION BASED RAPID ASSESSMENT TABLE

The Service conducted a rapid stream assessment of all stream systems within the project using

the Function-based Rapid Stream Assessment Protocol (Starr et al, 2015), as described in the

Section III-Project Process Methodology.




Figure 4: Function Based Condition of reaches within the Piney Run project area

1. Overall Existing Condition

The overall function-based existing conditions of the Piney Run project include functioning (16

reaches), functioning-at-risk (29 reaches), and not functioning (6 reaches) conditions, as shown

in Figure 4 above and Table 1 below. Additionally, there were 22 reaches that have transitionary

conditions including functioning-at-risk to functioning and functioning-at-risk transitioning to

not functioning. Transitionary conditions describe whether reaches are naturally evolving to

either more or less stable conditions. There are 11 reaches that were characterized as undergoing

an overall transition to functioning conditions from functioning-at-risk. These reaches have had a

long enough time frame to adapt to the stress that was placed on the historic channel and have

established a floodplain, grade control and stable plan form to almost be fully stable. Eleven

other reaches were transitioning from functioning-at-risk to not functioning conditions. These




reaches are undergoing further degradation and are just beginning vertical downcutting and will

take significant time to reach stable conditions naturally.

Overall, the main stem of Piney Run and the unnamed tributaries below Slacks Road have been

significantly impacted by agricultural development in the watershed. Generally, the unnamed

tributaries in the headwaters of the watershed are in the best condition relative to the watershed.

The better overall condition can be linked to the existing forested environment that helps buffer

concentrated runoff, limited channel incision due to bedrock grade controls, and less stream

energy to cause incision due to lower energy gradients. Stream reaches in the middle and lower

portions of the watershed are in generally poorer conditions than the headwater reaches. These

reach conditions are adversely impacted because of their closer proximity to agricultural

development which has increased concentrated flows, and significantly reduced riparian

vegetation that resulted in rapid vertical and lateral stream degradation and adverse impacts to

quality and aquatic species. A description of existing function based conditions is described by

Pyramid Levels 2 through Level 5 below.

2. Level 2 – Hydraulics

Level 2 – Hydraulics is assessed by the streams connectivity to the floodplain. Floodplain

connectivity is measured by the bank height ratio and entrenchment ratio. The bank height ratio

provides a measurement of how quickly stream flows overtop their banks and inundate the

floodplain. The entrenchment ratio then describes the width of the floodplain available for flood

flows to spread out once stream flows have overtopped the banks. The mainstem of Piney Run is

characterized as functioning-at-risk for all assessed reaches. This means that the stream is on

average significantly incised and moderately entrenched, meaning that greater discharge

volumes, with higher associated flow velocities, are required to overtop the banks and inundate

the floodplain. In total, over half of the total length of the project (49 of the 74 assessment

reaches) across Piney Run and its tributaries are described as not functioning or functioning-at-

risk for floodplain connectivity. The remaining 25 assessed reaches had conditions that could be

characterized as functioning in terms of floodplain connectivity. These reaches can access

floodplain areas frequently with smaller discharge flows, and thereby decrease in-stream

discharge velocities which in turn reduces shear stress on banks. The more frequent inundation

of the floodplain also reduces sediment load and helps promote development of wetland

complexes.

3. Level 3 - Geomorphology

Level 3 – Geomorphology is assessed by lateral stability, bedform diversity, sediment transport,

riparian vegetation, and channel evolution. Lateral stability is a measurement of how quickly

banks are eroding and the total extent of bank erosion along the stream. Stabilization of bank

erosion is a primary goal in almost all stream restoration projects. The assessment of bedform

diversity measures variables such as pool-to-pool spacing, pool depth, and shelter for fish. These

measurement methods provide measures to determine if the physical environment required for

natural stream processes and aquatic life are present. Sediment transport then helps evaluate the

stability of the current channel form. Sediment transport stability for a stream determines if

aggradation and degradation forces within the stream reach are in a pseudo-equilibrium. Riparian




vegetation assesses the quantity and quality of vegetation along the stream banks, which help

promote beneficial stream functions and lateral stability. Finally, channel evolution synthesizes a

variety of assessment parameters to determine how the stream is adjusting to its new

environment and imposed conditions. Results from this section are described in detail in Section

VI.B–Channel Evolution. Reaches that are characterized as functioning have indicators of a

stable stream system including a lack of vertical or lateral adjustments, a developed and

vegetated floodplain, and appropriate floodplain drainage to limit concentrated flows.

Across the Piney Run mainstem and tributary reaches, only approximately one-third (23 of the

74 assessed reaches) of the Piney Run project had functioning conditions for lateral stability.

This means that 51 of the assessment reaches have either localized or widespread bank erosion

caused by the increased flow velocities and shear stresses as suggested in the hydrology and

hydraulics assessments. Bedform diversity is either characterized as functioning-at-risk or not

functioning in 55 of the assessment reaches. The increased stream energy and bank erosion

contribute to poor bedform diversity by straightening the channel and removing meander bends

where deep pools are located. While large woody debris or large rock can lead to the formation

of scour pools in straightened and incised channels, lack of these natural grade control structures

in areas of Piney Run prevents the establishment of natural scour pools to replace meander pools.

Sediment transport (vertical stability) is the next Geomorphology assessment parameter and

approximately one-third (29 of the 74 assessment reaches) of the Piney Run project is

characterized by functioning conditions. While there are areas of extensive bank erosion across

the Piney Run project, the increased flow velocities can transport the sediment through the

reaches and prevent widespread aggradation on the channel bed. Focusing on vertical stability,

channel beds in several reaches are controlled by bedrock to prevent extensive headcuts and

gentler downcutting of the channel bed. Riparian vegetation is the assessment parameter most

often characterized as not functioning, with 28 assessment reaches. Thirty-five assessment

reaches are characterized as functioning-at-risk and a small portion, only 11 assessment reaches,

are characterized as functioning. Encroachment into the natural stream corridor and riparian

buffer that helps manage and mitigate stormwater runoff is one of the common adverse impacts

to stream channels from nearby development. Channel evolution is the final assessment

parameter that combines several pieces of information and 23 of the assessment reaches were

characterized as functioning. The remaining 51 assessment reaches all show evidence of

undergoing some channel adjustments to reach a new stable state with the environment. For

Geomorphology overall, 17 of the 74 assessment reaches can be characterized as functioning, 50

assessment reaches functioning-at-risk, and 7 assessment reaches not functioning.

4. Level 4 - Physicochemical

Level 4 – Physiochemical is assessed by water quality appearance and nutrient levels. The rapid

assessment evaluates qualitative parameters including water clarity, oil sheens, films, and algal

growth. When present, these criteria are signs of untreated runoff entering the stream that can

impair water quality. Only one assessment reach, where flow was mostly a result of concentrated

stormwater runoff, was characterized as having not functioning water quality and nutrients.

Twenty-eight assessment reaches were then characterized to have functioning water quality

conditions while the rest of the 45 assessment reaches were characterized to be functioning-at-

risk. These water quality conditions for Piney Run and its tributaries in the project area are




typical for a stream that is impacted by increased runoff and a high sediment load. Efforts to

increase water quality must be focused on improvement to the watershed health and decreased

sediment and nutrient loading from untreated runoff.

5. Level 5 - Biology

Level 5 – Biology is assessed by the presence of macroinveterbrates and fish species in the

reach. The rapid assessment evaluates the presence of various species as abundant, rare, or

absent within the stream channel. Eleven assessment reaches were found to have abundant

populations of various species that allow biology to be characterized as functioning. Conversely,

16 of the assessment reaches had a lack of aquatic life that required the biology to be

characterized as not functioning. The presence of healthy populations in certain reaches in the

Piney Run project area suggest that with appropriate uplift to habitat and improvements to water

quality, natural recolonization is possible inside the project.

Stream

Segment

Stream

Reach

Assessment Parameter

Overall

Function-

Based

Condition

Level 2 -

Hydraulics Level 3 - Geomorphology

Level 4 –

Physico-

chemical

Level 5

-

Biology

Floodplain

Connectivity

Lateral

Stability

Bedform

Diversity

Sediment

Transport

(Vertical

Stability)

Channel

Evolution

Trend

Riparian

Vegetation

Overall

Geomorphology

Conditions

Water

Quality and

Nutrients

Presence

Piney

Run

1 FAR FAR FAR FAR FAR FAR FAR FAR FAR FAR

2 FAR/F FAR/F FAR F FAR NF FAR FAR FAR FAR/F

3 FAR

FAR/

NF FAR FAR FAR NF FAR FAR FAR FAR

4 FAR FAR F F FAR NF FAR FAR FAR FAR

5 FAR NF FAR FAR FAR NF FAR FAR FAR FAR/NF

6 FAR FAR FAR FAR FAR NF FAR FAR FAR FAR/F

7 FAR FAR FAR FAR FAR FAR FAR FAR FAR FAR/F

UT1

1 FAR FAR FAR FAR FAR NF FAR NF NF FAR/NF

2 WETLAND COMPLEX

3 FAR FAR FAR FAR NF FAR FAR FAR FAR FAR

4 NF FAR FAR FAR NF NF NF FAR FAR FAR/NF

UT1a 1 F F NF FAR F NF FAR FAR NF FAR/NF

UT2

1 F F FAR F F FAR FAR FAR NF FAR/F

2 FAR FAR FAR F FAR FAR FAR FAR NF FAR/F

3 FAR FAR NF FAR FAR NF FAR FAR NF FAR/F

4 WETLAND COMPLEX F

5 FAR FAR FAR FAR FAR NF FAR FAR NF FAR

6 F FAR F F F FAR F FAR NF F




7 FAR FAR FAR FAR FAR NF FAR FAR NF FAR

8 FAR NF FAR FAR FAR FAR FAR FAR FAR FAR

9 F F FAR F F FAR F FAR FAR F

10 FAR FAR FAR FAR FAR NF FAR FAR NF NF

UT2a 1

2

UT3

1 WETLAND COMPLEX

2 F F FAR F F NF FAR F FAR FAR

3 FAR FAR FAR FAR FAR NF FAR F FAR FAR/NF

UT3a 1 F F FAR FAR FAR FAR FAR FAR NF FAR/F

UT4

1 FAR FAR NF FAR FAR FAR FAR FAR FAR FAR

2 WETLAND COMPLEX

3 FAR FAR NF NF

FAR/N

F FAR FAR/NF FAR FAR FAR/NF

4 FAR FAR NF NF FAR FAR FAR FAR NF FAR/NF

5 WETLAND COMPLEX

UT5 1 FAR F FAR F F NF FAR FAR FAR FAR/F

UT6

1 F F F F F FAR F F F F

2 FAR FAR F F FAR FAR F F FAR FAR

3 FAR F F FAR FAR F FAR F FAR FAR

4 FAR FAR FAR FAR FAR F FAR F FAR FAR

5 NF NF NF FAR NF F NF F FAR NF

6 F F F F F F F F FAR F

7 F F F F F NF F F FAR F

8 FAR FAR FAR FAR FAR NF FAR FAR FAR FAR

9 NF NF FAR FAR NF FAR NF FAR FAR NF

10 FAR NF FAR FAR FAR NF FAR FAR F FAR/NF

11 FAR FAR FAR FAR FAR NF FAR/NF FAR/F

FAR/

F FAR/F

12 NF NF NF NF FAR NF NF FAR FAR FAR/NF

UT6a

1 F FAR FAR FAR FAR FAR FAR FAR FAR FAR

2 F FAR FAR FAR FAR FAR FAR FAR FAR FAR


4 NF FAR FAR FAR FAR FAR FAR FAR FAR FAR

5 FAR FAR FAR FAR FAR FAR FAR F FAR FAR






UT6a1 1 FAR FAR F FAR FAR FAR FAR F F FAR

UT6a2 1 FAR FAR F FAR FAR F FAR F FAR FAR

2 F FAR FAR F FAR FAR FAR F F F

UT6b

1 F F F F F FAR FAR FAR F F

2 F F FAR F FAR FAR F FAR NF F

3 FAR FAR FAR FAR FAR FAR FAR F

FAR/

F FAR

4 NF FAR NF NF NF FAR NF FAR F NF

UT6c

1 F F F F F FAR F F N/A F

2 NF NF NF NF NF NF NF FAR N/A NF

3 F F F F F NF FAR F N/A F

4 WETLAND COMPLEX

UT6e

1 NF NF FAR NF NF FAR FAR/NF FAR FAR NF

2 FAR NF FAR FAR FAR FAR FAR FAR FAR FAR/NF

3 F F F F F FAR F F F F

4 FAR FAR FAR FAR FAR FAR FAR F FAR FAR/NF

5 FAR FAR FAR F F NF FAR F FAR FAR

UT6e1

1 F F F F F NF F F NF F


3 F F F F FAR FAR FAR FAR NF FAR

4 FAR FAR FAR F F NF FAR FAR FAR FAR

UT6e1

a 1 FAR FAR FAR F F NF FAR FAR FAR FAR

UT6f 1 FAR FAR FAR FAR FAR FAR FAR F FAR FAR

UT6g 1 F F FAR F F F F F F F

UT8

1 F F F F F F F F F F

2 F F FAR F F F F F F FAR/F

3 F F F F F FAR F F NF FAR/F

4 WETLAND COMPLEX

5 WETLAND COMPLEX

6

REACH EXTREMELY SHORT THEREFORE INDIVIDUAL PARAMETERS NOT

ASSESSED F

UT8a 1 F F F F F F F F FAR F

UT9 1 F F F F F F F F F F

2 NF NF NF FAR FAR F NF F NF NF

Table 1: Piney Run Function Based-Assessment Ratings which include functioning (F), functioning-at-risk (FAR), and not-functioning (NF). FAR/F indicates transition from functioning-at-risk to functioning

and FAR/NF indicates transition from functioning-at-risk to not functioning.




B. CHANNEL EVOLUTION

Channel evolution can be used to characterize natural trends that will determine the future

stability of stream channels. Stable reaches are characterized as functioning in channel evolution

and have evolved to channel dimensions and plan form that maintain equilibrium conditions in

the new environment. This includes vertical and lateral stability from channels having formed a

new floodplain with meanders where possible. Overall, approximately one-third of the Piney

Run project area reaches (23 assessment reaches) have reached an evolutionary end-point and

will be stable with the new environmental conditions.

Assessment reaches that are characterized as functioning-at-risk for channel evolution are in the

mid-point of their evolutionary transition to adjust to new environmental conditions.

Approximately two-thirds of the Piney Run project (43 of the 74 assessment reaches) have

undergone vertical adjustments and channel degradation with the floodplain being fully

developed. These are an indicator of adjustments required for future channel stability in the new

environmental conditions. Further stability will then occur from bank stabilization that may take

decades or longer to fully establish. Development of riparian vegetation will help promote

stability of channel banks, plan, and profile. However, it will take a considerable time for these

reaches to adjust their plan form to reach stable conditions necessary to equilibrate with changes

to stream energy and sediment supply.

Finally, approximately one-tenth (8 assessment reaches) of the Piney Run reaches are

characterized for channel evolution as reaches that are not functioning or are transitioning from

functioning-at-risk to not functioning. This characterization describes reaches that are just

beginning downcutting and are undergoing significant lateral erosion in an attempt to adjust to

the new environmental conditions. The streams are beginning the evolution transition and will

take a considerable time to adjust their grade and plan form to reach the stable conditions

necessary to equilibrate with changes to stream energy and sediment supply.

C. LEVEL 3 DETAILED ASSESSMENT REACHES

Representative reaches (Figure 5) were identified within Phase 1 of the Piney Run restoration

area as reaches that could be used to develop existing geomorphic conditions and verify design

ratios for the majority of the restoration site. These reaches were selected by valley type, stream

type, function-based condition and restoration potential. The distribution of reaches that were

represented is shown below in Table 2.




Level 3 Detailed Assessment Reach Distribution

Detailed

Assessment

Reach

Represented Reach

Piney Run Piney Run Reaches 1 - 7

UT6 Upper UT6 Reaches 1 - 6, UT6e Reaches 1 - 5, UT6e1 Reaches 1 - 4

UT6 Middle UT6 Reaches 7 - 9

UT6 Lower UT6 Reaches 10 - 12

UT6a Lower UT6a Reaches 1 - 7, UT6a1 Reach 1, UT6a2 Reaches 1 - 2

Table 2: Piney Run Level 3 Detailed Assessment Reach Distribution

In addition to the Rapid Stream-Function Based Assessment (Davis, et al., 2014) and Bank

Erosion Hazard Index / Near-Bank Stress survey (Rosgen, D.L., 2009) conducted throughout the

project area, detailed geomorphic assessments were conducted in these “representative” locations

in accordance with Rosgen Level III procedures. Collecting detailed information from these

representative reaches allowed the design team to characterize existing conditions quantitatively

and gather data necessary for design development. The summary information for each of these

sites can be found below with detailed information available in Appendix C.




Figure 5: Representative Reaches with Level 3 Detailed Assessment

1. Representative Reach - Piney Run

The Service determined that the overall function-based condition of the main stem of Piney Run

is Functioning at Risk and is trending towards stability. It is perennial and classified as an

unstable Rosgen C4. The stream is slightly incised but not entrenched and therefore is somewhat

connected to its floodplain during larger than bankfull flood events. The floodplain is very broad

in relation to stream channel width with some concentrated flow paths from steep terrain nearby,

but is mostly sheet flow. Stream bank erosion is localized, mainly associated with outside

meander bends, and the channel exhibits indices of high levels of bank erosion and near bank

shear stress. The materials eroding from the stream banks are contributing to the sediment load




being delivered to the project areas downstream. The pools and riffles are well defined and the

pools depths are sufficiently able to promote good shelter for fish and macroinvertebrates. The

riparian vegetation is poor, and consists primarily of mixed pasture grasses and very few trees or

shrubs. Rooting depth of vegetation is shallow, which exacerbates bank erosion. The water

quality of the project area is fair and impaired mostly by temperature and stormwater runoff from

higher in the watershed. The water throughout the reach is clear and only cloudy after rain

events. Minimal woody debris or detritus was present throughout this reach.

Based on the Services Rapid Stream Function – Based Assessment, the Biology is fair since

there is presence of tolerant fish and macroinvertbrates. Table 3 shows the parameters collected

and function-based ratings given for this reach. More detailed biologic data from Piney Run can

also be found below, in Section VI.C.6-Biology.

Table 3: Piney Run Main Function-based Assessment Table

Piney Run Main is undergoing channel evolution from a Rosgen C4 stream type towards a

stable, functioning C4 stream. The stream is slightly incised likely due to previous degradation;

however it is no longer adjusting vertically. There are some areas of active lateral erosion that

Value Rating Overall by Level Overall Reach

Bank Height

Ratio1.2 FAR

Entrenchment

Ratio8.84 FAR

Floodplain DrainageFWS Rapid

Assessment Visual FAR

Riparain VegetationFWS Rapid


Dominant Bank

Erosion RateH/H FAR

Meander Width

Ratio1.3 - 3.3 FAR

Shelter for Fish Visual FAR

Pool-to-pool

Spacing1.0 - 3.4 FAR

Pool Depth

Variability2.2 - 2.5 F

Water Appearance

and Nutrients

FWS Rapid


DetritusFWS Rapid


Macro Species and

RichnessBIBI Poor NF

Fish Species and

RichnessFIBI Good F

FAR

2 - Hydraulics

Piney Run Main

Level and

CategoryParameter

Measurement

Method

Pre-Restoration Condition

Floodplain

ConnectivityFAR

3 -

GeomorphologyFAR

Lateral Stability

Bedform Diversity

4 -

PhysicochemicalFAR

5 - Biology FAR




will continue to occur until addressed. Because of these instabilities, the channel evolution rating

of the reach was considered to be functioning-at-risk, as shown in Table 4. It is important to

note however, that the current stable configuration is much smaller than it was historically. Since

the construction of the Piney Run reservoir upstream, the amount of unrestricted drainage to this

point has been reduced, allowing for a smaller channel configuration to exist. This is evidenced

by the fact that this smaller channel is beginning to form within the bounds of the larger channel

that once existed. Depositional features are present indicating the generation of a new floodplain

within the bounds of the old channel.

Table 4: Piney Run Main Channel Evolution Rating

2. Representative Reach - UT6 Upper

The Service determined that the overall function-based condition of UT6 Upper is Functioning

at Risk and is trending towards stability. It is perennial and classified as an unstable Rosgen B4c.

The stream is slightly incised but not entrenched and therefore, is connected to its floodplain

during bankfull and larger flood events. The floodplain is relatively narrow in relation to stream

channel width, with some concentrated flow paths from steep terrain nearby. Stream bank

erosion is localized and the channel exhibits indices of moderate bank erosion and near bank

shear stress. While minor, the materials eroding from the stream banks are contributing to the

sediment load being delivered to the project areas downstream. The pools and riffles are well

defined and the pools depths are sufficiently able to promote good shelter for fish and

macroinvertebrates. The riparian vegetation is moderate to good, and consists primarily of

mixed hardwood canopy trees with a thin understory. The water quality of the project area is fair

and impaired mostly by temperature and stormwater runoff for higher in the watershed. The

water throughout the reach is clear, and an abundance of detritus is present.


there is presence of tolerant macroinvertbrates. No fish were seen or identified in this particular

reach. Table 5 shows the parameters collected and function-based ratings given for this reach.

Piney Run Main - Function-based Assessment Summary and Channel Evolution

Reach Length (ft)

Rosgen

Stream

Type

Channel Evolution Reach Level Function-

based Rating

908 C4 Unstable C4 C4 FAR




Table 5: UT6 Upper Function-based Assessment Table

UT6 Upper is undergoing channel evolution from an unstable Rosgen B4c stream type towards a

stable B4c. The stream is slightly incised likely due to previous degradation, however it is no

longer adjusting vertically. This is evidenced by the exposed bedrock throughout the stream

reach that provides vertical grade control. There are some areas of active lateral erosion that will

continue to occur until addressed. Because of these instabilities, the channel evolution rating of

the reach was considered to be functioning-at-risk, as shown in Table 6.

Table 6: UT6 Upper Channel Evolution Rating


Bank Height

Ratio1.37 FAR

Entrenchment

Ratio1.82 FAR





Dominant Bank

Ersoion RateM/M FAR

Meander Width

Ration/a n/a

Shelter for Fish Visual F

Pool-to-pool

Spacing2.1 - 7.0 F

Pool Depth

Variability1.7 - 2.0 F

Water Appearance

and Nutrients

FWS Rapid

Assessment Visual F

DetritusFWS Rapid

Assessment Visual F

Presence Present F

Tolerance Moderate FAR

Fish Presence Absent NF

Lateral Stability

Bedform Diversity

4 -

PhysicochemicalF

UT6 Upper

Level and

CategoryParameter

Measurement

Method


5 - BiologyMacro

FAR

FAR

2 - Hydraulics

Floodplain

ConnectivityFAR

3 -

GeomorphologyF

UT6 Upper - Function-based Assessment Summary and Channel Evolution

Reach Length (ft)

Rosgen

Stream

Type


based Rating

402 B4c Unstable B4c B4c FAR




3. Representative Reach - UT6 Middle

The Service determined that the overall function-based condition of UT6 Middle is Functioning

at Risk and is trending towards further instability. It is perennial and classified as an unstable

Rosgen C4. The stream is moderately incised but not entrenched and therefore, is only

connected to its floodplain during greater than bankfull flood events. The floodplain is broad in

relation to stream channel width, with some concentrated flow paths from wetlands and

floodplain depressions nearby. Stream bank erosion is widespread and the channel exhibits

indices of high to very high bank erosion and near bank shear stress. The materials eroding from

the stream banks are contributing to the sediment load being delivered to the project areas

downstream. The pools and riffles are not well defined and the pools depths are less than

desirable for fish and macroinvertebrate habitat. The riparian vegetation is lacking, and consists

primarily of mixed pasture grasses with very few shrubs and/or trees for shading or soil stability.

The water quality of the project area is fair and impaired mostly by temperature and stormwater

runoff from higher in the watershed. The water throughout the reach is clear to cloudy, however

no detritus is present.

Based on the Services Rapid Stream Function – Based Assessment, the Biology is functioning-

at-risk since there is presence of tolerant fish and macroinvertbrates. Table 7 shows the

parameters collected and function-based ratings given for this reach.




Table 7: UT6 Middle Function-based Assessment Table

UT6 Middle is undergoing channel evolution from a Rosgen unstable C4 stream type towards an

intermediate F4 stream type, and ultimately a B4c channel. It is undergoing major changes and is

not stable in its current configuration. The ability of the stream to evolve back to some level of

quasi-equilibrium is unlikely to occur anytime in the near future without intervention. The

geomorphic functions are still undergoing significant adjustment. The stream still seems to be

adjusting vertically; however, lateral erosion is more prevalent throughout the reach and will

continue to occur until it is reconnected to a new stable floodplain. During this time, riparian

vegetation needs to establish and mature in order to assist in slowing down lateral erosion rates.

Given the current stability condition, the recovery of the stream within the project area could

take several years or even possibly decades to occur, and during this time could adversely affect

downstream resources. Because of these instabilities, the channel evolution rating of the reach

was considered to be functioning-at-risk but is quickly trending towards non-functioning, as

shown in Table 8.


Bank Height

Ratio1.51 FAR

Entrenchment

Ratio3.65 F





Dominant Bank

Ersoion RateH/H NF

Meander Width

Ratio1.8 - 6.8 FAR


Pool-to-pool

Spacing18 - 128 FAR

Pool Depth

Variability2.1 - 2.8 FAR

Water Appearance

and Nutrients

FWS Rapid


DetritusFWS Rapid

Assessment Visual NF

Presence Moderate FAR


Fish Presence Absent NF

FAR

2 - Hydraulics

UT6 Middle

Level and

CategoryParameter

Measurement

Method


Floodplain

ConnectivityFAR

3 -

GeomorphologyFAR

Lateral Stability

Bedform Diversity

4 -

PhysicochemicalFAR

5 - BiologyMacro

FAR




Table 8: UT6 Middle Channel Evolution Rating

4. Representative Reach - UT6 Lower

The Service determined that the overall function-based condition of UT6 Lower is Functioning

at Risk and is trending towards further instability. It is perennial and classified as an unstable

Rosgen E4. The stream is slightly incised but not entrenched and therefore, is connected to its

floodplain at larger than bankfull flood events. The floodplain is broad in relation to stream

channel width, with some concentrated flow paths from wetland seeps and sheet flow

concentrations nearby. Stream bank erosion is widespread and the channel exhibits very high to

extreme indices of bank erosion and near bank shear stress. The materials eroding from the

stream banks are contributing to the sediment load being delivered to the project areas

downstream. The pools and riffles are poor to moderately defined, while the pools depths are

moderate and promote some shelter for fish and macroinvertebrates. The riparian vegetation is

poor and consists primarily of mixed grasses and very few canopy trees or shrubs. The water

quality of the project area is fair and impaired mostly by temperature and stormwater runoff

higher in the watershed. The water throughout the reach is clear to cloudy, and limited detritus is

present.


there is presence of tolerant macroinvertbrates. Fish were seen in many of the pools throughout

this reach. Table 9 shows the parameters collected and function-based ratings given for this

reach.

UT6 Middle - Function-based Assessment Summary and Channel Evolution

Reach Length (ft)

Rosgen

Stream

Type


based Rating

352 C4 Unstable C4 F4B4c FAR




Table 9: UT6 Lower Function-based Assessment Table

UT6 Lower is undergoing channel evolution from an unstable Rosgen E4 stream type, towards

an unstable C4 stream type. It is undergoing some major adjustment. The stream is slightly

incised, likely due to previous land use changes and poor agricultural techniques. The channel

has reached an equilibrium in vertical adjustment, as it has matched the elevation of Piney

mainstem. Additionally, the stream cannot headcut upstream any further due to the box culvert

on Slacks Road. There is however, widespread active lateral erosion that will continue to occur

until addressed. Because of these instabilities, the channel evolution rating of the reach was

considered to be functioning-at-risk and trending towards not-functioning, as shown in Table

10.


Bank Height

Ratio1.23 FAR

Entrenchment

Ratio20.16 F





Dominant Bank

Ersoion RateVH/VH NF

Meander Width

Ratio0.5 - 3.5 NF


Pool-to-pool


Pool Depth

Variability2.0 - 2.6 FAR

Water Appearance

and Nutrients

FWS Rapid


DetritusFWS Rapid


Presence Rare FAR


Fish Presence Rare FAR

FAR

2 - Hydraulics

UT6 Lower

Level and

CategoryParameter

Measurement

Method


Floodplain

ConnectivityFAR

3 -

GeomorphologyFAR

Lateral Stability

Bedform Diversity

4 -

PhysicochemicalFAR

5 - BiologyMacro

FAR




Table 10: UT6 Lower Channel Evolution Rating

5. Representative Reach - UT6a Lower

The Service determined that the overall function-based condition of UT6a Lower is Functioning

at Risk and is trending towards stability. It is perennial and classified as an unstable Rosgen B4c.

The stream is moderately incised and moderately entrenched and therefore, is not connected to

its floodplain during bankfull and may only reach the floodplain area during larger flood events.

The floodplain is broad in relation to stream channel width, with some concentrated flow paths

from steeper terrain nearby. Stream bank erosion is widespread throughout the reach, which

exhibits indices of high to very high bank erosion and near bank shear stress. The materials

eroding from the stream banks are contributing to the sediment load being delivered to the

project areas downstream. The pools and riffles are moderately defined, however riffles are

short and pools are closely spaced. The pools depths have good variability and promote good

shelter for fish and macroinvertebrates. The riparian vegetation is fair, and consists primarily of

grasses, some shrubs and very few canopy trees. The water quality of the project area is fair and

impaired mostly by temperature and stormwater runoff for higher in the watershed. The water

throughout the reach is clear, and very little detritus is present.


there is presence of fish and tolerant macroinvertbrates. Table 11 shows the parameters collected

and function-based ratings given for this reach.

UT6 Lower - Function-based Assessment Summary and Channel Evolution

Reach Length (ft)

Rosgen

Stream

Type


based Rating

554 E4 Unstable E4 Unstable C4 FAR




Table 11: UT6a Lower Function-based Assessment Table

UT6a Lower is undergoing channel evolution from a Rosgen B4c stream type towards a stable

B4c. It is undergoing some major adjustment. The stream is slightly incised likely due to

previous land use changes and poor agricultural techniques. The channel has reached an

equilibrium in vertical adjustment as it has matched the elevation of UT6 downstream. There is

however, widespread active lateral erosion that will continue to occur until addressed. Because

of these instabilities, the channel evolution rating of the reach was considered to be functioning-

at-risk and trending towards not-functioning, as shown in Table 12.

Table 12: UT6a Lower Channel Evolution Rating


Bank Height

Ratio2 NF

Entrenchment

Ratio1.61 NF




Assessment Visual NF

Dominant Bank

Ersoion RateH/VH FAR

Meander Width

Ratio0.6 - 4.3 FAR


Pool-to-pool


Pool Depth

Variability>1.5 F

Water Appearance

and Nutrients

FWS Rapid


DetritusFWS Rapid


Presence Rare FAR


Fish Presence Rare FAR

FAR

2 - Hydraulics

UT6a Lower

Level and

CategoryParameter

Measurement

Method


Floodplain

ConnectivityNF

3 -

GeomorphologyFAR

Lateral Stability

Bedform Diversity

4 -

PhysicochemicalFAR

5 - BiologyMacro

FAR

UT6a Lower - Function-based Assessment Summary and Channel Evolution

Reach Length (ft)

Rosgen

Stream

Type


based Rating

348 B4c Unstable B4c B4c FAR




6. Biology

The Service only conducted visual monitoring on the Piney Run reaches for Level-5 biology

survey. While telling, this is merely an estimation method to generate inferences about the

condition of the system. In order to understand the biology of the system more comprehensively,

the MDNR MBSS team developed a monitoring plan to capture the baseline biologic condition

of the Piney Run project area. The MBSS team selected nine sites to track progress of the

restoration effort. Six sites were located on Piney Run and included three sites chosen to serve as

control sites for the restoration and three sites located on the portion that is to be restored (Figure

6). However, since the restoration effort has been split into a phased approach, the only MBSS

monitoring site within the current restoration area, and the area this report primarily focuses on,

is site 303 shown in Figure 6.

Figure 6: Piney Run MBSS Sampling Site Locations

The MBSS protocol focuses on key factors influencing biologic condition. Those factors include

temperature, benthic macroinvertebrates, fish, physical habitat, water chemistry, and

geomorphology. All data were collected using standard MBSS protocols. A detailed description

of these protocols is available in Stranko et al., 2007.

While geomorphic conditions can be a good representation of stream stability, water quality must

be intact to support biology. Water quality measurements taken include both continuous water

temperature and chemistry. The findings of the MBSS analysis showed that the water

temperature generally stayed below the threshold for tolerant cold water fish, such as brown

trout, but did not meet the standards to be considered a Maryland Use Class III stream. Similarly,




water chemistry was found to support tolerant cold water fish but conductivity and sulfate

concentrations could limit potential for abundant populations of trout.

Benthic macroinvetebrates index of biotic integrity, or “BIBI” was measured at each of the six

sites on Piney Run during the spring index period in 2014. The data collected assess the

macroinvertebrate species and richness in a given area. The sites surveyed on the Piney Run

project area ranged between 1.67 and 2.67 which plots low or “poor” as compared to the

reference sites. This means that currently, this portion of Piney Run does not provide the habitat

necessary to support these species. The most notable deficiency included the lack of detritus,

shading, and pool depth to provide shelter for these species. Additional data can be found in

Appendix D.

Fish indices of biotic integrity, or “FIBI” data, was also collected at each of the six sample sites

on Piney Run. Both the restoration sites and control sites scored well and were considered

“good” based on the criteria set forth by the MBSS protocol. The IBI values are shown below in

Table 13 and additional data can be seen in Appendix D.

Site

Control Restoration Reference

206 205 302 204 201 303 Jones Falls Timber Run Brice Run

Year 2014 2014 2014 2014 2013 2014 2014 2013 2014 2001 2013 2014 2013 2014

BIBI 2.33 2.33 1.67 2.67 2.00 2.67 2.67 3.00 3.00 5.00 4.67 4.00 3.67 3.00

FIBI 4.00 4.00 4.00 4.00 4.67 4.67 4.67 3.33 3.67 4.67 4.67 4.33 4.67 5.00

Table 13: Piney Run Indices of Biotic Integrity

VII. WETLAND ASSESSMENT

The Service and MDNR performed a wetland assessment throughout the Phase 1 project area to

verify the location of the National Wetlands Inventory (NWI) wetlands, and to identify other

existing wetland locations. This assessment was done in support of the project goal to increase

water quality through wetland enhancement and creation. Maximizing the amount of floodplain

complexity and wetland habitat are crucial factors that have benefits for water quality and

various Federal Trust species. Reconnecting a stream to its floodplain is one strategy that can

help reduce the amount of nitrogen found in stream systems. Stream restoration projects that

increase floodplain connectivity have been found to have higher denitrification rates than streams

that were restored with higher banks (Kaushal et al., 2008). Seasonal isolated wetlands, such as

vernal pools, provide excellent breeding habitat for species such as Spotted Salamander, Gray

Tree Frog and Northern Green Frog (Mitchell et al., 2006). Emergent wetlands provide food,

shelter, resting places, and nurseries for a variety of species, including migratory birds,

waterfowl, and other wildlife (Hayes, 1996.)




Figure 7: Piney Run wetland locations identified by MDNR

In general, the assessment found that the wetlands in the Phase 1 area matched up fairly well

with the NWI locations, with a few additional existing wetland locations identified. All of the

wetlands are considered to be emergent. Emergent wetlands are classified by the presence of

rooted herbaceous hydrophyte vegetation that is present over most of the growing season

(Cowardin et al., 1979). Figure 7 above shows the location of wetlands across the project area.

Opportunities for wetland creation include construction of vernal pools and oxbows, as well as

emergent wetlands with hummocks. Existing wetlands can be enhanced through removal of

invasive species and planting of obligate and facultative wetland plants. Further details on the

wetland assessment and recommendations can be found in Appendix E.




VIII. DESIGN DEVELOPMENT

This section presents the project constraints, restoration potential, design objectives, design

alternatives analysis, and project descriptions involved in the Piney Run Stream Restoration.

A. PROJECT AREA DELINEATION

The Service identified 16 distinct project areas (Figure 8) based primarily on the proposed

project reach design approach. The design approaches were selected through a design

alternatives analysis based on project goals, design objectives, existing conditions, constraints,

restoration potential, proposed uplift, impacts to existing resources, uncertainty, risk, and

implementation costs.

Figure 8: Project Reach Delineation




B. CONSTRAINTS

Constraints are man-made features that have the ability to influence stream restoration potential.

The Service identified a variety of constraints that will influence the final design solution for the

proposed project area. In some instances, the constraints are relatively minor and in other

instances they are major (Figure 9). In either instance, these constraints were addressed

throughout the design phase and were actively considered when developing design goals and

objectives.

Figure 9: Project Constraints

The largest project constraint is Piney Reservoir. It is located approximately 2 miles upstream of

Project Areas 7 and 8 and significantly affects the flow regime for these project areas. A

discharge analysis (Section VIII.F.4-Hydrologic and Hydraulic Analyses) determined that the




hydrograph influencing Project Areas 7 and 8 is primarily influenced by the drainage area

downstream of the reservoir versus the entire watershed drainage area. This is because

maximum flow releases from Piney Reservoir do not exceed flows greater than a 1 year storm

event. Therefore, Project Areas 7 and 8 have flow discharges and channel dimension

characteristics associated with the drainage area downstream of the reservoir, which is 4.6 square

miles versus the 15.2 square miles associated with the entire watershed. This constraint will

significantly influence design channel dimensions, specifically a smaller channel then what

would be expected for a project drainage area of 15.2 square miles.

The next largest constraint is the sanitary sewer that is parallel to Project Areas 1 through 8. The

sanitary sewer has the potential to influence the width of constructed floodplains within these

reaches. However, only the floodplain widths in Project Areas 5 and 7 are constrained by the

sanitary sewer. The floodplain width design objectives can be achieved in all of the other project

areas.

Roadway crossings are constraints in two locations within the project area. They constrict flood

flows and influence streambed and floodplain elevations. Flood flows are constricted in Project

Areas 5 and 6 because the bridge culverts are undersized and can cause back water effects

upstream of the road crossing and elevated stream shear stresses downstream. The streambed and

floodplain elevations cannot be raised in Project Areas 5, 6 and 7 because raising these

elevations can elevate flood levels and increase the potential for the roadway crossings to be

overtopped by flood flows.

The last constraint is a horse farm within Project Area 5. The horse farm pastures are near the

stream channel and limit design floodplain widths.

C. RESTORATION POTENTIAL

Restoration potential is the highest level of restoration or functional uplift that can be achieved

given the watershed health, reach-level function-based condition, stressors and constraints

(Harman et al., 2012). Based on these factors, the Service determined that all Project Areas can

achieve fully functioning Pyramid Levels 2 - Hydraulics and 3 - Geomorphology and partial

uplift for Pyramid Levels 1 – Hydrology, 4 – Physicochemical and 5 – Biology.

Potential for partial uplift of Pyramid Level 1 – Hydrology will come from eliminating

concentrated flows and increasing floodplain areas for flow attenuation. Project Areas 1, 2, 4, 5,

6, 9, 11, 13 and 15 have the highest potential for hydrological uplift because these reaches have

the largest existing sources of concentrated flow. Project Area 8, the farthest downstream project

area, has the greatest potential for an altered flow regime, specifically reduced peak flow floods.

This is possible through the proposed creation of large wetland areas in Project Areas 6 and 7.

However, the modeling required to determine this is not part of this study and therefore, cannot

be verified.

Restoration of Levels 2 and 3 functions are typically the easiest to achieve since they involve

direct, physical manipulation of stream channel dimension, pattern, and profile. Stream channel




parameters such as belt width, bank heights, floodplain width, facet feature lengths, slopes and

depths can be constructed to specifications considered functioning.

Potential for partial uplift of Pyramid Level 4 – Physicochemical is mainly influenced by

watershed health, but can be improved through reach level restoration activities. Stream bank

stabilization can significantly reduce sediment and nutrient inputs. Additionally, the creation of

floodplain wetlands can reduce sediment and nutrient loads. Wetland areas are proposed in

Project Areas 2 - 7 and 15. The effectiveness of floodplain wetlands will be greater in Project

Areas 3, 6 and 7 due to the larger extent of proposed wetland areas. Lastly, the establishment of

riparian vegetation can shade the stream and help reduce stream temperature.

Potential for partial uplift for Pyramid Level 5 – Biology will come from improved water quality

and in-stream habitat. Project Areas 2 – 7, 9, 12, and 15 have the highest potential for biological

uplift because these reaches have the poorest current in-stream habitat conditions.

D. DESIGN OBJECTIVES

Design objectives are based on project goals and project area restoration potential. The

objectives reflect the project goals but state specifically how the project will be completed. Thus,

design objectives are quantifiable and measurable. The goals of the study are to improve water

quality through sediment and nutrient reduction, create native riparian habitat for Yellow

Warbler, Eastern Wood-Peewee, Red-Shoulder Hawk and Acadian Flycatcher, and improve and

preserve downstream habitat for American Eel and other aquatic species through stream

restoration.

The Service developed, in coordination with MDNR, design objectives to address the design

goals. Varying existing stream conditions within the project require restoration efforts ranging

from relatively minor localized restoration activities to major, system-wide restoration activities.

Project Areas 1, 2, 8, 10 - 13 and 16 have localized instability conditions and will only require

minor restoration activities to meet the design goals. Project Areas 3 -7, 9, 14 and 15 have

system-wide instability conditions and will require significant restoration activities to meet the

design goals. Therefore, two sets of design objectives were developed (Table 14 and Table 15)

Piney Run Project Areas 1, 2, 8, 10 - 13 and 16 - Design Objectives

Level and

Category Parameters Design Objectives

Level 3 -

Geomorphology

1. Lateral

Stability

2. Sediment/Re

duction and

Trapping

3. Bedform

Diversity

4. Riparian

Buffer

1. Reduce stream bank erosion rates to match reference

erosion rates (bank migration/lateral stability).

2. Decrease sediment loads leaving the project to loads less

than entering loads entering the project.

3. Increase pool to riffle ratio to 60/40.

4. Create native riparian buffer for Yellow Warbler, Eastern

Wood-Peewee, Red-Shoulder Hawk, and Acadian

Flycatcher.

Table 14: Piney Run Project Areas 1, 2, 8, 10 - 13 and 16 - Design Objectives




Table 15: Piney Run Project Areas 3 -7, 9, 14 and 15 - Design Objectives

E. DESIGN ALTERNATIVES ANALYSIS

The purpose of the design alternatives analysis is to select the best restoration design solution

that meets the project goals and design objectives based on watershed and reach conditions,

restoration potential, and constraints. It focuses on how a specific design solution and restoration

activities could influence existing stream functions (both potential uplift and loss),

implementation costs, uncertainty and risk.

As stated above in the design objectives section, the project essentially has two broad restoration

needs: localized, minor restoration activities and system-wide, major restoration activities. A

design alternatives analysis was not conducted for Project Areas 1, 2, 8, 10 - 13 and 16 since the

Piney Run Project Areas 3 -7, 9, 14 and 15 - Design Objectives

Level and

Category Parameters Design Objectives

Level 1-

Hydrology

1. Concentrated

Flows

1. Eliminate concentrated flows.

Level 2 -

Hydraulics

2. Floodplain

Connectivity

3. Floodplain

Complexity

2. Set floodplain elevations to historic floodplain

elevations, where it exists. Create floodplain connection

to allow for inundation by flood flows less than bankfull

flows. Maximize valley width to create floodplain.

3. Increase floodplain complexity by eliminating

concentrated flows, creating wetlands and providing

areas to trap and store flood flows.

Level 3 -

Geomorphology

5. Lateral

Stability

6. Sediment

Reduction

7. Sediment

Transport

8. Bedform

Diversity

9. Riparian

Buffer

5. Reduce stream bank erosion rates to match reference

erosion rates (bank migration/lateral stability).

6. Decrease sediment loads leaving the project area to loads

less than entering the project area.

7. Transport the sediment supply being delivered to the

project area without excessive degradation or

aggradation.

8. Increase pool to riffle ratio to 60/40

9. Create native riparian buffer for Eastern Wood-Peewee,

Red-Shoulder Hawk, and Acadian Flycatcher and make

buffer width 150 ft wider than required meander width

ratio.

Level 4 -

Physicochemical

10. Nutrient

Levels 10. Reduce nutrient levels compared to existing conditions.

Level 5 -

Biology

11. Macros

12. Fish

11. Increase macro diversity and density conditions

compared to existing conditions

12. Increase fish diversity and density conditions compared

to existing conditions




restoration activities will be localized and minor. Additionally, potential adverse impacts to

existing resources will be avoided and/or minimized. However, a brief description of proposed

uplift and potential adverse impacts for each of these project areas is described below in Section

VIII.F.2-Proposed Project Area Descriptions.

For Project Areas 3 -7, 9, 14 and 15, the Service conducted a design alternatives analysis where

technically and economically feasible restoration solutions were developed and the overall

process was described to allow for meaningful and informed decision making.

1. Potential Design Alternatives

There are a variety of design restoration solutions available to achieve the primary design goal of

nutrient and sediment load reduction. Many of these approaches focus on increasing the

frequency, magnitude, and duration of flood flows to the floodplain. Essentially, as flood flows

interact with ground surfaces more frequently and for longer durations, there is a greater

potential for nutrient and sediment load reduction. However, stream energy and sediment supply

are two significant factors that influence floodplain inundation and the range of feasible design

solutions.

Streams with low energy and low sediment supply allow for the greatest variety of design

solutions because they are considered low risk. They are considered low risk because low

energy streams have less potential for excessive stream erosion, and limited sediment supply

streams, along with low energy, have less potential for excessive sediment deposition. One of the

most effective design approaches for streams with low stream energy and a limited sediment

supply involves designing a base flow channel. A base flow channel is designed so that

relatively frequent storm events can easily access and inundate the floodplain. To do this, base

flow channels typically have channel dimensions (area, width and depth) less than what would

be shown in a Hydrologic Regional Bankfull Discharge and Channel Characteristics Curve. This

design approach is commonly referred to as valley restoration and/or legacy sediment design.

Streams with moderate to high stream energy and sediment supply can be considered higher risk

projects and therefore, have a lower variety of design solutions. Moderate to high energy

streams have high shear stresses and the potential for excessive lateral and vertical erosion.

Moderate to high sediment supply streams have the potential to produce excessive sediment

deposition or excessive erosion depending on the stream energy. Excessive sediment deposition

occurs when the rate of deposition exceeds the ability for vegetation to establish, which in turn

accelerates bank and bed erosion. This means that the stream channel and floodplain are in a

constant state of flux, adversely affecting water quality and biology. If the sediment deposition

occurs at a rate that allows vegetation to establish, then bank and bed stability can be achieved.

Over time the sediment deposition will most likely form a stream channel that can transport the

sediment supply being delivered to the project area. Design approaches appropriate for these

stream conditions are commonly referred to as Natural Channel Design, and involve designing a

channel shaped to transport the sediment supply at bankfull flow (the channel forming discharge

flow). The channel dimensions associated with this design would correlate well with a

Hydrologic Regional Bankfull Discharge and Channel Characteristics Curve. It should be noted




though, that a base flow channel design could be used on these stream conditions if the sediment

deposition rate does not have adverse aggradation impacts.

2. Design Alternatives Analysis

The Service focused on developing potential restoration design alternatives that would result in

frequent overbank flows and floodplain inundation. They first evaluated the alternatives based

on how proposed channel and floodplain characteristics influenced sediment transport and

stream energy. This involved identifying sediments sources and load amounts and calculating

stream energy based on watershed size and valley slope. Each alternative was then evaluated

based on their ability to achieve the design goals and objectives and minimize potential adverse

impacts to existing resources.

a. Sediment Supply

There are two sources of sediment supply being delivered to the project area. One is from

eroding stream banks within the project area and the other is from sources upstream of the

project area. The sediment load being supplied from eroding stream banks within the project

area will be significantly reduced through restoration activities associated with the overall

proposed stream design.

To determine the sediment loads being supplied from upstream watersheds, the Service

conducted a rapid watershed assessment of the four watersheds upstream of the project area

(Figure 3: Piney Run Watershed and Subwatershed Delineation). Project Area 7 is influenced by

the Piney Run Watershed; Project Areas 3 – 6 are influenced by UT6 Watershed; Project Area 9

is influenced by UT6e Watershed and Project Area 15 is influenced by UT6a Watershed. A

detailed description of sediment supply for each watershed is described in Section V-Watershed

Assessment. However, below is a brief description.

Piney Run Mainstem: Piney Run watershed sediment supply is low. Sediment is being trapped

by Piney Reservoir, which is located approximately 2 miles upstream of the project area.

Additionally, Piney Run mainstem and the tributaries between Piney Reservoir and the project

area are mostly stable and producing low sediment supplies.

UT6 and UT6e: UT6 and UT6e watersheds have low to moderate sediment loads. Route 32

crosses both tributaries at the upstream ends of the project areas. The roadbed of Route 32, as it

crosses UT6 and UT6e, is significantly elevated and the culverts are undersized for flood flows.

Additionally, the floodplains of UT6 and UT6e, upstream of Route 32 and outside of the project

areas, are low-sloped and wide. These conditions, combined, result in effective sediment

trapping and thus result in a low sediment supply being delivered to UT6 and UT6e.

UT6a: UT6a watershed has a moderate to high sediment supply that is coming from stream bank

erosion upstream of the project area. However, the overall sediment load is low to moderate




since the drainage area is relatively small (0.76 square miles) and the total stream length,

upstream of the project area, is relatively short (approximately 2,800 feet).

In summary, three out of the four watersheds have low sediment supplies, while one has a

moderate to high sediment load. Therefore, all project areas, except Project Area 15, can have

stream channel dimensions less than bankfull characteristics without resulting in excessive

sediment deposition, when only considering sediment supply. Stream energy and floodplain

availability must also be considered before determining whether a less than bankfull channel is

sustainable over time. For Project Area 15, which has a moderate to high sediment supply, a

restoration solution can be designed that will allow the sediment to deposit at a rate at which

stream stability can be maintained over time. This can occur through the creation of large, well-

vegetated floodplain areas adjacent to the project area.

b. Stream Energy

Stream energy, which can be related to stream slope, varies among the project areas. Generally,

stream channel dimensions of less than bankfull characteristics can be designed for streams with

slopes up to 0.01 ft/ft by minimizing flow depths as flow volumes increase. This can be done by

increasing channel width ratios and providing large floodplain areas adjacent to the stream.

However, a hydraulic analysis is required to demonstrate that stream energy levels associated

with a proposed design will not result in excessive erosion or deposition. The Service did

conduct a hydraulic analysis and the results are described in detail in Section VIII.F.4-

Hydrologic and Hydraulic Analyses. In summary, the existing and proposed stream shear

stresses, velocities and sediment competence demonstrate that the project areas will not have

excessive degradation or aggradation. Therefore, project areas can be designed to stream

channel dimensions of less than bankfull characteristics shown on regional curves.

c. Floodplain Characteristics

Floodplain widths, elevation and shape are critical aspects when developing stream restoration

solutions. An adequate floodplain width and appropriate shape is needed to reduce stream

energy. Width is needed to create storage for flood flows as flow volumes increase. An

appropriate valley shape (e.g., following the fall of the valley versus following the meander

pattern of the stream channel) is needed to reduce flood flow restrictions. A high floodplain

width/depth ratio assists in reducing flood flow depths as flow volume increase, thus reducing

stream and floodplain shear stresses and energy. The hydraulic analysis described above

demonstrates that the floodplain designs associated with the overall proposed stream restoration

solutions will maintain stream and floodplain stability over time. This includes Project Area 15

which was demonstrated to have a moderate to high sediment supply. The proposed floodplain

width of Project Area 15 is adequate enough to allow for a floodplain sediment deposition rate

that will not result in potential adverse impacts.

The floodplain design elevation is influenced by two factors associated with the Piney Run

project. The first are the roadway crossings that were described above in Section VIII.B-




Constraints. The second is a design objective to excavate the floodplain to historic floodplain

elevations. The roadway crossings will influence streambed design elevations for Project Areas

5, 6 and 7. Raising streambeds will elevate flood levels and increase the potential for roadway

crossings to be overtopped by flood flows. Therefore, the floodplain design elevation cannot be

higher than the existing floodplain elevation for these project areas, but could be designed to a

lower elevation without adverse impacts to the roadway crossings.

To determine the historic floodplain elevation, MDNR contracted with Dorothy Merritts of

Franklin and Marshall College. Trenches were dug at various locations within the existing

floodplain throughout the project area. Data collected from the trenches demonstrated that a

historic floodplain exists in Project Areas 6 and 7. The historic floodplain elevation is

approximately two to three feet lower than the existing floodplain elevation. Additionally, the

data showed that the historic floodplain extends to the valley toe-of-slopes on both sides of the

stream. Locations of the soil trenches and the corresponding data can be found in Appendix F.

Designing a lower floodplain elevation would reduce the potential for flood flows to overtop the

roadway crossings, but could adversely impact existing floodplain natural resources (e.g.,

riparian vegetation, wetlands, etc.). However, this is not a significant issue with the Piney Run

project because almost all of the floodplain areas proposed to be lowered consist primarily of

fallow pasture areas of low ecological value. There are some wetland areas that will be

impacted, but the overall design proposes the creation of wetlands greater in total area than the

existing wetlands. Furthermore, the existing wetlands have low ecological value because of poor

hydrology and vegetation. The proposed wetland areas will have much higher ecological value.

A detailed description of the proposed wetlands and potential impacts are in Section IX-Impacts

to Existing Resources.

d. Stream Channel Characteristics

The analysis of sediment loads, stream energy, and floodplain availability demonstrate that a

stream channel can be designed to channel dimensions of less than bankfull stream characteristic.

This type of stream channel can be either a single or multi-thread channel, or even possibly more

of a wetland complex mosaic across the entire floodplain without a defined stream channel. The

two primary factors that influence which stream channel design can be maintained over time are

valley slope and watershed size.

Reference stream and wetland systems data has been collected by EPR over the past several

years, with the goal of developing a tool to predict channel formation. These data have been

collected primarily from Coastal Plain reference reaches and wetlands, but more recent data has

included inland regions and data from several different states in the Southeastern United States.

Reference streams and flowing wetlands have been surveyed to evaluate the conditions that lead

to channel formation under natural conditions. The analysis of the data, in fact, shows that the

formation of stream channel features is strongly correlated with valley slope and watershed size.

In simplest terms, the energy of flowing water is determined by its velocity and depth.

Formation of a defined stream channel begins when flowing water has sufficient energy to begin

the processes of scour, headcutting, and sediment transport.




Valley slope is used as a surrogate for flow velocity: the higher the valley slope, the higher the

velocity of flowing water in the stream system during storm events. Drainage area was used as a

surrogate for flow depth and quantity: the higher the drainage area, the higher the volume of

water (and depth of flowing water) for a given storm event. Each surveyed reference

stream/wetland system was classified as either a poorly defined/braided channel or well

defined/single thread channel, based on visual observations during field surveys. Valley slope

and drainage area data are plotted for each surveyed reference reach are provided in Figure 10

(Tweedy, K.L., 2008.) below. The data for the Piney Run design reaches are also plotted for

comparison. Reaches that plot above the transition line tend to be single-thread stream reaches,

whereas reaches that plot below the transition line tend to be braided or flowing wetland reaches.

The further away the reaches plot from the transition line, the more prevalent the channel form.

For all of the Piney Run design reaches, the data plot well above the transition line; therefore, the

prediction is that under natural conditions, single-thread stream channels would be expected for

the Piney Run stream reaches.

Figure 10: Channel formation tool with associated data from Piney Run plotted (Tweedy, K.L., 2008.).

While a single-thread stream channel is expected for the Piney Run stream reaches, the Service

did consider what would happen if no channel was constructed. It is possible to implement a

design approach without a defined stream channel that would allow for a channel to form over

time. However, this would most likely result in considerable erosion and loss of sediment and

pollutants that would be delivered to downstream resources. Adverse impacts would occur to

aquatic species and the habitat needed for the project targeted species could possibly not evolve.

Thus, not actually maximizing the project nutrient and sediment load reduction objectives.




Therefore, the Service proposes that a single-thread channel be designed for all Piney Run

project reaches.

3. Preferred Plan

Based on the alternative analysis, the Service proposes a combined natural channel design and

valley restoration approach to be applied to the Piney Run Project Areas 3 -7, 9 and 15. This

would involve designing a channel and floodplain system where the proposed channel

dimensions are less than what would be shown on the Piedmont Regional curve (McCandless

and Everett, 2002) and flood flows of less than a bankfull event would access the adjacent

floodplains. The sizing of the design channel dimensions was verified through hydrologic and

hydraulic modeling to ensure that proposed stream reaches would be self-sustaining and would

not aggrade or degrade over time. This approach meets project goals and design objectives,

provides the greatest functional uplift, results in the least amount of adverse impacts to existing

functions, is based on reference conditions and considered low risk.

a. Potential Functional Uplift

This approach, if implemented, will result in functional uplift through Level 5 – Biology.

Assessment parameters in Level 2 - Hydraulics and Level 3 – Geomorphology will be fully

functional while assessment parameters in Level 4 – Physicochemical and Level 5 – Biology will

remain functioning-at-risk but have partial functional uplift. As was stated in the restoration

potential section, restoration of levels 2 and 3 functions are typically the easiest to achieve since

they involve direct, physical manipulation of stream channel dimension, pattern, and profile. The

expected Level 4 uplift will be associated with nutrient reductions. This will occur as a result of

the proposed bank stabilization activities, floodplain reconnection, and creation of extensive

wetland systems. The expected Level 5 - Biology uplift will be associated with improvements to

macroinvertebrate and fish communities through the increase of available in-stream habitat. The

increase of available in-stream habitat is a result of improved bedform diversity functions

associated with Level 3 proposed restoration objectives.

b. Potential Adverse Impacts

Implementation of the preferred approach will involve channel realignment and floodplain

excavation. This type of activity could adversely affect existing riparian vegetation. However,

the majority of the existing riparian vegetation was assessed to have low ecological value and

was rated as Functioning-at-Risk. Therefore, any potential realignment or grading will not

adversely affect the existing riparian vegetation. There are some riparian vegetation areas

though, that do have a higher ecological value. In these areas, the stream reaches have minimal

instability issues and the Service proposes only to implement minor and localized restoration

activities in order to minimize potential adverse impacts.

There are several wetland areas throughout the project area. These wetland areas range in

ecological value from low to high. Existing wetlands with high ecological value are being

avoided and enhanced with proposed plantings. Some of the existing wetlands with low

ecological value will be impacted by the implementation of proposed floodplain areas. However,




the impacts to these existing wetlands will be self-mitigating through the creation of new wetland

areas that significantly exceed the existing wetland area acres and ecological value. Details of

wetland creation are presented in Section VII-Wetland Assessment.

Some temporary effects may occur during construction. These effects are typical of stream

restoration projects regardless of which design approach is implemented and generally include

displacement of aquatic species and increases in turbidity. To reduce these potential impacts, the

Service recommends a construction sequence where new channel construction occurs first and

then connection to the existing channel occurs. Specific potential adverse impacts for each

project area are presented below in Section VIII.F.2-Proposed Project Area Descriptions and

summarized in Section IX-Impacts to Existing Resources.

c. Uncertainty and Risk

Project uncertainty and risk is used to determine the likelihood of the project to succeed in

achieving the stated goals and objectives, as well as the consequences if they are not met. There

are three classes of uncertainty: 1) uncertainty of knowledge, 2) uncertainty about quantities and

3) uncertainty about models (Yoe, 1996). The components of risk are then split into two parts:

1) risk evaluation (i.e., how risky is a situation?) and 2) risk management (i.e., what should be

done about the risk?) (Yoe, 1996).

Uncertainty and risk are first explored when considering the level of detail in the existing

conditions assessment. Increases in uncertainty and risk can occur with limited or inaccurate

documentation of existing resource conditions. To reduce uncertainty in knowledge and

quantities, the Service developed a comprehensive and detailed existing conditions data set by

conducting rapid function-based watershed and reach level assessments of the entire project area

and detailed function-based assessments of representative stream reaches (Sections III-Project

Process Methodology, V-Watershed Assessment and VI-Reach Level Assessment). Additionally,

the Service documented historic stream conditions and determined what stream conditions would

naturally form and be self-maintaining by current day watershed and reach level existing

conditions. This understanding was drawn from the channel evolution evaluation conducted as

part of the reach level function-based assessment. The channel evolution evaluation not only

describes what stream condition could be maintained but it also describes what evolution must

occur before quasi-equilibrium can be achieved. This is important because it influences the

design objectives (discussed below) and level of restoration required. A stream that is near quasi-

equilibrium may only require some localized restoration activities to meet design goals and

objectives versus a stream that is highly unstable. A highly unstable stream would most likely

need to undertake significant restoration activities to meet design goals and objectives. A greater

level of restoration effort leads to a greater potential for higher project uncertainty and risk.

However, the Service has minimized project uncertainty and risk with a detailed understanding

of existing conditions and through the development of suitable and achievable restoration design

goals and objectives.

Uncertainty and risk is then addressed in the project design goals and objectives. Project goals

and objectives that are poorly defined and/or overly ambitions create uncertainty in project

expectations. Therefore, critical evaluation of project success requires specific, well defined, and




measurable design objectives to be identified early. Therefore, the Service developed measurable

and quantifiable design objectives for each Piney Run project area, which are listed in Section

VIII.D-Design Objectives.

The ability to meet design objectives is also influenced by site suitability. As stated above,

stream functions that would naturally form and be maintained over time would have low

uncertainty and risk, in comparison to a high uncertainty and risk with functions that would not

naturally form and be maintained. Along with the assessment of historic conditions and channel

evolution, the Service used a reference reach design approach in developing design criteria to

reduce site suitability uncertainty and risk. The concept of a reference reach design approach is

to duplicate channel dimensions, pattern and profile of a stable, self-maintaining stream reach

within a proposed project area. It involves collecting stream reach data from stable streams in

similar watershed conditions as the proposed project watershed and developing design criteria

specific to the proposed project area. The Service has collected reference data from appropriate

stable stream reaches and developed design criteria for each project area. A more detailed

description of how design criteria were developed is in Section VIII.F.1-Design Criteria and

project reach specific design criteria are located in Appendix G.

The final component of project uncertainty surrounds the restoration design modeling

verification. The ability of a model to predict accurate conditions influences uncertainty.

Decreases in uncertainty can be achieved through using models that have proven capabilities in

predicting actual conditions. Therefore, the Service used HEC HMS and HEC RAS to model

hydrologic and hydraulic project conditions since these models are the most widely accepted and

used models. The Service calibrated the HEC HMS by using 12 years of collected flow data

from Piney Reservoir and calibrated the HEC RAS by using field collected roughness data and

U. S. Geological Service flow regression equations (a standard practice). The Service used these

models to test and verify stream stability of the proposed stream design. Specifically, the Service

evaluated stream energy to determine if the proposed stream channel dimensions, profile, and

pattern would not aggrade or degrade over time. The results of the modeling analysis, shown in

Section VIII.F.4-Hydrologic and Hydraulic Analyses, demonstrate that the proposed design will

be maintained over time.

The final step associated with risk is managing the potential risk. In any project, there will

always be unpredictable natural and/or anthropogenic disturbances that could influence the

performance of a proposed restoration project. The Service has taken steps towards reducing

unpredictable uncertainty and risk. For example, the Service used local and state planning

documents to predict potential future anthropogenic disturbances, described in Section V-

Watershed Assessment. Additionally, the Service has proposed the creation of extensive

floodplain areas to address any potential episodic natural events (e.g., extreme storm events) that

could impact project effectiveness. However, it is impossible to predict all potential future

actions that could affect the proposed restoration project, but risk management is a way to

address the uncertainty of future disturbances. Risk management can be incorporated in the

maintenance/adaptive management and monitoring plans. Therefore, the Service recommends

that a maintenance and monitoring plan be developed, that describes how the proposed




restoration project shall be monitored, when maintenance will be required, and who is

responsible for the monitoring and maintenance.

The Service considers the Piney Run Stream restoration project to be low uncertainty and risk

because of the comprehensive, detailed existing conditions data set; suitable and quantifiable

design objectives; reference reach based design criteria, design modeling verification, restoration

level of effort, and the proposed monitoring and maintenance plan. Bottom line, the Service is

proposing a stream restoration design that would naturally form and be self-maintaining over

time, given current day Piney Run watershed and reach level existing conditions.

d. Implementation Costs

The implementation of Phase 1 Piney Run restoration project will include planting and wetland

enhancement along nearly 4.23 miles of stream and restoration lengths of over 16,000 linear feet.

Given the size and scope of this effort, the implementation, efficiency and cost-effectiveness of

the project is dependent upon a variety of construction-based challenges.

The Piney Run project area is owned and managed by entities of the state of Maryland as well as

Carroll County. Access is relatively unrestricted throughout the project site and does not pose to

be a significant problem. However, due to the scale of the project, a significant amount of access

points are required to efficiently work on restoration areas. Currently, the design proposes

approximately seven access points. These locations can be found on the Erosion and Sediment

Control sheets within the construction plan set. Access points were chosen to minimize the

amount of impacts to the existing natural resources and also provide reasonably close access to

restoration areas. Because the project area is either agriculture or wooded, it is presumed that

access will be adequate throughout the construction term. Additionally, since preferential access

is readily available and has not been limited, construction will be more efficient, lessening

overall construction costs.

The scale of the Piney Run restoration poses its own set of challenges during the implementation

phase. As mentioned previously, the Piney Run watershed is designated as a Use Class III which

restricts in channel work from October 1 through April 1. This limits in channel construction to 6

months per year. Due to this, the site area, and overall project scope, it is likely that the term of

the construction could run upwards of three construction “seasons” based on the selected

contractor and available resources. Since it is likely that it will take multiple seasons, this will

negatively impact overall cost due to the mobilization / demobilization efforts that will have to

take place more than once.

The final construction plan set calls for the excavation of 63,400 cubic yards of earthen material.

Most of this material is being generated from the lower portion of UT6 and adjacent to the main

stem of Piney Run. While it is usually the goal of any excavation project to balance cut/fill

volumes, due to the design methodology chosen in these locations, the excavation and excess

volumes are unavoidable. It has been determined that nearly 20,000 cubic yards will be reused

but a balance of 43,800 cubic yards will remain as excess or “spoil” material. The removal and

relocation of this excess material accounts for nearly 30% of the overall costs of the project,

which makes it the most substantial cost of the restoration effort.




A variety of in-stream structures were used for the restoration of Piney Run and its tributaries.

These structures utilize items naturally found on the landscape, such as rock and logs to promote

stability within the stream channel and valley floor. It is not anticipated that any large quantity of

suitable structure rock will be located on site, and therefore must be imported from local

quarries. Due to this fact, the design team proposed a mixed structure ensemble that utilizes

woody material such as trees and limbs to serve similar purposes as well as promote additional

habitats within the structures. While there is not an abundance of trees to be cleared on the site,

the costs associated with this woody material are usually less than that of stone. With this being

said, it also offers the opportunity to reuse trees that may need to be removed for construction

access or floodplain grading. Utilizing all available material on-site minimizes necessary import

costs and the design team sought those opportunities out where available.

An extensive planting plan has also been developed for the restoration of Piney Run and its

tributaries. This plan seeks to enhance existing riparian habitat but also create robust riparian

conditions along the areas of newly restored stream. Again, the costs associated with this

planting effort are unavoidable and also crucial to the success of the project. The establishment

of a dense riparian corridor instantly stabilizes loose soils and instantly provides filtration

properties to overland flows. The design team specifically selected appropriate riparian plants

that will establish quickly and recommended quantities that will result in the creation of a dense

riparian habitat.

There are many additional tasks that play into the construction costs associated with this project,

including labor costs and state and local permitting requirements, however, those noted above

are most critical. Based on the construction plan set as well as historic project implementation

cost data compiled by the design team, it is estimated that this project will cost approximately

six million dollars to complete. A more detailed breakdown of the project costs by reach can be

found in Appendix H.

F. DESIGN DEVELOPMENT

The Piney Run stream restoration project offered the unique opportunity to employ a variety of

ecologic restoration design methodologies to properly address areas of instability or lacking

habitat while using location appropriate restoration measures to meet the project goals of the

partners.

While not exclusive, the project generally uses Natural Channel Design (NCD) principals

throughout much of the project area. NCD uses form and process to develop stream restoration

designs. Form is the structural features of a stream and includes channel dimensions, pattern and

profile. It is based on reference stream conditions that are the same stream type, valley type,

vegetation type, and bed material. Process is the analytical assessment of a design. Hydraulic

and sediment calculations are conducted to determine the potential stability of the design.

Adjustments are made to the design based on the results of the analytical assessment and then the

design is re-assessed. This iterative process continues until the analytical assessment shows that

the design will be self-maintaining and that the channel dimensions, pattern and profile match

reference conditions.




A variation of the NCD process was also used to better promote floodplain connection and

complexity. Rigorous hydraulic modeling was conducted to reduce channel dimension as much

as possible to safely convey sediments and flows while allowing higher frequency storm flows to

reach complex wetland areas. This particular variation is found lower in the drainage area where

a larger floodplain is present. These areas were found to have relic floodplains identified below

the existing floodplain and excavation was proposed to reach the historic floodplain soils to

return these areas to their historic state.

In this section, the Service documents how the NCD process was applied and modified to the

project areas. It contains design criteria, proposed plan, in-stream structures, hydrologic and

hydraulic assessment, sediment transport assessment, and proposed vegetation plans.

1. Design Criteria

Design criteria was compiled by standardizing existing channel plan, profile and dimension of

design criteria developed by the Service and other sources (Harman et al., 2011; Flores, 2011;

Hay, 2006; NRCS, 2007; and Leopold et al, 1992). In addition, the Service was able to locate

stable riffles throughout the project area, which were free to adjust and had good bankfull

indicators., Cross sections were taken at these riffles to model the design geometry criteria. The

measurements from these cross sections were verified and extrapolated using the regional curve

calculations, resistance equations, and natural channel design reference ratios for Rosgen C4 and

B4 stream types, described below in Section VIII.F.4-Hydrologic and Hydraulic Analyses.

Additionally, MDNR contracted with Dorothy Merritts of Franklin and Marshall College to

determine the historic floodplain elevation, which was used to set the proposed floodplain

elevation. The design criteria are located in Appendix G – Design Criteria.

2. Proposed Project Area Descriptions

The overall Piney Run Stream restoration design has 16 individual project areas. A brief

description of each project area design, along with potential uplift and adverse impacts is

provided below. Details of proposed project area plans can be found in the Piney Run Stream

Restoration Design Plan Set.

a. Project Area 1

Project area 1 only requires corrective actions in isolated areas of instability. The existing and

proposed design stream type for Project Area 1 is a Rosgen B4. A Rosgen B4 stream type is a

non-meandering stream that dissipates energy vertically within the bed of the channel and has a

floodplain as small as 1.4 times its bankfull width.

The Service has determined that Project Area 1 is generally stable and still connected to its

floodplain, so it does not require any additional action to meet the Level 2 –Hydraulic design

goal of floodplain reconnection / more frequent inundation.

Only minor stability fixes are required to achieve the Level 3 – Geomorphology lateral stability

and sediment load reduction design goals. The Service plans to address isolated instabilities




within the stream channel while maintaining existing plan form, profile and dimension. To

promote bedform diversity and lateral stability, in-stream structures will be installed to promote

pool scour and glide and riffle formation while protecting adjacent banks. While proper plan

form is important, the Service has recognized that stability cannot be achieved without the proper

riparian conditions. The Service has proposed bio-engineering and dense riparian planting that

will be done in association with the isolated stability fixes.

Level 4 – Physicochemical design objectives of reducing nutrient loads will be met primarily

through the bank stabilization. Level 5 – Biology design objectives of increasing

macroinvertebrate and fish population diversity and densities will be met primarily through the

bedform diversity improvements and in-stream structures.

Areas adjacent to Project Area 1 consist primarily of mature mixed hardwood forests, as

described in Section VI-Reach Level Assessment. Therefore, the potential adverse impacts,

other than those described above in Section VIII.E.3.b-Potential Adverse Impacts, would be

temporary access requirements through the floodplain and light damage to the existing riparian

corridor. These impacts would be mitigated accordingly.

b. Project Area 2

Similarly to Project area 1, Project Area 2 only requires corrective actions in isolated areas of

instability. The existing and proposed design stream type for Project Area 2 is a Rosgen B4. A

Rosgen B4 stream type is a non-meandering stream that dissipates energy vertically within the

bed of the channel and has a floodplain as small as 1.4 times its bankfull width.

The Service has determined that Project Area 2 is generally stable and is still generally

connected to its floodplain and does not require any additional action to meet the Level 2 –

hydraulic design goal of Floodplain reconnection / more frequent inundation. Additionally, the

upstream most portion is well armored by natural stone as well as placed stone from an adjacent

utility easement.


and sediment load reduction design goals, the Service plans to address isolated instabilities

within the stream channel maintain existing planform, profile and dimension. To promote bed

form diversity and lateral stability, in-stream structures will be installed to promote pool scour

and glide and riffle formation while protecting adjacent banks. While proper plan form is

important, the Service has recognized that stability cannot be achieved without the proper



Level 4 – Physicochemical design objectives of reducing nutrient loads will be met primary


macroinvertebrates and fish population diversity and densities will be met primary through the





Areas adjacent to Project Area 2 consist primarily of mature mixed hardwood forests that slowly

open up to relic pasture and grass meadow, as described in Section VI-Reach Level Assessment.

Therefore, the potential adverse impacts, other than those described above in Section VIII.E.3.b-

Potential Adverse Impacts, would be temporary access requirements through the floodplain and

light damage to the existing riparian corridor. These impacts would be mitigated accordingly.

c. Project Area 3

The proposed design stream type for Project Area 3 is a modified Rosgen C4. A modified

Rosgen C4 stream type is a meandering stream that dissipates energy laterally across the

floodplain but has channel dimensions less than what would be shown in the Piedmont Regional

Curve (McCandless and Everett, 2002). Additional supporting information describing how the

proposed cross sectional area was derived is presented in Section VIII.F.4- Hydrologic and

Hydraulic Analyses. This approach will allow the Service to achieve the Level 2 - Hydraulic

design goal of connecting flood flows of less than bankfull flows to the floodplain.

Currently, the project area is disconnected from its floodplain and needs to be reconnected to

allow for adequate energy dissipation and to allow for more frequent out of bank flow events.

The Service proposes a moderate channel lift coupled with excavation of a new floodplain. The

proposed elevation of the floodplain is targeted to rehydrate existing wetlands as well as limit the

amount of necessary excavation and impact to adjacent resources. Along with the channel

relocation and floodplain excavation, some areas of the existing channel will be allowed to

remain open, thus providing vernal pools, as additional back water habitat for fish and

amphibians. This design concept will allow the Service to achieve the Level 2 - Hydraulic design

goal of reconnecting to the historic floodplain and maximizing valley width. Furthermore, the

proposed floodplain areas will consist of a wetland mosaic to meet the Level 2 - Hydraulic

design goal of increasing floodplain complexity and eliminating concentrated flows.

To achieve the Level 3 – Geomorphology lateral stability and sediment load reduction design

goals, the Service plans to re-align the stream channel to create meanders and belt widths that

would promote increased lateral stability. The proposed alignment was placed to minimize over

excavation and to avoid potential conflicts with the existing sewer line. To promote bed form

diversity, in-stream structures will be installed to promote pool scour and glide and riffle

formation while protecting adjacent banks. While proper plan form is important, the Service has

recognized that stability cannot be achieved without the proper riparian conditions. The Service

has proposed dense wetland riparian plantings that will extend beyond the limits of the design

belt width to increase the stability of the system.


through the bank stabilization and the extensive wetland areas. Level 5 – Biology design

objectives of increasing macroinvertebrate and fish population diversity and densities will be met

primarily through the bedform diversity improvements, in-stream structures, and the extensive

wetland areas.

Areas adjacent to Project Area 3 consist primarily of old fallow fields of low ecological value, as

described in Section VI-Reach Level Assessment. Therefore, the only potential adverse impacts,




other than the ones described above in Section VIII.E.3.b-Potential Adverse Impacts, are to 0.72

acres of existing, low ecological value wetland areas; 0.53 acres of which are temporary impacts.

The impacts to these existing wetlands will be self-mitigating through the creation of new

wetland areas that significantly exceed the existing wetland area in acres and ecological value.

Details of wetland creation are presented in Section VII-Wetland Assessment. Exact figures and

locations of wetland impacts are referenced in Section IX-Impacts to Existing Resources and

Appendix L.

d. Project Area 4

Like Project Area 3, the proposed design stream type for Project Area 4 is a modified Rosgen

C4. A modified Rosgen C4 stream type is a meandering stream that dissipates energy laterally

across the floodplain but has channel dimensions less than what would be shown in the Piedmont

Regional Curve (McCandless and Everett, 2002). Additional supporting information describing

how the proposed cross sectional area was derived is presented in Section VIII.F.4-Hydrologic

and Hydraulic Analyses. This approach will allow the Service to achieve the Level 2 - Hydraulic

design goal of connecting flood flows of less than bankfull flows to the floodplain.



The Service proposes a moderate channel lift coupled with excavation of a new floodplain. The

proposed elevation of the floodplain is targeted to rehydrate existing wetlands as well as limit the

amount of necessary excavation and impact to adjacent resources. Along with the channel

relocation and floodplain excavation, some areas of the existing channel will be allowed to

remain open, thus providing vernal pools as additional back water habitat for fish and

amphibians. This design concept will allow the Service to achieve the Level 2 - Hydraulic design

goal of reconnecting to the historic floodplain and maximizing valley width. Furthermore, the

proposed floodplain areas will consist of a wetland mosaic to meet the Level 2 - Hydraulic

design goal of increasing floodplain complexity and eliminating concentrated flows.



would promote increased lateral stability. The proposed alignment was placed to minimize over

excavation and to avoid potential conflicts with the existing sewer line. To promote bed form

diversity, in-stream structures will be installed to promote pool scour and glide and riffle

formation while protecting adjacent banks. While proper plan form is important, the Service has








wetland areas.






other than the ones described above in Section VIII.E.3.b-Potential Adverse Impacts are to 0.56






Appendix L.

e. Project Area 5

The proposed stream type design for Project Area 5 is a modified Rosgen B4c. A Rosgen B4c

stream type is a moderately entrenched stream with low sinuosity. The sewer alignment along

the left bank and property line along the right bank are constraints that prevent the ability to

achieve the meander ratio needed to create a C4 stream type. Channel realignment is mainly

limited from a downstream bridge constraint. Currently, the stream enters the culvert under

Slacks Road off-center. Therefore, the channel will be realigned to center the flow through the

Slacks Road culvert and restore a limited meander pattern due to human constraints. Channel

dimensions will be sized smaller than would be expected in the appropriate regional curve to

achieve greater floodplain connectivity (described in Section VIII.F.4-Hydrologic and Hydraulic

Analyses).


allow for adequate energy dissipation and to allow for more frequent out of bank flow events. A

Rosgen Priority Level 2 approach will be used to excavate a floodplain bench to restore

connectivity to the historic floodplain elevation and provide more frequent floodplain inundation.

The floodplain bench will be approximately two to three feet lower than the existing floodplain

elevation and extend slightly beyond the meander width of the proposed channel. Excavating the

floodplain elevations to the valley toe-of-slopes will allow the Service to achieve the Level 2 -

Hydraulic design goal of reconnecting to the historic floodplain, maximizing valley width, and

connecting flood flows of less than bankfull flows to the floodplain. Furthermore, the proposed

floodplain areas will consist of a wetland mosaic to meet the Level 2 - Hydraulic design goal of

increasing floodplain complexity and eliminating concentrated flows.

The achievement of Level 3 – Geomorphology lateral stability and sediment load reduction

design goals in a B4c channel requires more structures to be placed to ensure stability from

energy dissipation in small scour pools as less energy is dissipated through a meandering plan

form. Bank stability will be provided from the installation of rock cross vanes and rock/log j-

hooks to center the flow velocities through the middle of the channel, as well as through robust

stream bank planting that will provide stabilization through root establishment.








wetland areas.


described in Section VI-Reach Level Assessment. While there are no existing wetlands within

Project Area 5, creation of new wetland areas are proposed that will result is significantly

functional uplift. Details of wetland creation are presented in Section VII-Wetland Assessment.

f. Project Area 6




Curve, similar to project area 5 and described in Section VIII.F.4-Hydrologic and Hydraulic

Analyses. Constraints from the sewer alignment in Project Area 5 continue along the left bank in

Project Area 6, however, an open floodplain on the right bank will be created and planted for

emergent wetland creation where the existing channel is abandoned during realignment.


allow for adequate energy dissipation and to allow for more frequent out of bank flow events. A

Rosgen Priority 2 restoration approach will excavate a bankfull bench along both sides of the

stream at an elevation close to the historic floodplain. The bench will extend beyond the meander

width of the realigned channel and incorporate portions of the existing channel to be filled. The

floodplain will be approximately two to three feet lower than the existing floodplain. This

reconnection will allow the Service to achieve the Level 2 - Hydraulic design goal of

reconnecting to the historic floodplain, maximizing valley width, and connecting flood flows of

less than bankfull flows to the floodplain. Furthermore, the proposed floodplain areas will

consist of a wetland mosaic to meet the Level 2 - Hydraulic design goal of increasing floodplain

complexity and eliminating concentrated flows.



would promote increased lateral stability. The proposed alignment was placed to avoid potential

conflicts with the existing sewer line and to provide a more stable realignment plan form with the

confluence at the Piney Run mainstem. To promote bedform diversity, in-stream structures will

be installed to promote pool scour and glide and riffle formation while protecting adjacent banks.

The placement of hardened in-stream structures will provide grade control and protection for

infrastructure, while wooden structures will provide bank protection and habitat for target

species.




primary through the bedform diversity improvements, in-stream structures and the extensive

wetland areas.












Appendix L.

g. Project Area 7




Curve (McCandless and Everett, 2002). The most critical factor influencing the Piney Run

proposed channel dimensions is Piney Reservoir, upstream of the project area. The flow

operation of Piney Run Reservoir significantly reduces flood flows reaching the project area.

Thus, the proposed Piney Run channel cross sectional area is 45 sq. ft. versus 127 sq. ft. as

shown on the Piedmont Regional Curve. Additional supporting information describing how the

proposed cross sectional area was derived is presented in Section VIII.F.4-Hydrologic and

Hydraulic Analyses.



Since the elevation of the streambed cannot be increased due to infrastructure (i.e., Slacks Road

bridge crossing), the Service proposes excavation of a new floodplain. The elevation of the

floodplain is based on the historic floodplain analysis conducted by Dorothy Merritts, at Franklin

and Marshall College. It will be approximately one to two feet lower than the existing floodplain

elevation and extend to the valley toe-of-slopes on both sides of the stream. Excavating the

floodplain down to the historic floodplain elevations and out to the valley toe-of-slopes will

allow the Service to achieve the Level 2 - Hydraulic design goal of reconnecting to the historic

floodplain, maximizing valley width, and connecting flood flows of less than bankfull flows to

the floodplain. Furthermore, the proposed floodplain areas will consist of a wetland mosaic to

meet the Level 2 - Hydraulic design goal of increasing floodplain complexity and eliminating

concentrated flows.



would promote increased lateral stability. The proposed alignment was placed to take advantage

of the stability provided by the few large existing trees and to avoid potential conflicts with the

existing sewer line. To promote bed form diversity, in-stream structures will be installed to

promote pool scour, and glide and riffle formation while protecting adjacent banks. Additionally,

where feasible, the Service intercepted the historic gravel layer to promote bed stability and

increase hyporheic zone functions. While proper plan form is important, the Service has











wetland areas.









Appendix L.

h. Project Area 8

Project Area 8 is a continuation of the Piney Run mainstem and the design stream type for this

section continues the modified Rosgen C4 previously discussed in Project Area 7. However, a

significant portion of this project area is fully forested and instability problems are only localized

along short bank segments. Therefore, localized work was proposed to reduce significant impacts

to existing tree stands. This work includes the installation of three rock cross-vanes and toe wood

along outside meanders of unstable banks to promote bank stabilization. The design goals in

Level 3 – Geomorphology of lateral stability and sediment load reduction will be achieved

through the installation these in-stream structures. Furthermore, the installation of the rock cross-

vanes will promote pool scour, and glide and riffle formation to increase bedform diversity.

Areas adjacent to Project Area 8 consist of fully forested areas, as described in Section VI-Reach

Level Assessment. Construction will be extremely focused to limit removal of trees.

Additionally, reconnection of the floodplain with frequent inundation events will help promote

the development of forested wetlands.

i. Project Area 9

The proposed design stream type for Project Area 9 is a Rosgen B4. A Rosgen B4 stream type is

a non-meandering stream that dissipates energy vertically within the bed of the channel and has a

floodplain as small as 1.2 times its bankfull width. The most critical factor influencing the

Project Area 9 is the concrete culvert that conveys flows under MD Route 32. Years of

concentrated high volume flows have hampered the upstream portion of Project Area 9 and

severely eroded the banks. Along with historic incision, this has disconnected the reach from its

floodplain. The design aims to create a stream system that dissipates its energy vertically, rather

than laterally in order to minimize necessary floodplain width for stability.




Currently, the project area is disconnected from its floodplain and some floodplain needs to be

created to allow for adequate energy dissipation and to allow for more frequent out of bank flow

events. The Service proposes installing in-channel grade control structures along with light

excavation of a new floodplain, as well as some channel realignment. Doing so will allow the

Service to achieve the Level 2 - Hydraulic design goal of reconnecting the channel to an

available floodplain.


goals, the Service plans to slightly re-align the stream channel and install grade control structures

to promote increased lateral stability. To promote bedform diversity, in-stream structures will be

installed to promote pool scour, and glide and riffle formation while protecting adjacent banks.

While proper plan and profile form is important, the Service has recognized that stability cannot

be achieved without the proper riparian conditions. The Service has proposed dense upland

riparian plantings to increase the stability of the system.


through the bank stabilization and planting. Level 5 – Biology design objectives of increasing



Areas adjacent to Project Area 12 consist primarily of mixed hardwood upland areas of low

ecological value, as described in Section VI-Reach Level Assessment. Therefore, the only

potential adverse impacts, other than the ones described above in Section VIII.E.3.b-Potential

Adverse Impacts, are to 0.25 acres of existing, low ecological value mixed hardwood upland

areas that may be damaged from access. Impacts will be mitigated accordingly.

j. Project Area 10

Project area 10 will remain undisturbed with the exception of riparian planting along its banks

and into the adjacent uplands.

k. Project Area 11

Project area 11 only requires corrective actions in isolated areas of instability. The existing and

proposed design stream type for Project Area 11 is a Rosgen B4. A Rosgen B4 stream type is a

non-meandering stream that dissipates energy vertically within the bed of the channel and has a

floodplain as small as 1.4 times its bankfull width.

The Service has determined that Project Area 11 is generally stable and still connected to its

floodplain, so it does not require any additional action to meet the Level 2 – Hydraulic design

goal of floodplain reconnection/more frequent inundation.


and sediment load reduction design goals. The Service plans to address isolated instabilities

within the stream channel while maintaining existing plan form, profile and dimension. To

promote bedform diversity and lateral stability, in-stream structures will be installed to promote




pool scour and glide and riffle formation while protecting adjacent banks. While proper plan

form is important, the Service has recognized that stability cannot be achieved without the proper







Areas adjacent to Project Area 11 consist primarily of mature mixed hardwood forests, as

described in Section VI-Reach Level Assessment. Therefore, no adverse impacts, other than the

ones described above in Section VIII.E.3.b-Potential Adverse Impacts exist here.

l. Project Area 12

The proposed design stream type for Project Area 12 is a Rosgen B4c. Rosgen B4c stream type

is a non-meandering stream that dissipates energy vertically within the bed of the channel and

has a floodplain as small as 1.4 times its bankfull width.



The Service proposes lifting the channel bed, light excavation of a new floodplain, as well as

some channel realignment. Doing so will allow the Service to achieve the Level 2 - Hydraulic

design goal of reconnecting to the historic floodplain and maximizing valley width.



would promote increased lateral stability. The proposed alignment was placed to take advantage

of the stability provided by the few large existing trees. To promote bedform diversity, in-stream

structures will be installed to promote pool scour, and glide and riffle formation while protecting

adjacent banks. While proper plan form is important, the Service has recognized that stability

cannot be achieved without the proper riparian conditions. The Service has proposed dense

wetland riparian plantings that will extend beyond the limits of the design belt width to increase

the stability of the system.





wetland areas.

Areas adjacent to Project Area 12 consist primarily of mixed hardwood upland areas of low

ecological value, as described in Section VI-Reach Level Assessment. Therefore, the only

potential adverse impacts, other than the ones described above in Section VIII.E.3.b-Potential




Adverse Impacts, are to 0.25 acres of existing, low ecological value mixed hardwood upland

areas.

m. Project Area 13

Project Area 13 contains approximately 600 feet of small stream that drains a small spring seep.

No structures or channel work are proposed in the project area. Riparian planting along the banks

of the small spring seep channel will provide lateral stability through vegetation establishment

and help the service achieve Level 3 – Geomorphology design goals of increased riparian buffer.

Minor channel realignment at the downstream end of the channel will redirect flow into a

proposed wetland area to increase water retention time for improved sediment and nutrient

reduction before draining into the realigned UT6 channel. Changes to increase retention time and

alter the confluence along a more stable flow pattern will allow the Service to achieve additional

Level 3 – Geomorphology goals of increased sediment and nutrient retention and increased

lateral stability.

n. Project Area 14

Project Area 14 has two separate streams. There is the mainstem unnamed tributary (labeled as

UT6a Upper) and another unnamed stream (labeled UT6a1) that is a tributary toUT6a . The

proposed design stream type for UT6a is a Rosgen B4c. A Rosgen B4c has a steeper slope which

creates more energy, but less meander patterns that would be capable of dissipating that energy.

The project area runs through a confined valley which limits the possible meander width that

would allow the design to be a Rosgen C4 type stream. To compensate for this, several rock/log

j-hooks will be placed along the meander bends of UT6a in order to dissipate energy through the

developed scour pools. Along UT6a1, channel adjustments for bank repair and pool development

are only being made to a small section of the stream, approximately 50 feet in length. This

includes the installation of a constructed riffle with a cross vane to provide grade control.

Overall, the project area utilizes a Rosgen Priority Level 3 restoration approach, which involves

the excavation of a floodplain bench to promote floodplain inundation. The bank height ratio is

equal to 1 and the cross sectional area is slightly less than the regional curve prediction to help

promote the floodplain inundation and meet Level 2 – Hydraulics design goals.

Level 3 – Geomorphology increased bedform diversity design goals will be met through the

installation of in-stream structures and development of associated scour pools. The in-stream

structures will also improve lateral stability and provide reduced sediment loads by directing the

stream flow away from eroding banks. In addition, the Service has recognized that stability

cannot be achieved without the proper riparian conditions. The Service has proposed dense

wetland riparian plantings that will extend beyond the limits of the design belt width to increase

the stability of the system.





wetland areas.




Areas adjacent to Project Area 14 consist primarily of old fallow fields of low ecological value,

as described in Section VI-Reach Level Assessment. Furthermore, there are no existing

wetlands within Project Area 14.

o. Project Area 15

The proposed design stream types in Project Area 15 are made up of a Rosgen C4 (UT6a) and a

Rosgen B4c (UT6a2). DesigningUT6a as a C4 is made possible by widening the valley floor to

create sufficient room for a meander pattern typical of C4 streams. Restoration will involve a

Rosgen Priority 2 approach to create a floodplain bench at the historic floodplain bench elevation

and increase floodplain connectivity. UT6a2, a tributary to UT6a, will maintain its existing

alignment while sharp bends are smoothed out to address sediment sources. The channel bed in

UT6a2 will be raised, following a Rosgen Priority 1 Restoration Approach. Channel dimensions

across both tributaries in this project area will also be designed to be slightly smaller than the

regional curve prediction in order to promote more frequent floodplain access. These two

approaches in each stream channel will promote more frequent floodplain access and meet Level

2 – Hydraulic design goals of increased floodplain connectivity.

Level 3 – Geomorphology design goals for increased bedform diversity are met through the

installation of in-stream rock and wood structures that promote development of associated scour

pools. The B4c stream (UT6a2) will require stream structures to be placed frequently to promote

the development of scour pools to help regulate energy dissipation in the steeper B4c type

stream. Also, the hardened in-stream structures will improve lateral stability to protect

infrastructure and provide grade control for vertical stability. This combined with wooden

structures, such as toe wood, along actively eroding banks will ensure that the design goals of

reducing sediment loads and providing habitat are met. In addition, the Service has recognized

that stability cannot be achieved without the proper riparian conditions. The Service has

proposed dense wetland riparian plantings that will extend beyond the limits of the design belt

width to increase the stability of the system.


through the bank stabilization and the creation of extensive wetland areas. Level 5 – Biology

design objectives of increasing macroinvertebrate and fish population diversity and densities will

be met primarily through the bedform diversity improvements, in-stream structures, and the

extensive wetland areas.




acres of existing, low ecological value wetland areas. The impacts to these existing wetlands will

be self-mitigating through the creation of new wetland areas that significantly exceed the

existing wetland area in acres and ecological value. Details of wetland creation are presented in

Section VII-Wetland Assessment. Exact figures and locations of wetland impacts are referenced

in Section IX-Impacts to Existing Resources and Appendix L.




p. Project Area 16

Project Area 16 is comprised of four unnamed tributaries to the Piney Run mainstem that help

form an extensive wetland complex in the forested area. UT7, UT8 and UT8a are made up of

small grass channels that move across the Piney Run floodplain, while UT9 has a slightly higher

grade and confinement from the valley it sits in. The upstream portion of UT7 will have five

berms installed to establish a regenerative storm conveyance (RSC) system and help promote

sediment retention. Work on the downstream end of UT7 will then primarily focus on the

installation of log steps and constructed riffles to provide stability and in-stream habitat. The

UT8, UT8a, and UT9 tributaries will have limited work done on them except stabilization near

the confluence with the Piney Run mainstem.

To achieve the Level 3 – Geomorphology lateral stability and bedform diversity design goals, the

Service has planned for the limited installation of constructed riffles and log drops. Log drops

will promote the subsequent development of associated scour pools to increase bedform

diversity. The RSC in UT7 will help meet reduction and trapping of sediment design goals by

retaining water for longer periods of time. Overall, the Project Area will see minimal channel

work except for the installation of log drops and constructed riffles to help establish stable

environments around the confluences with the mainstem of Piney Run.

Areas adjacent to Project Area 16 consist primarily of forested wetland, as described in Section

VI-Reach Level Assessment. The establishment of the RSC and reconnection of the floodplain

to the stream will provide more frequent flood inundations of parts of these areas to provide

enhancement of wetland areas. Therefore, any impact to existing wetlands will be self-

mitigating through the enhancement of wetland areas that will improve the ecological value.

Details of wetland impacts and creation are presented in Section VII-Wetland Assessment.

3. In-stream Structures

Rock and log structures are in-stream structures, made of natural materials, used to divert erosive

stream flows away from stream banks and maintain streambed elevations. The most typical rock

and log structures used in stream restoration are cross-vanes, j-hooks, log-rollers and toe wood.

The rock and log structures provide streambed and bank stability and allow the streambed to

naturally armor and the riparian vegetation to establish.

The Service has determined that cross-vanes are only required at utility crossings to maintain

grade and the rest of the project area will utilize toe wood and wood j-hook structures to promote

stability and increase aquatic habitat. The locations of these structures were determined by

matching the naturally occurring pool-to-pool spacing and strategically placing them in areas that

would exhibit higher shear stress values during high flow events.

a. Cross Vane

The cross-vane (Figure 11) will establish grade control, reduce bank erosion, create a stable

width/depth ratio, and maintain channel capacity, while maintaining sediment transport capacity,

and sediment competence. The cross-vane also provides for the proper natural conditions of




secondary circulation patterns commensurate with channel pattern, but with high velocity

gradients and boundary stress shifted from the near-bank region. The cross-vane is also a stream

habitat improvement structure due to: 1) an increase in bank cover as a result of a differential

raise of the water surface in the bank region; 2) the creation of holding and refuge cover during

both high and low flow periods in the deep pool; 3) the development of feeding lanes in the flow

separation zones (the interface between fast and slow water) due to the strong down welling and

upwelling forces in the center of the channel; and 4) the creation of spawning habitat in the tail-

out or glide portion of the pool (Rosgen, D.L., 2001). While the figure below shows a structure

consisting of large boulders, the cross-vane can be constructed using other materials such as logs

and rootwads.

Figure 11: Cross Vane in Plan View

b. J-Hook

The j-hook vane is an upstream directed, gently sloping structure composed of natural materials.

The structure can include a combination of boulders, logs and root wads, (Figure 12) and is

located on the outside of stream bends where strong down welling and upwelling currents, high

boundary stress, and high velocity gradients generate high stress in the near-bank region. The

structure is designed to reduce bank erosion by reducing near-bank slope, velocity, velocity

gradient, stream power, and shear stress. Redirection of the secondary cells from the near-bank

region does not cause erosion due to back-eddy re-circulation. The vane portion of the structure

occupies 1/3 of the bankfull width of the channel, while the hook occupies the center 1/3 as

shown in Figure 12 (Rosgen D.L., 2001).

Maximum velocity, shear stress, stream power, and velocity gradients are decreased in the near-

bank region and instead redirected towards the center of the channel. Sediment transport

competence and capacity can be maintained as a result of the increased shear stress and stream




power in the center of the channel. Backwater is created only in the near-bank region, reducing

active bank erosion (Rosgen D. L., 2001). While the figure below shows a structure consisting of

large boulders, the j-hook vane can be constructed using other materials such as logs and root

wads.

Figure 12: J-Hook Vane in Plan View

c. Log Drop Structure

The log roller structure is an alternative to hardened riffles. These structures act as a grade

control, but instead of holding the grade of a glide feature, they instead hold the grade of the top

of riffle feature. The log roller consists of alternatively angled and sloped logs that are placed at

low grades in an effort to “roll” water back and forth while still concentrating energy towards the

center of the channel. The structure is typically used in straight portions of the channel as they

are effective in generating aeration and increased dissolved oxygen concentration by creating

hydraulic rises and falls while still directing stream energy towards the center of the channel.

These structures also add woody debris into the stream system promoting increased habitat for

aquatic species. Figure 13 shows a typical drawing for a log drop structure.




Figure 13: Log Drop Structure

d. Toe Wood

The toe wood structure (Figure 14) incorporates native woody material into a submerged

undercut bank to replicate natural stream banks. Toe wood is positioned on the lower 1/3 to 1/2

of bankfull height to ensure it is submerged year round to prevent wood deterioration. Cuttings

with sod and live staking or woody transplants cover the toe wood and are installed up to the

bankfull stage. Not only does toe wood act as an area of increased roughness which promotes

reduction in shear stresses to the outside of the meander, it also serves as a haven for benthic

macroinvertebrates and fish communities.

Figure 14: Toe Wood




e. Oxbow/Vernal Pool Features

Oxbow lakes (Figure 15) are formed when river erosion wears through the bank between two

consecutive bends. Most water travels through the new channel, and the old bend is cut out, with

water only passing through it very slowly. This slow speed causes sediment that is suspended in

the river water to settle on the old bend's riverbed. Eventually, enough sediment settles in the old

bend to close it off from the new channel and an oxbow lake is formed (DK Books, Lake

Formation).

The Service utilizes abandoned sections of the original stream alignment to create oxbow

features in the Piney Run design for a variety of reasons. The introduction of these discontinuous

oxbow pool features provides additional rearing habitat for fish species as well as excellent

refuge for other aquatic species. Beavers are also naturally drawn to these areas and they serve as

a preferred location for dens and dams. This prevents beavers from impacting or influencing

channel flow and minimizes the threat of beaver-related damming and ponding of the restored

stream reach.

Figure 15: Oxbow Creation

f. Rock/Log Deflector

The Rock/Log Deflector (Figure 16) is an upstream directed, gently sloping structure composed

of natural materials. The structure can include a combination of boulders, logs and root wads and

is located on the outside of stream bends. The structure is designed to reduce bank erosion by

reducing near-bank slope, velocity, velocity gradient, stream power and shear stress. The

structure occupies 1/3 of the bankfull width of the channel.




Maximum velocity, shear stress, stream power and velocity gradients are decreased in the near-

bank region and increased in the center of the channel. Sediment transport competence and

capacity can be maintained as a result of the increased shear stress and stream power in the

center of the channel. Backwater is created only in the near-bank region, reducing active bank

erosion (Rosgen D. L., 2001).

Figure 16: Rock Deflector in Plan View

g. Constructed Riffle

Constructed Riffles (Figure 17) are installed to provide immediate grade control for the project

area using stone as a substrate. These structures remain stable while the pavement and sub-

pavement layers develop in the restored stream providing long term grade control. The stone in

the constructed riffle shall be placed in such a way as to mimic the action of a natural riffle by

producing turbulent flow.

Figure 17: Constructed Riffle in Plan View




h. Rock Step

Rock Steps (Figure 18) are in-stream structures installed at the downstream end of a riffle to

provide grade control for the riffle while the pavement and sub-pavement layers develop

providing long term grade control. They consist of a row of foot and header rocks with filter

fabric placed on the upstream side of the structure. The elevation of the top footer rocks is equal

to the stream bed.

Figure 18: Rock Step in Plan View

i. Step Pool Channel

Step Pool Channels (Figure 19) provide grade control in areas of high slope or when a large

grade change is needed, but limited by stream length. They consist of a rock step constructed

with header and footer rocks for grade control. Pools are constructed between the steps with

smaller stones to provide energy dissipation. The pool to pool spacing gets smaller as the slope

increases.

Figure 19: Step Pool Channel in Plan View




j. Stacked Rock Wall

Stacked Rock Walls (Figure 20) consist of large boulders with at least 2 parallel flat surfaces are

placed in rows along a bank to prevent bank erosion. Footer stones are buried below the invert

of the channel to protect from toe scour. Additional boulders are stacked on top to reached the

desired elevation. Rocks in the wall should be touching on the stream side to minimize voids

between the rocks. Filter fabric is placed behind the wall and the area is back filled with stone to

seal the voids between the boulders.

Figure 20: Stacked Rock Wall in Plan View

k. Grade Control Woody Riffle

Grade Control Woody Riffles (Figure 21) are a variation of a constructed riffle that primarily

uses logs and woody debris instead of rock as the substrate to provide grade control. The

upstream and downstream end are constructed with header and footer logs, while channel in

between is filled with layers of smaller logs and woody debris. During construction, the voids

between the woody debris are backfilled with sand and gravel.

Figure 21: Grade Control Woody Riffle in Plan View




l. Ford Stream Crossing

Ford stream crossings (Figure 22) are used as an alternative to culverts or bridges on lightly

travelled roads. They limit the impact to the channel cross section and don’t constrict or reduce

channel capacity during high flow events. The crossing is installed at a right angle to stream

flow and is armored with stone to prevent the channel from being disturbed by vehicle traffic.

Figure 22: Ford Stream Crossing Structure

m. Rock Toe

A Rock Toe (Figure 23) consists of a line of large rocks along the toe of the stream bank

designed to prevent bank erosion. Approximately ½ of the rock is placed below the invert of the

stream to protect the bank from toe scour. After installation of the rock, a soil lift is constructed

on top of the line of rocks to the bankfull elevation and allows establishment of vegetation along

the bank.

Figure 23: Rock Toe Structure

n. Swale with Ditch Plugs

These structures consist of a series of cobble weirs with a consolidated clay base. The purpose

of the ditch plugs is to prevent erosion of the swales during runoff events. With the clay base,

runoff is retained in the pools upstream of the cobble weirs. This creates a pool on the upstream




side of the structure; creating pool habitat, water storage and causing infiltration. The intent of

the structures is to provide both a water quantity and a water quality improvement through the

retention and infiltration of the runoff. A typical swale with ditch plugs is shown in Figure 24.

Figure 24: Swale with Ditch Plugs in Plan View

4. Hydrologic and Hydraulic Analyses

Evaluating the hydraulics of a stream system is an important component to any assessment

because it gives a better understanding of how water and sediment are transported through the

channel and its associated floodplain. Since one of the design approaches used for this project

was NCD, bankfull validation was required before conducting the hydraulic analysis. Detailed

results of the hydrology and hydraulic assessment can be found in Appendices K – Velocity

Calculations and L - HEC-RAS: Existing and Proposed.

a. Bankfull Verification

Bankfull discharge characterizes the range of discharges that is effective in shaping and

maintaining a stream. Over time, geomorphic processes adjust the stream capacity and shape to

accommodate the bankfull discharge within the stream. Bankfull discharge is strongly correlated

to many important stream morphological features (e.g., bankfull width, drainage area, etc.) and is

a critical piece of data used for several assessment parameters. Bankfull discharge is also used in

natural channel design procedures as a scale factor to convert morphological parameters from a

stable reach of one size to a disturbed reach of another size. The Service used Regional

Relationships as well as Resistance Relationships to determine the bankfull discharge and

channel dimension at the Big Cove Creek.

i. Geomorphic Indicators

During the Piney assessment, the Service identified bankfull stage using geomorphic indicators

formed by the stream as described by McCandless (2003). Figure 25 depicts significant

geomorphic indicators typically found in the Mid-Atlantic. Based on these indicators, the




Service identified a consistent geomorphic feature at the Piney Run. This geomorphic indicator

was typically a significant slope break or back of bench found throughout the project area. A

stable riffle was located within the project and surveyed to calculate stable channel dimensions

(i.e., width, depth, and area) associated with this geomorphic indicator. The riffle cross section

dimensions were then compared to the regional curves in the Bankfull Discharge and Channel

Characteristics of Stream in the Piedmont Hydrologic Region (McCandless and Everett, 2002).

Details of this comparison are described below in Section VIII.F.4.a.iii-Resistance Relationships.

Figure 25: Typical Bankfull Indicators (McCandless, 2003)

ii. Regional Relationships

The regional curve estimates channel discharge based on a linear regression equation derived

from gaged sites across the same physiographic region with similar characteristics. Using only

the drainage area, the Service was able to derive the estimated channel width, depth, cross

sectional area and discharge using the Bankfull Discharge and Channel Characteristics in the

Piedmont Hydrologic Regions regional curve (McCandless and Everett, 2002) (Table 16). This

information was then compared to the field measured riffle cross section to validate bankfull

dimension and discharge.

iii. Resistance Relationships

There are several methods to estimate bankfull discharge and velocity using resistance

relationships. These methods typically make use of the cross sectional area, flow depth,

representative particle size of channel substrate, channel slope, and a determined roughness

coefficient, or “friction factor”. The Service used the Roughness Coefficient equation to

determine discharge. This equation, 𝒖 = 𝟏. 𝟒𝟗 ∗ 𝑹𝟐 𝟑⁄ ∗ 𝑺𝟏 𝟐⁄ /𝒏, uses the hydraulic radius of the

representative cross section, the channel slope, and a known Manning’s n (based on stream type)

to determine velocity and discharge values. This method closely matched the back calculated

roughness coefficient and was in agreement with the regional relationship findings and proved to

be an appropriate estimate for bankfull discharge for all Project Areas except for Project Area 7 –

Piney mainstem. Project Area 7 channel dimensions are significantly less than the region curve




channel dimensions because of Piney Run Reservoir, located approximately 2 miles upstream of

the project area. Piney Run Reservoir significantly affects the flow regime for Project Area 7

and as well as Project Area 8, which is downstream of Project Area 7. A discharge analysis,

using HEC-HMS, determined that the hydrograph influencing Project Areas 7 and 8 is primarily

influenced by the drainage area downstream of the reservoir versus the entire watershed drainage

area. This is because maximum flow releases from Piney Reservoir do not exceed flows greater

than a 1 year storm event. Therefore, Project Areas 7 and 8 have flow discharges and channel

dimension characteristics associated with the drainage area downstream of the reservoir, which is

4.6 square miles versus the 15.2 square miles associated with the entire watershed. This

constraint will significantly influence design channel dimensions, specifically a smaller channel

then what would be expected for a project drainage area of 15.2 square miles. In fact, the

regional curve bankfull channel dimensions associated with a 4.6 square miles are: Area – 53

square feet, Width – 27 feet, Depth – 2.0 feet and Discharge – 270 cubic feet per second. These

channel dimensions compare well to the reference riffle channel dimensions, further supporting

the significant influence of Piney Run Reservoir.

The design channel dimensions for Project Areas 5 and 6 are slightly less than the reference riffle

and regional curve channel dimensions. The Service intentionally set smaller design channel

dimensions in order to inundate the floodplain more frequently. Given that the upstream

sediment supply is low and that the design channel dimensions are not smaller than the reference

riffle dimensions, the proposed channel dimension should be self-sustaining over time.

A summary of bankfull discharges and velocities can be found in Table 16 and detailed

information can be found on the “Proposed Design Conditions Plan Set Computations of

Velocity and Bankfull Discharge Using Various Methods” worksheet in Appendix I – Velocity

Calculations.

Design and Regional Curve Bankfull Characteristics –

Project Area 3: DA= 1.23 mi2

Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 25 20.5 21.1 -

Width (ft) 18 17.0 16.4 -

Depth (ft) 1.4 1.3 1.3 -

Velocity (ft/s) 3.78 - 3.92 3.1 4.9 -

Discharge (cfs) 95 - 99 62 103.0 102 / 138

Characteristics in the Piedmont Hydrologic regional curves (McCandless and Everett 2002)






Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 25 22.0 22.0 -

Width (ft) 18 17.0 16.8 -

Depth (ft) 1.4 1.4 1.3 -

Velocity (ft/s) 3.78 - 3.92 3.6 4.9 -

Discharge (cfs) 95 - 99 99 108.0 110 / 148




Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 32 25.0 31.0 -

Width (ft) 15 19.3 20.1 -

Depth (ft) 2.1 1.3 1.54 -

Velocity (ft/s) 5.28 – 5.36 3.2 5.0 -

Discharge (cfs) 166 - 170 99 154.0 170 / 226




Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 32 25.0 31.4 -

Width (ft) 15 19.3 20.2 -

Depth (ft) 2.1 1.3 1.6 -

Velocity (ft/s) 5.28 – 5.36 2.8 5.0 -

Discharge (cfs) 166 - 170 166 156.1 173 / 229







Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 52 45.0 125.2 -

Width (ft) 35 25.8 42.4 -

Depth (ft) 1.5 1.8 3.0 -

Velocity (ft/s) 3.30 - 3.50 2.5 5.3 -

Discharge (cfs) 177 - 182 176 658.9 635 / 835




Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) - 6.0 4.4 -

Width (ft) - 8.5 7.1 -

Depth (ft) - 0.7 0.6 -

Velocity (ft/s) - 2.9 4.6 -

Discharge (cfs) - 9 20.0 17.2 / 24.5




Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 11 12.0 9.1 -

Width (ft) 10 12.0 10.4 -

Depth (ft) 1.1 1.0 0.9 -

Velocity (ft/s) 3.41 - 3.71 3.5 4.7 -

Discharge (cfs) 37 - 40 37 42.9 55.2 / 73.2







Bankfull

Characteristics

Reference Cross

Section

Design Cross

Section

Regional

Curve (2005)

USGS

StreamStats

1.25 / 1.5 RI

Area (sq. ft) 11 12.0 14.1 -

Width (ft) 10 12.0 13.2 -

Depth (ft) 1.1 1.0 1.1 -

Velocity (ft/s) 3.41 - 3.71 3.2 4.8 -

Discharge (cfs) 37 - 40 37 68.0 89 / 117


Table 16: Design and Regional Curve Bankfull Characteristics

iv. Bankfull Validation

The bankfull discharges range between 9 to 176 cubic feet per second (cfs) since there are

numerous project areas with differing drainage areas. However, the discharges generally

correspond well with the regional curve, with exception of Project Area 7 – Piney Run because

of the flow restrictions associated with Piney Reservoir, which was discussed in Section

VIII.F.2.g-Project Area 7. More important is how closely the surveyed cross section channel

dimensions correspond with the regional curve. Estimating discharge has a higher range of error

due to the sensitivity of the factors used in calculating discharge. Measurement of cross section

area is more precise and a better indicator for validating bankfull flow. However, it should be

noted that most of the proposed design cross dimensions are slightly less than the regional curve

data. This was intentional by the design team to better meet the frequent floodplain inundation

design objective. By designing a channel slightly smaller than the regional curve dimensions,

the floodplain can be accessed more frequently by flood flows. Furthermore, channel aggradation

should not be a problem since the sediment supplies are mostly low and the proposed design

channel dimensions can transport what is being delivered, which is described below in Sections

VIII.F.4.c-Sediment Analysis.

b. Hydrologic and Hydraulic Assessment

The Service used the HEC-RAS model to test stream channel and floodplain stability of the

proposed design. HEC-RAS model runs were completed for only those project areas that

involved significant channel modifications: Project Areas 3, 4, 5, 6, 7, 9, 14, and 15. All other

project areas only had minimal and localized restoration activities that would not significantly

alter stream hydrology and hydraulics. Detailed results of the hydraulic assessment can be found

in Appendix J - HEC-RAS: Existing and Proposed.




The HEC-RAS model was run using bankfull discharges and flood discharges for each as shown

above in Table 16: Design and Regional Curve Bankfull Characteristics. These flows were

derived from the resistance relationship using existing and design channel and valley geometry.

A Manning’s roughness coefficient of 0.029 to 0.036 was used for in-channel roughness, which

is common among low to moderate gradient streams and an overbank roughness of 0.045 was

used as a worst-case scenario, lightly vegetated roughness. The HEC-RAS model run showed

that proposed flows would have channel velocities at bankfull stage ranging between 1.52 and

5.67 ft/s with the majority of them around 2.5 to 4.5 ft/s and shear stresses ranging between 0.13

and 2.30 ft/s with the majority of them around 0.25 to 1.70 ft/s (Table 17). The proposed shear

stresses and velocities are typical of a project this size and less than all the existing stream

energy conditions except for Project Area 5. Project Area 5 has a maximum proposed velocity

of 5.67 ft/s and is not considered to be high enough to result in stream degradation. Additionally,

lateral and vertical control structures are used throughout this reach to further reduce risk of any

degradation.




Piney Run- HEC-RAS Model Results

Bankfull

Characteristics

Storm

Event

Existing

Conditions

Channel Shear

Stress (lbs/ft2)

Design

Conditions

Channel Shear

Stress (lbs/ft2)

Existing

Conditions

Channel

Velocity (ft/s)

Design

Conditions

Channel

Velocity (ft/s)

Existing

Conditions

Water Elevation

(ft)

Proposed

Conditions

Water Elevation

(ft)

Project Reach

3

Bankfull 0.32 - 2.02 0.23 - 1.88 2.25 - 5.12 1.89- 4.96 450.15-458.74 451.32-459.30

2 year 0.45 - 1.72 0.35 - 1.52 2.75 - 4.97 2.43 - 4.92 450.95-459.46 451.88-460.03

10 year 0.85 - 2.27 0.61 - 2.21 4.12 - 6.71 3.40 - 6.42 452.39-460.90 452.73-461.08

50 year 0.96 - 2.68 1.19 - 2.82 4.63 - 7.69 4.97 - 7.61 453.58-461.82 453.61-461.95

100 year 1.29 - 2.90 1.41 - 2.88 5.43 - 8.12 5.51 - 7.80 454.08-462.21 454.04-462.35

Project Reach

4

Bankfull 0.31 - 2.53 0.52 - 1.65 2.31 – 6.00 2.80 - 4.78 434.95-448.80 434.34-450.86

2 year 0.54 - 2.76 0.57 - 2.86 3.20 - 6.67 3.07 - 6.93 435.60-449.65 434.96-451.31

10 year 0.48 - 3.32 0.91 - 2.68 3.32 - 8.52 4.16 - 7.45 436.69-451.09 435.93-452.17

50 year 1.10 - 3.96 1.24 - 5.83 5.16 - 9.65 5.17 - 11.28 438.01-452.48 437.05-452.98

100 year 1.26 - 4.70 1.38 - 4.45 5.58 - 10.63 5.53 - 10.18 438.55-452.94 437.62-453.38

Project Reach

5

Bankfull 0.18 - 0.92 0.40 - 2.30 1.84 - 3.44 1.83 - 5.67 428.46-433.48 426.92-433.00

2 year 0.33 - 1.55 0.45 - 2.18 2.59 - 4.65 2.05 - 5.90 429.21-434.27 427.64-433.54

10 year 0.48 - 2.31 0.55 - 3.17 3.37 - 6.3 2.90 - 7.77 430.89-435.64 428.76-434.57

50 year 0.40 - 3.53 0.69 - 2.09 3.18 - 8.57 3.59 - 6.83 432.97-437.09 431.10-435.72

100 year 0.32 - 3.91 0.54 - 2.38 2.91 - 9.23 3.58 - 7.43 434.21-437.67 432.48-436.26

Project Reach

6

Bankfull 0.25 - 1.44 0.13 - 1.51 2.16 - 5.23 1.52 - 4.96 419.92-427.10 418.60-426.26

2 year 0.19 - 2.30 0.09 - 1.74 1.94 - 6.71 1.24 - 5.33 420.72-427.79 418.89-426.83

10 year 0.34 - 2.52 0.31 - 2.82 2.70 - 7.23 2.39 - 6.97 421.72-429.14 419.61-427.77

50 year 0.46 - 2.74 0.47 - 4.24 3.20 - 7.93 3.13 - 8.83 422.39-430.00 420.42-428.54

100 year 0.52 - 2.91 0.51 - 3.63 3.46 - 8.25 3.48 - 8.39 422.67-430.35 420.82-429.07




Bankfull

Characteristics

Storm

Event

Existing

Conditions

Channel Shear

Stress (lbs/ft2)

Design

Conditions

Channel Shear

Stress (lbs/ft2)

Existing

Conditions

Channel

Velocity (ft/s)

Design

Conditions

Channel

Velocity (ft/s)

Existing

Conditions

Water Elevation

(ft)

Proposed

Conditions

Water Elevation

(ft)

Project Reach

7

Bankfull 0.09 - 2.35 0.09 - 1.14 1.36 - 6.11 1.36 - 4.28 413.06-420.05 413.06-419.9

2 year 0.22 - 2.73 0.11 - 1.78 2.29 - 7.56 1.61 - 5.92 416.63-422.19 416.61-421.51

10 year 0.30 - 1.40 0.19 - 1.55 2.83 - 5.93 2.27 - 6.08 419.01-423.72 418.98-422.80

50 year 0.41 - 1.69 0.26 - 1.51 3.49 - 6.70 2.78 - 6.29 421.42-425.11 421.40-424.14

100 year 0.36 - 1.47 0.26 - 1.27 3.33 - 6.4 2.85 - 5.91 422.9-425.76 422.89-424.97

Project Reach

9

Bankfull 0.25 - 1.33 0.48 - 1.32 1.56 - 3.76 2.33 - 3.72 522.14-538.36 522.72-539.88

2 year 0.31 - 1.71 0.63 - 1.69 1.85 - 4.46 2.78 - 4.46 522.33-538.56 523.01-540.10

10 year 0.61 - 2.45 1.20 - 2.76 2.97 - 5.92 4.27 - 6.43 522.85-539.15 523.62-540.68

50 year 1.08 - 2.85 1.86 - 3.06 4.19 - 7.00 5.73 - 7.27 523.53-539.81 524.40-541.25

100 year 1.37 - 3.15 2.20 - 3.68 4.84 - 7.58 6.43 - 8.17 523.85-540.10 524.80-541.56

Project Reach

14

Bankfull 0.38 - 2.94 0.53 - 1.93 1.50 - 4.13 2.54 - 4.95 456.13-465.95 456.14-465.64

2 year 0.76 - 3.06 0.90 - 2.14 2.42 - 4.95 3.98 - 5.96 457.76-467.13 457.12-466.84

10 year 1.04 - 4.02 1.10 - 4.20 3.07 - 6.15 4.78 - 8.91 458.95-468.40 458.23-468.16

50 year 1.51 - 5.74 1.42 - 4.46 3.86 - 7.70 5.74 - 9.80 459.72-469.74 459.25-469.52

100 year 1.81 - 6.97 1.76 - 4.54 4.30 - 8.65 6.50 - 10.11 460.03-470.29 459.64-469.97

Project Reach

15

Bankfull 0.21 - 4.83 0.27 - 1.79 1.79 - 5.27 1.91 - 4.69 434.72-453.25 435.36-453.18

2 year 0.58 - 3.17 0.47 - 2.25 3.29 - 7.11 2.79 - 6.02 436.01-454.88 436.02-454.12

10 year 1.30 - 7.12 0.92 - 4.07 5.28 - 8.33 4.11 - 8.82 437.01-455.83 436.66-455.17

50 year 1.44 - 5.17 1.40 - 5.73 5.79 - 9.91 5.24 - 11.15 437.87-457.42 437.38-456.35

100 year 1.53 - 5.90 1.56 - 4.98 6.03 - 10.86 5.64 - 9.98 438.35-457.70 437.73-457.64

Table 17: HEC-RAS Model Results




c. Sediment Analysis

The objective of sediment transportation for the project is to design Piney Run and its tributaries

to maintain the competency to entrain the largest measured particle size of the bar sample

determined by the sieve analysis conducted by the Service. As noted previously, a sediment

analysis was done at individual project areas representing larger reaches that would undergo

restoration that would modify plan, profile and dimension. Those areas that were not being

reconfigured were not analyzed due to the fact that competency was not perceived to be an issue.

Initial competency findings showed that Piney Run did not have the required depth to initiate

movement of the largest measured particle size (49mm) of the bar sample. This is further

supported by field observed deposition patterns which included some mid-channel bar formation

as well as lateral bars. While these deposition formations are isolated, they do indicate a

reduction in sediment competency related to a shallowing condition that is a result of channel

widening. The Service aims to reduce channel width, cross sectional area, and increase mean

depth to increase the channel’s sediment transport competency. The increased depth meets the

required depth as shown by Rosgen’s power trend line on Shields critical shear stress

relationship. The predicted particle size that can be moved is 64 mm which is just slightly larger

than the largest particle size (49 mm) collected in the bar sample, but smaller than the riffle

d100. This ensures the channel will not degrade over time.

Competency findings showed that the lower portion of UT6 was competent and able to initiate

movement of the largest particle size found of the bar sample. This is further supported by no

major observed deposition patterns which would indicate excessive aggradation. The Service

will maintain similar geometric configuration of the channel, stabilize lateral erosion issues, and

also allow the channel to access its floodplain once more. Additionally, since stream length is

being reduced, slope will increase slightly. The design depth meets the required depth as shown

by Rosgen’s power trend line on Shields critical shear stress relationship. The predicted particle

size that can be moved is 64 mm which is just slightly larger than the largest particle size (50

mm) collected in the bar sample, but smaller than the riffle d100. This ensures the channel will

not degrade over time.

Similar to Piney Run, competency findings for the lower portion of UT6 showed that there was

not quite enough depth to initiate movement of the largest measured particle size of the bar

sample. In this area, the Service aims to reduce the channels cross sectional area as much as

possible while still maintaining a competent configuration. The channel dimensions will meet the

required dimensions as shown by Rosgen’s power trend line on Shields critical shear stress

relationship. The predicted particle size that can be moved is 73mm which is just slightly smaller

than the largest particle size (90 mm) collected in the bar sample, this ensures the channel will

not degrade over time.

Competency findings showed that the lower portion of UT6a were competent and able to initiate

movement of the largest particle size found on the point bar. This is further supported by no

major observed deposition patterns which would indicate excessive aggradation. The Service

will maintain similar geometric configuration of the channel, stabilize lateral erosion issues, and




also allow the channel to access its floodplain once more. The design depth meets the required

depth as shown by Rosgen’s power trend line on Shields critical shear stress relationship. The

predicted particle size that can be moved is 95 mm which is just slightly larger than the largest

particle size (84 mm) collected in the bar sample, but smaller than the riffle d100. This ensures

the channel will not degrade over time.

The main stability problems within Piney Run and its tributaries are mostly related to lateral

instability problem (e.g., widespread bank erosion). A sediment capacity analysis was not

conducted since Piney Run and its tributaries do not appear to have a significant aggradation or

degradation stability problem. Table 18 summarizes the Service’s findings and detailed

information can be found in Appendix C.

Sediment Transport Competency

Representative

Reach Parameter

Measurement

Method

Restoration Condition

Design Required

Piney Main

Sediment

Transport

Competency

Required Depth 1.80 1.70

Required Slope 0.004 0.004

UT6 Middle

Sediment

Transport

Competency



UT6 Lower

Sediment

Transport

Competency



UT6a

Sediment

Transport

Competency



Table 18: Sediment Transport Capacity for Representative Reaches

5. Vegetation Design

The riparian buffer is an integral part of the stream ecosystem, providing bank stability and

nutrient uptake, serving as a food source for aquatic organisms downstream of the project area,

and providing terrestrial habitat and migration corridors for wildlife. Many species of wildlife

will benefit including migratory birds, amphibians, reptiles, small mammals, and pollinating

insects. Shading from the buffer will moderate stream temperature and prevent excessive algal

growth. The riparian vegetation will help increase infiltration and evapotranspiration, which will

benefit stream base flow in lower stream sections and help reduce erosive velocities of runoff.

Large woody debris derived from the buffer is an important component of aquatic habitat.

The riparian planting has five distinct zones; stream banks, riparian vegetation, forested

wetlands, emergent wetlands and uplands. Zone 1 – Streambank planting will include installation

of live stakes along all disturbed stream banks to help provide early stabilization of banks with

vegetation establishment. Next, Zone 2 – Riparian Planting will include a combination of trees

and shrubs along either bank where restoration work takes place. The riparian planting zone will




extend into the excavated floodplain from the top of bank and will not follow the sinuosity of the

stream channel. This will help ensure vegetation is established across the full floodplain width to

help provide stability during large flood flows. Zone 3 – Forested Wetlands will include a

mixture of trees and shrubs specific for forested wetland development. Areas that will be

developed for forested wetland include where the existing channel will be abandoned during

channel realignment in several project areas and the subsequent creation of oxbow pools. There

is also extensive establishment of forested wetlands in the floodplain of Project Area 3. Zone 4 –

Emergent Wetlands will use a combination of shrubs to establish vegetation. Emergent uplands

will be established in Project Area 6 and near the confluence of UT6 with Piney Run in Project

Area 7. Zone 5 – Upland planting will take place as a further buffer beyond the Zone 2 –

Riparian Planting. It will extend, where practical, to the toe of slope along the floodplain of the

project areas where significant channel work is done.

Overall planting densities of trees and shrubs combined across all zones will be 303 stems per

acre (12’ x 12’ spacing. Live stakes in Zone 1 will be placed as a single row with three-foot

spacing. Seed mix will be applied to Zones 1 – 4 at a rate of 20 lbs/acre and Zone 5 will have

permanent seed mix applied at a rate of 10 lbs/acre. Temporary seed mix will be applied to all

disturbed areas as construction progresses. The detailed planting plan can be found in Appendix

K.

IX. IMPACTS TO EXISTING RESOURCES

There are a variety of ecologically valuable resources throughout the project areas that the

Service took great care in observing, avoiding, and maintaining during the design phase.

However, in some cases impacts to these sensitive areas were unavoidable and necessary for the

success of the overall project.

Piney Run, UT6, and UT6e stream lengths were reduced / impacted in order to achieve a more

stable configuration. Since the restoration configuration resulted in reduced stream length, the

impacts to resources had to reflect the reduction. However, while the net change is negative, the

stability, habitat value, and overall function of the stream will improve.

Wetlands found adjacent to the stream channels were also impacted in various ways, both

permanently and temporarily. Permanent impacts came as a result of channel realignment, where

the old channel was abandoned for a more desirable configuration. In which case, the new

configuration may meander into an existing wetland buffer or wetland. Typically, these impacts

are mitigated almost instantly, since the abandoned channel is designed to be converted into a

similar type wetland resulting in a net change of zero. Temporary impacts include those areas

where the resource would be reverted back to its original condition post impact. These areas

were generated as a result of temporary construction haul roads and crossings necessary to

implement the restoration project. Collectively, with the restoration also creating additional

wetland features, the project shows a substantial net gain.

Temporary and permanent impacts to perennial open water (POW) stream areas as well as

palustrine emergent wetlands (PEM) were identified and tabulated and are shown in detail in




Table 19 below. Additionally, impact figures and net change information can be seen in

APPENDIX L.

Aquatic Resource Name

1

Existing Resource

Class Activity

Impact Duration

Impact Area

(square ft)

Impact Length

(linear ft)

Proposed resource class

post-construction

Piney Run Per Realignment / Fill Permanent 21,982 852 Floodplain

UT6 Per Realignment / Fill Permanent 8,082 449 Floodplain

UT6a1 Per Realignment / Fill Permanent 476 69 Floodplain

UT6e Per Realignment / Fill Permanent 467 55 Floodplain

Wet 01 Buffer PEM Stream Channel Permanent 88 N/A Open Water

Wet 02 PEM Stream Channel Permanent 1207 N/A Open Water

Wet 02 PEM Haul Road Temporary 3301 N/A PEM

Wet 02 PEM Floodplain Grading Temporary 8391 N/A PEM


Wet 02 Buffer PEM Haul Road Temporary 372 N/A PEM

Wet 02 Buffer PEM Floodplain Grading Temporary 11043 N/A PEM




















Wet 08 PEM Haul Road Temporary 12508 N/A PEM





Aquatic Resource Name1

Existing Resource

Class Activity

Impact Duration

Impact Area

(square ft)

Impact Length

(linear ft)

Proposed resource class

post-construction













Total Temporary and Permanent Impacts 186,346 1425

Table 19: Table of Potential Impacts to Existing Resources




LITERATURE CITED

1. Cowardin, L.M, Carter, V., Golet, F.C., and LaRoe, E.T., 1979. Classification of wetlands

and deepwater habitats of the United States. U.S. Fish and Wildlife Service. FWS/OBS-

79/31.

2. Davis, S., R. Starr and C. Eng., 2014. Rapid Stream Restoration Monitoring Protocols. U.S.

Fish and Wildlife Service. Annapolis, MD. CBFO-S14-01

3. DK Books. (Designer). Lake Formation [Web Graphic]. Retrieved from http://www.clipart.dk.co.uk/1107/subject/Geography/Lake_formation

4. Flores, H., D. McMonigle, and K. Underwood, 2011. Regenerative Step Pool Storm

Conveyance (SPSC) Design Guidelines, Revision 4. Department of Public Works, Anne

Arundel County Government, Maryland.

http://www.aacounty.org/DPW/Watershed/SPSCdesignguidelinesJan2012rev4.pdf

5. Harman, W., R. Starr, M. Carter, K. Tweedy, M. Clemmons, K. Suggs, C. Miller. 2011. A

SFPF for Developing Stream Assessments, Restoration Goals, Performance Standards and

Standard Operating Procedures. U.S. Environmental Protection Agency, Office of Wetlands,

Oceans, and Watersheds. Washington, D.C.

6. Harman, W., R. Starr, M. Carter, K. Tweedy, M. Clemmons, K. Suggs, C. Miller. 2012. A

Function-Based Framework for Stream Assessment and Restoration Projects. U.S.

Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds,

Washington, D.C. EPA 843-K-12-006.

7. Hayes, M., 1996. Maryland and the District of Columbia Wetland Resources. National Water

Summary- Wetland Resources. U.S. Geological Survey, Washington, D.C. Water Supply

Paper 2425.

8. Hey, R.D., 2006. Fluvial Geomorphological Methodology for Natural Stable Channel

Design. Journal of American Water Resources Association 42(2):357-374.

9. Kaushal, S., P. Groffman, P. Mayer, E. Striz and A. Gold. 2008. Effects of stream restoration

on denitrification at the riparian-stream interface of an urbanizing watershed of the mid-

Atlantic US. Ecological Applications. 18(3): 789-804

10. Leopold, L.B., M.G. Wolman, J.P. Miller. 1992. Fluvial Processes in Geomorphology. Dover

Publications, Inc. New York.

11. Maryland Department of the Environment, 2006. Prioritizing Sites for Wetland Restoration,

Mitigation, and Preservation in Maryland. Wetlands and Waterways Program, Baltimore,

MD.

12. McCandless, T.L. & R.A. Everett. 2002. Maryland stream survey: Bankfull discharge and

channel characteristics in the Piedmont hydrologic region. U.S. Fish and Wildlife Service,

Annapolis, MD. CBFO-S02-02.

http://www.clipart.dk.co.uk/1107/subject/Geography/Lake_formation




13. McCandless, T. (2003). Maryland stream survey: Bankfull discharge and channel

characteristics in the Coastal Plains hydrologic region. Annapolis, MD: US Fish and

Wildlife Service

14. Mitchell, J.C., A.R. Breisch, and K.A. Buhlmann. 2006. Habitat Management Guidelines for

Amphibians and Reptiles of the Northeastern United States. Partners in Amphibian and

Reptile Conservation, Technical Publication HMG-3, Montgomery, Alabama. 108 pp.

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Service. H.210.NEH.654. http://policy.nrcs.usda.gov/index.aspx

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(WARSSS). Wildland Hydrology Books, Fort Collins, CO. http://www.epa.gov/warsss

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Wildland Hydrology. Pagosa Springs, CO.

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Assessment Methodology. U.S. Fish and Wildlife Service. Annapolis, MD. CBFO-S15-06.

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Process Guidelines. U.S. Fish and Wildlife Service. Annapolis, MD. CBFO-S16-03.

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22. Tweedy, K.L. 2008. A Methodology for Predicting Channel Form in Coastal Plain

Headwater Systems. In Conference Proceedings: Stream Restoration in the Southeast:

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23. U.S. Geological Survey, 2012, The StreamStats program for Maryland, online at

http://water.usgs.gov/osw/streamstats/maryland.html.

24. Williams, D. D., 1996. Environmental Constraints in Temportary Fresh Waters and Their

Consequences for the Insect Fauna. Journal of the North American Benthological Society,

15(4), 635

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Environmental Investments. Army Engineer Inst. For Water Resources, Fort Belvoir, VA.

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http://policy.nrcs.usda.gov/index.aspx

http://www.epa.gov/warsss

http://water.usgs.gov/osw/streamstats/maryland.html


U. S. Fish and Wildlife Service June 2015

Chesapeake Bay Field Office Page | A

APPENDIX A Assessment and Design Review Checklists



Chesapeake Bay Field Office Page | B

APPENDIX B Watershed Assessment



Chesapeake Bay Field Office Page | C

APPENDIX C Level 3 Assessment Representative Reaches Data



Chesapeake Bay Field Office Page | D

APPENDIX D DNR MBSS Biology Report



Chesapeake Bay Field Office Page | E

APPENDIX E Wetland Assessment



Chesapeake Bay Field Office Page | F

APPENDIX F Soil Trench Data



Chesapeake Bay Field Office Page | G

APPENDIX G Project Reach Specific Design Criteria



Chesapeake Bay Field Office Page | H

APPENDIX H Implementation Costs



Chesapeake Bay Field Office Page | I

APPENDIX I Velocity Calculations



Chesapeake Bay Field Office Page | J

APPENDIX J HEC-RAS: Existing and Proposed



Chesapeake Bay Field Office Page | K

APPENDIX K Planting Plan



Chesapeake Bay Field Office Page | L

APPENDIX L Impacts to Existing Resources