Floodplain Management and Restoration in Charlotte-Mecklenburg Dave Canaan Director – Water & Land Resources

Floodplain ManagementFloodplain Management and Restoration in and Restoration in Charlotte-MecklenburgCharlotte-Mecklenburg

Dave CanaanDirector – Water & Land Resources

Storm Water ManagementStorm Water Management

CHARLOTTE-MECKLENBURGSTORM WATER SERVICES

Mecklenburg County SWS FEMA streams (> 1 sq. mi. watershed) County areas (pipes, swales, ditches) 5 of 6 towns (pipes, swales, ditches)

City of Charlotte SWS Open systems (creeks & swales) Closed systems (culverts & pipes)

BackgroundBackground

County Storm Water Major Streams

– FEMA or mapped streams/river– Greater than 1 square mile

drainage area– County wide

Minor System – Less than 1 square mile

drainage area


County Storm Water Partnerships ($1.8M)

– City– NPDES Permit– BMP projects

– Towns– NPDES Permit– Investigations, design and

construction


Municipalities ($35M+/-) Minor System

– Less than 1 square mile drainage area

– Programs vary greatly Water Quality per CWA

County VisionCounty Vision

A safe community A healthy community A livable community A prosperous community A well-governed community

Priorities in Mecklenburg County:

Commitment at the TopCommitment at the Top

““The Little Sugar Creek watershed is The Little Sugar Creek watershed is one of the most severely polluted one of the most severely polluted watersheds in North Carolina (NCDWQ watersheds in North Carolina (NCDWQ Catawba River Basinwide Water Quality Catawba River Basinwide Water Quality Plan pp. 4-24 to 4-27).”Plan pp. 4-24 to 4-27).”

"The County Commission herein finds that the "The County Commission herein finds that the public policy of Mecklenburg County is that our public policy of Mecklenburg County is that our surface waters --- creeks, tributaries, ponds and surface waters --- creeks, tributaries, ponds and lakes --- are lakes --- are a natural resource to be protecteda natural resource to be protected as a as a source of natural beauty and recreation.source of natural beauty and recreation.

Further, that the use of our creeks, tributaries, Further, that the use of our creeks, tributaries, ponds and lakes as a ponds and lakes as a stormwater disposal method stormwater disposal method shall be secondaryshall be secondary to the preservation of creeks, to the preservation of creeks, tributaries, ponds and lakes.”tributaries, ponds and lakes.”

Multi-objective Floodplain Multi-objective Floodplain PlanningPlanning

BOCC Adopted Initiatives; Floodplain Management Guidance Doc. (Dec 97) SWIM Initiative (Dec 99) Greenway Master Plan (1999) Flood Mitigation Plans (2003) All Hazards Plan (2005)

Charlotte-MecklenburgCharlotte-Mecklenburg

Sugar CreekSugar Creek

Little Sugar CreekLittle Sugar Creek

HiddenHiddenValleyValley

Watersheds / BasinsWatersheds / Basins

330± miles of FEMA streams

32 watersheds

All water in Mecklenburg County (except Catawba River) originates in Mecklenburg County

MissionMission

Reducing the potential for the loss of life and property due to flooding.

Enhancing the natural and beneficial functions of the floodplain.

Floodplain Management strives to build a Floodplain Management strives to build a Livable Community byLivable Community by::

Floodplain Management Floodplain Management Goals & ObjectivesGoals & Objectives

Mitigation/RestorationMitigation/Restoration(Correction)(Correction)

PRESERVATION (Protection)

PASTPASTFUTUREFUTURE

PROJECTSPROJECTS

ORDINANCESORDINANCES

County Storm Water ServicesCounty Storm Water ServicesCapital ProgramCapital Program

Three Components: Flood Mitigation Program Water Quality Program Engineering Program

(Stream Restoration/Repairs)

PARTNERSHIPS

Floodplain Management Floodplain Management PartnersPartners

Floodplain Management Floodplain Management ElementsElements

Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification

System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program

MaintenanceMaintenance

Storm Water Operations Division Blockage Removal Encroachments / Notices of Violation Vegetation Management Acquired parcel maintenance




Rainfall / Stream GaugesRainfall / Stream Gauges

PARTNERPARTNER

United States United States Geologic Geologic SurveySurvey

(USGS)(USGS)




Early Warning SystemEarly Warning System

Warning dissem ination

subsystem

Data collection & transm ission

subsystem

Data filing, displaying, & dissem inating

subsystem

Forecasting subsystem

Threat- recognition subsystem

Flood response plan

Response and recovery

( c) 1999, Dav id F o rd C onsu lting Engineers

W arning

Early Warning SystemEarly Warning System




Re-Mapping - 1999Re-Mapping - 1999

1975: Flood Insurance Rate 1975: Flood Insurance Rate Maps (FIRM)Maps (FIRM)

Community Rating System Community Rating System (insurance discounts)(insurance discounts)

1999-2001:1999-2001:

Re-Mapping - 1999Re-Mapping - 1999

Re-MappingRe-Mapping

STUDY STUDY RESULTSRESULTS

Existing Existing ConditionsConditions

+2.0 feet +2.0 feet

Future Future ConditionsConditions

+4.6 feet+4.6 feet

3,000 - 4,000

3,000 - 4,000

structures in

structures in

the floodplain

the floodplain




Service RequestsService Requests

Irwin Creek at I-77

FloodingFlooding

ErosionErosion

BlockagesBlockages

Property DamageProperty Damage




History OverviewHistory Overview

1890’s - 1920’s: Catawba River dams Duke Energy

1910’s - 1930’s: creek dredging, widening drainage, irrigation, agricultural districts

1950’s: chemical deodorizers Meck County Dept. of Environmental Protection

1960’s - 1995: riprap engineering department

1995 - present: soil bioengineering Storm Water Services

1890’s - 1920’s1890’s - 1920’s

Catawba River dams - Duke Energy Series of 11 dams/reservoirs drinking water, hydro power, flood control, navigation created setbacks & buffers from water bodies swimming, fishing & recreation

1910’s - 1930’s1910’s - 1930’s

US Army Corps of Engineers Creating navigable waters of the state & U.S.

“Dredge on Briar Creek”

Dredge, Widen, StraightenDredge, Widen, Straighten

Agricultural Districts better field drainage eliminated “swamps” &

“marshes” no more groundwater recharge

“Drainage Work in Mecklenburg

County”

circa 1911


Old creek alignment for Little Sugar Creek

New & “improved” alignment for Little Sugar Creek

Sewer Department centralized collection & treatment, first WWTP, 1923


Federal Funding North Carolina Emergency

Relief Administration, 1936

“Clearing Little Sugar Creek & tributaries”

“Cleaning out Long Creek”“Clear & ditch Toby

Creek”“Briar Creek drainage”

“Drainage of McDowell Creek”

$16,076.70

$3,877.30$95,406.47

$2,627.70

$3,447.10

1950’s1950’s

“Chemical deodorizers should take of it!” Meck County Dept. of

Environmental Protection

County streams had little aquatic life, minimal vegetative cover and strong odors.

1960’s - 19951960’s - 1995

Riprap - King of the Queen City! Worked for just about any engineering “solution” Fixes the stream horizontally Environmental consequences of “flush & gush” weren’t

understood Environmental movement was in its infancy 1972 - Clean Water Act

Bio EngineeringBio EngineeringIrwin Creek (1998)

Natural Channel DesignNatural Channel Design

Hydraulic response ….. altered dimension

A narrower thalweg forms in Briar Creek TWO months after placing SIX alternating rock vanes (2000).Briar Creek, August 12,

2000




Flood Mitigation PurposeFlood Mitigation Purpose

Community Health and Safety Focus Area

Reduce Injury

Flood Mitigation Flood Mitigation Planning HistoryPlanning History

1997 Floodplain Management Guidance Document

1999 Adopted original Watershed Plans

2000 Initiate Mitigation (Buyout) Program

2004 Adopted updated Watershed Plans

2004 Expanded Flood Mitigation Capital Program




Problem DefinitionProblem Definition

Doral ApartmentsBriar Creek July 22-24, 1997

3,000 - 4,000

3,000 - 4,000

structures in

structures in

the floodplain

the floodplain

Problem DefinitionProblem Definition

Myers Park ManorBriar Creek July 22-24, 1997

Flood MitigationFlood MitigationAccomplishmentsAccomplishments

Years 2000 - 2005 135 buildings removed from the

floodplain (90% participate) 80 acres of deeded public open

space Buyout Funding (Awarded)

$14.1M - Federal Funds $1.7M - State Funds $8.9M - Local Storm Water Funds

35 additional buildings & 40 acres of open space within the floodplain through efforts with Real Estate Services

Buyout ProgramBuyout Program

Issues Voluntary = No Condemnation Fair Market Value Prioritizing thru Mitigation Plans Demolition vs. Relocation Owners vs. Renters Hazardous Materials Vacant Land & What to Do With It

Buyout AreaBuyout Area

Wes

tfie

ld R

oad

Wes

tfie

ld R

oad

Brandywine RoadBrandywine Road

Future ParkFuture ParkRoad ShoppingRoad ShoppingCenter (1956)Center (1956)

Future MyersFuture MyersPark ManorPark Manor

(1951)(1951)

Lit

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ug

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Cre

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19381938

19511951

19561956Lit

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ar

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Lit

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Future Woodlawn Road

Future Woodlawn Road

MyersMyersParkPark

ManorManorFuture ParkFuture Park

Road ShoppingRoad ShoppingCenter (1956)Center (1956)

MyersMyersParkPark

ManorManor

Lit

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Cre

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Lit

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ParkParkRoadRoad

ShoppingShoppingCenterCenter


19971997

19951995

20032003

BEFORE


AFTER

High WaterBEFORE - July 97

AFTER


Hidden Valley - Step 1Property Acquisition

(1) Fee Title

(2) Deed Restriction

(3) Voluntary

(4) No Condemnation


Hidden Valley - Step 2Structure Demolition

(1) Relocation

(2) Habitat for Humanity

(3) Fire Dept. Training

(4) SWAT Police Training


Hidden Valley - Step 3Environmental Restoration

(1) Environmental

(2) Water-Oriented

(3) Open Space / Re-Forested

(4) Greenway / Recreational


Hidden Valley Eco-Restoration Wetland $1± million acquisition cost $1.2± million construction cost $940,000 CWMTF grant 1½ sq. mile watershed 17 homes purchased & razed greenway planned additional vacant land purchases additional funds from Wetlands Restoration Program

THANK YOU

Documents

Floodplain Management and Restoration in Charlotte-Mecklenburg Dave Canaan Director – Water & Land Resources