Classifying wetlands and assessing their functions: Using the NC Wetlands Assessment Method (NCWAM) to analyze wetland mitigation sites in the coastal

Classifying wetlands Classifying wetlands and assessing their and assessing their

functions:functions: Using the NC Wetlands Assessment Method Using the NC Wetlands Assessment Method

(NCWAM) to analyze wetland mitigation sites in (NCWAM) to analyze wetland mitigation sites in the coastal plain region.the coastal plain region.

Emily R. BurtonEnvironmental Studies Graduate StudentUniversity of North Carolina, Wilmington

May 5, 2008

North CarolinaNorth Carolina

Wetland Assessment Method

Geography of NC Coastal PlainGeography of NC Coastal Plain

Inner and outer coastal plain Inner and outer coastal plain

ecoregions ecoregions

Broad interstream divides Broad interstream divides

Gentle-sloping plains Gentle-sloping plains

Mineral-based, poorly drained Mineral-based, poorly drained

soilssoils

Cape Fear, White Oak, Neuse, Cape Fear, White Oak, Neuse,

Roanoke, Tar-Pamlico, and Roanoke, Tar-Pamlico, and

Chowan River Basins Chowan River Basins

Aerial Image of North CarolinaAerial Image of North Carolina

Land Use and Wetland LossLand Use and Wetland Loss

Once contained approximately 95% of the Once contained approximately 95% of the state’s 6 million acres of wetlands state’s 6 million acres of wetlands

About 51% of the original wetlands in About 51% of the original wetlands in North Carolina had been lost or altered in North Carolina had been lost or altered in some waysome way

Between 1950 – 1980, approx. 42.2% of Between 1950 – 1980, approx. 42.2% of this loss was caused by agricultural this loss was caused by agricultural activities activities

Converting Wetlands to AgricultureConverting Wetlands to Agriculture Removal of all vegetation and debrisRemoval of all vegetation and debris

Cutting drainage ditches 24-48” deepCutting drainage ditches 24-48” deep

Creating field crownsCreating field crowns

Prior Converted (PC) CroplandPrior Converted (PC) Cropland

Compaction of soils creates a plow-panCompaction of soils creates a plow-pan

NRCS declared PC as those lands that converted NRCS declared PC as those lands that converted wetlands prior to December 23, 1985:wetlands prior to December 23, 1985:

1. Do not flood more than 14 days during 1. Do not flood more than 14 days during the the growing seasongrowing season

2. Agricultural commodity 2. Agricultural commodity

3. Not since been abandoned 3. Not since been abandoned

Definition of WetlandsDefinition of Wetlands USACE 1987 Wetland Delineation Manual USACE 1987 Wetland Delineation Manual

3 Parameters:3 Parameters:

1. Hydrology – presence of water within the 1. Hydrology – presence of water within the upper 12 in. for at least 5% of the growing seasonupper 12 in. for at least 5% of the growing season

2. Hydrophytic vegetation – > 50% wetland 2. Hydrophytic vegetation – > 50% wetland species.species.

3. Hydric Soils – formed under wet conditions 3. Hydric Soils – formed under wet conditions long enough to develop anaerobic conditions in long enough to develop anaerobic conditions in upper 12 in. upper 12 in.

Wetlands and their ImportanceWetlands and their Importance

Swamps, marshes, bogs, pine flats, and Swamps, marshes, bogs, pine flats, and floodplains floodplains

Water quality improvement, flood storage, Water quality improvement, flood storage, groundwater recharge, shoreline erosion groundwater recharge, shoreline erosion protection protection

Provide habitat for fish and wildlifeProvide habitat for fish and wildlife

Opportunities for recreation and aesthetic Opportunities for recreation and aesthetic appreciation appreciation

Regulatory ProtectionsRegulatory Protections

Clean Water Act, 1972Clean Water Act, 1972

Army Corps of EngineersArmy Corps of Engineers

Section 404(b)(1) Guidelines: Section 404(b)(1) Guidelines:

1. Avoid filling wetland resources1. Avoid filling wetland resources

2. Minimize adverse impacts2. Minimize adverse impacts

3. Provide compensatory mitigation3. Provide compensatory mitigation

No Net Loss of WetlandsNo Net Loss of Wetlands 1989, President George Bush Sr. 1989, President George Bush Sr.

Reduce the amount of wetlands impacted Reduce the amount of wetlands impacted

Restore and create new wetlands Restore and create new wetlands

Three ways to provide mitigation through the Three ways to provide mitigation through the regulatory process: regulatory process:

1. Mitigation Banking1. Mitigation Banking2. In-Lieu Fee Process2. In-Lieu Fee Process3. Permittee Process (on-site restoration, 3. Permittee Process (on-site restoration,

enhancement, and/or creation) enhancement, and/or creation)

Mitigation BankingMitigation Banking Early 1990s market-Early 1990s market-

based instrument based instrument

Sponsor creates a “bank” Sponsor creates a “bank” of restored, enhanced, andof restored, enhanced, and/or /or created wetlandscreated wetlands

Made credits available to developers to “buy” Made credits available to developers to “buy”

Provides compensatory mitigation Provides compensatory mitigation in advancein advance of of authorized impactsauthorized impacts

Mitigation Banking (cont.)Mitigation Banking (cont.)

Sponsor submits a prospectus to the Corps and Sponsor submits a prospectus to the Corps and Inter-agency Review TeamInter-agency Review Team

Detailed plan of the bank site and success criteriaDetailed plan of the bank site and success criteria

Mitigation Banking Instrument (MBI) provides the Mitigation Banking Instrument (MBI) provides the legal frameworklegal framework

Sponsor becomes responsible for providing Sponsor becomes responsible for providing mitigation for Corps permits and the long-term mitigation for Corps permits and the long-term management and ecological success of the site. management and ecological success of the site.

North Carolina Department of North Carolina Department of TransportationTransportation

1990 ambitious road-1990 ambitious road-building initiativebuilding initiative

NCDOT responsible for NCDOT responsible for

compensating for an compensating for an increasing amount of increasing amount of wetland losses wetland losses

Increased project delaysIncreased project delays

Wetland mitigation needed to expand and become Wetland mitigation needed to expand and become more pro-active more pro-active

In-Lieu Fee ProcessIn-Lieu Fee Process 1997 North Carolina Wetlands Restoration Program 1997 North Carolina Wetlands Restoration Program

(WRP)(WRP)

Allows permittee to provide funds to Allows permittee to provide funds to an in-lieu-fee sponsor (WRP Fund)an in-lieu-fee sponsor (WRP Fund)

First method of developing a per-acre cost of wetland First method of developing a per-acre cost of wetland restorationrestoration

Mitigating within the same river basin as impactsMitigating within the same river basin as impacts

Reporting and documenting of statewide wetland Reporting and documenting of statewide wetland acreage losses and gains acreage losses and gains

NC Ecosystem Enhancement Program NC Ecosystem Enhancement Program (EEP)(EEP)

2003 MOA between the Corps, 2003 MOA between the Corps, DOT, and DENRDOT, and DENR

More consistent and streamlined approach to More consistent and streamlined approach to mitigationmitigation

Implementation of large-scale watershed-based Implementation of large-scale watershed-based restoration efforts restoration efforts

2004 accepted the transfer and responsibility of 2004 accepted the transfer and responsibility of all of NCDOT’s off-site mitigation projects.all of NCDOT’s off-site mitigation projects.

Wetland Functional AssessmentWetland Functional Assessment Evaluating and tracking wetland Evaluating and tracking wetland

functionfunction

Quantified based on acreage, numbers Quantified based on acreage, numbers

of planted trees survived, and hydrolo-of planted trees survived, and hydrolo-

gical datagical data

Quality measured by the regulator’s best professional Quality measured by the regulator’s best professional judgment (BPJ) judgment (BPJ)

A new method of assessing wetland function was needed A new method of assessing wetland function was needed to make better and more defensible permit decisions to make better and more defensible permit decisions

North Carolina Wetland Assessment North Carolina Wetland Assessment Method (NCWAM)Method (NCWAM)

A team of experts gathered in 2003 to A team of experts gathered in 2003 to analyze approx 40 different existing analyze approx 40 different existing methodologiesmethodologies

NCWAM Draft Manual was released in NCWAM Draft Manual was released in December of 2007December of 2007

Provides an accurate, consistent, rapid, Provides an accurate, consistent, rapid,

observational, and scientifically-based field observational, and scientifically-based field methodmethod

Dichotomous Key to General North Dichotomous Key to General North

Carolina Wetland TypesCarolina Wetland Types

16 general wetland types in NC16 general wetland types in NC

Account for impacts by wetland type Account for impacts by wetland type

Account for the inherent differences in Account for the inherent differences in

function for each wetland typefunction for each wetland type

Bottomland Hardwood ForestBottomland Hardwood Forest

Riverine Swamp ForestRiverine Swamp Forest

Non-Tidal Freshwater Marsh

NCWAM Field FormNCWAM Field Form

Level of function of wetlands based on ratings of Level of function of wetlands based on ratings of indicators of function rather than their actual indicators of function rather than their actual measurements measurements

Evaluation of 22 metrics using observation, Evaluation of 22 metrics using observation, measurement, and BPJmeasurement, and BPJ

NC WAM rating calculatorNC WAM rating calculator converts data into converts data into “High”, “Medium”, or “Low” functional ratings“High”, “Medium”, or “Low” functional ratings

Wetland FunctionsWetland Functions

11 Sub-functions11 Sub-functions

3 Main functions:3 Main functions:

– HydrologyHydrology

– Water QualityWater Quality

– HabitatHabitat

““HighHigh””, , ““MediumMedium”” and and ““LowLow”” ratings ratings –– by separate by separate function and overallfunction and overall

HydrologyHydrology

Surface storage and retentionSurface storage and retention

Subsurface storage Subsurface storage

and retentionand retention

Water QualityWater Quality

Particulate changeParticulate change

Soluble changeSoluble change

Pathogen changePathogen change

Physical changePhysical change

Pollution Change (combination of the first three)Pollution Change (combination of the first three)

HabitatHabitat

Physical structurePhysical structure

Vegetation compositionVegetation composition

Landscape patch structureLandscape patch structure

Habitat UniquenessHabitat Uniqueness

Site Selection for NC WAM Site Selection for NC WAM EvaluationEvaluation

12 mitigation sites selected based on:12 mitigation sites selected based on:

1. Geographical area – Inner and 1. Geographical area – Inner and Outer Outer Coastal PlainCoastal Plain

2. Age of site development – 1993 – 2. Age of site development – 1993 – 2003; “Closed out”2003; “Closed out”

3. Prior land use – PC cropland3. Prior land use – PC cropland

PC RestorationPC Restoration

The most “bang for your buck”The most “bang for your buck” Historically supported hydric soils Historically supported hydric soils

Encompass larger areasEncompass larger areas Minimal restoration design work and costMinimal restoration design work and cost Restored PC croplands = 2,176 acres Restored PC croplands = 2,176 acres

Site RestorationSite Restoration

Drainage ditches plugged and/or filled Drainage ditches plugged and/or filled

Discing, deep ripping, surface scarificationDiscing, deep ripping, surface scarification

Deep RippingDeep Ripping

Help increase permeability rates, surface Help increase permeability rates, surface roughness, hydrological retention, and improve roughness, hydrological retention, and improve vegetation restoration effortsvegetation restoration efforts

Vegetation PlantingVegetation Planting

Within one year of site constructionWithin one year of site construction

Wetland species selected Wetland species selected

according to wetland typeaccording to wetland type

Determined by a reference areaDetermined by a reference area

Saplings planted in rowsSaplings planted in rows

Site MonitoringSite Monitoring

Installation of ground water monitoring gaugesInstallation of ground water monitoring gauges

Vegetation remediation in first 1-2 yearsVegetation remediation in first 1-2 years

Hydrology and vegetation success monitored for Hydrology and vegetation success monitored for 4 – 6 years4 – 6 years

Annual reports submitted to the CorpsAnnual reports submitted to the Corps

MethodologyMethodology

Site restoration plans and monitoring reports Site restoration plans and monitoring reports from NCDOT, the Corps, and EEP from NCDOT, the Corps, and EEP

8 NCDOT-owned, 4 privately 8 NCDOT-owned, 4 privately

owned mitigation banksowned mitigation banks

ArcView/ArcMap GIS mappingArcView/ArcMap GIS mapping

Tools for the FieldTools for the Field

NCWAM forms and Draft ManualNCWAM forms and Draft Manual Soil augerSoil auger Hand-held Global Position System (GPS)Hand-held Global Position System (GPS) Digital cameraDigital camera Pocket rodPocket rod Soil surveysSoil surveys Munsell Soil Color ChartsMunsell Soil Color Charts Compass Compass

Identifying Assessment AreasIdentifying Assessment Areas

Maps showing where hydrology had been Maps showing where hydrology had been restored and wetland vegetation plantedrestored and wetland vegetation planted

Walked and observed for changesWalked and observed for changes

Identified a favorable, homogenous Identified a favorable, homogenous representation of a particular wetland typerepresentation of a particular wetland type

Keyed out using the Dichotomous KeyKeyed out using the Dichotomous Key

Site EvaluationSite Evaluation

Completed NCWAM Form for Completed NCWAM Form for the Assessment Areathe Assessment Area

Digital Photo DocumentationDigital Photo Documentation

GPS recording of Lat/Long GPS recording of Lat/Long coordinatescoordinates

2-5 community types per site2-5 community types per site 37 evaluations total37 evaluations total

NCWAM ResultsNCWAM Results 8/16 NC wetland community types represented8/16 NC wetland community types represented::

11 Hardwood flats 11 Hardwood flats

9 Non-riverine swamp forests 9 Non-riverine swamp forests

6 Riverine swamp forests 6 Riverine swamp forests

4 Bottomland hardwood forests 4 Bottomland hardwood forests

4 Pine flats 4 Pine flats

1 Pine savanna 1 Pine savanna

1 Floodplain pool1 Floodplain pool

1 Non-tidal freshwater marsh 1 Non-tidal freshwater marsh

Table 1: Functional Results of Wetland Mitigation Sites

Function Functional Rating

Low Medium High

Hydrology -- Condition 11% 13.5% 75.5%

Water Quality -- Condition 13.5% 19% 67.5%

Water Quality -- Opportun 11% 16% 73%

Habitat -- Condition 56.5% 30% 13.5%

Overall Rating 16% 19% 65%

Table 2: Results of Wetland Functions for Individual Assessment SitesTable 2: Results of Wetland Functions for Individual Assessment Sites Site Name/Assessment

Area (AA)Wetland Community

TypeHydrolCond.

Water Qual

Cond.

HabitatCond.

Overall

1. Scuppernong River

AA 1 Non-Riverine Swamp Forest

High High Medium High

AA 2 Hardwood Flat Medium High High High

2. Bull Farms

AA 1 Floodplain Pool High High High High

AA 2 Bottomland Hardwood Forest

High Low Low Low

AA 3 Riverine Swamp Forest Medium Low Low Low


High Medium Low Medium

AA 5 Riverine Swamp Forest High High Low High

3. Mildred Woods

AA 1 Pine Flat High High Medium High

AA 2 Hardwood Flat Medium High Low Medium


High High Low High


High High Low High

Table 2: Results of Wetland Functions for Individual Assessment SitesTable 2: Results of Wetland Functions for Individual Assessment Sites

Site Name/Assessment Area (AA)

Wetland Community Type

HydrologyCond.

Water Qual

HabitatCond.

Overall

4. Dismal Swamp

AA 1 Riverine Swamp Forest High High High High





5. Hidden Lake

AA 1 (Woodward Tract) Hardwood Flat High High Low High

AA 2 (Morris Tract) Hardwood Flat High High Low High

6. Gurley Tract

AA 1 Hardwood Flat High High Medium High

AA 2 Bottomland hardwood Forest


7. Barra Farms (P-I)

AA 1 Hardwood Flat High Medium Medium Medium



AA 3 Pine Flat Medium Medium Medium Medium

AA 4 Hardwood Flat High High Low High




HydrologyCond.

Water Qual

Cond.

HabitatCond.

Overall

8. Long Swamp

AA 1 Hardwood Flat High High Medium High



9. Haws Run

AA 1 Riverine S. Forest (created)

Low Medium Low Low

AA 2 Riverine Swamp Forest High High Low High


AA 4 Pine Savanna High High Low High

10. Dowd Dairy




High High Low High





HydrologyCond.

Water Qual

Cond.

HabitatCond.

Overall

11. ABC Site


Low Low Low Low

AA 2 Hardwood Flat Low Low Low Low

12. Bear Creek Mill Branch Site

AA 1 Riverine Swamp Forest Low Low Low Low

AA 2 Non-Tidal Fresh Water Marsh

High High High High

ResultsResults

4 out of 12 mitigation sites rated 4 out of 12 mitigation sites rated ““HighHigh”” overall for all assessment areas evaluated: overall for all assessment areas evaluated:

Scuppernong River CorridorScuppernong River Corridor

Dismal SwampDismal Swamp

Hidden LakeHidden Lake

Gurley Tract Gurley Tract

One rated One rated ““LowLow”” overall: overall:

ABCABC

Results (cont.)Results (cont.)

3 other sites had 3 other sites had ““LowLow”” overall ratings overall ratings

Alterations due to beaver Alterations due to beaver

activityactivity

Lack of wetland functions due to presence of Lack of wetland functions due to presence of stream channelization, man-made berms, or soil stream channelization, man-made berms, or soil compactioncompaction

Negative effects on all three wetland functionsNegative effects on all three wetland functions

DiscussionDiscussion

Identifying the type of wetland Identifying the type of wetland community presentcommunity present

Different than what was originally Different than what was originally planned planned

Post-restoration events substantially altered site Post-restoration events substantially altered site conditions conditions

For purposes of consistency For purposes of consistency site identified as it site identified as it appeared appeared

ConclusionsConclusions

NC WAM has the ability to determine wetland NC WAM has the ability to determine wetland functionality accuratelyfunctionality accurately

Hydrology “High” (75.5%) – first function to be Hydrology “High” (75.5%) – first function to be replaced after a site is constructedreplaced after a site is constructed

Water Quality “High” (67%) – relative to Water Quality “High” (67%) – relative to

inundation duration, vegetation structure, and inundation duration, vegetation structure, and opportunity (surrounding land use)opportunity (surrounding land use)

Habitat “Low” (56.5%) – can take decades to Habitat “Low” (56.5%) – can take decades to hundreds of years to re-establish hundreds of years to re-establish

Lack of OpportunityLack of Opportunity

Nearby stormwater directed away from the Nearby stormwater directed away from the wetland via ditches or storm drainswetland via ditches or storm drains

Stream channelization Stream channelization

minimizes opportunity minimizes opportunity

for over-for over- bank floodingbank flooding

Restoration MethodsRestoration Methods Standard method of restoring PC croplands works Standard method of restoring PC croplands works

best for hydrology and water quality functionsbest for hydrology and water quality functions

Recommend introducing coarse woody debris to Recommend introducing coarse woody debris to improve habitat functionalityimprove habitat functionality

““Less is better” Less is better” (eg. ABC Site)(eg. ABC Site)

Creation is not preferred Creation is not preferred (eg. Haws Runs Site) (eg. Haws Runs Site)

NC WAM: A Validation for SuccessNC WAM: A Validation for Success

Performance measures prior to NCWAM based on Performance measures prior to NCWAM based on minimum standard: minimum standard:

1. Hydrology present at least 12.5% of GS 1. Hydrology present at least 12.5% of GS 2. Coverage of hydrophytic vegetation at 2. Coverage of hydrophytic vegetation at

least 260 stems/acreleast 260 stems/acre

NCWAM examines a range of wetland functions NCWAM examines a range of wetland functions covering a number of observable characteristics covering a number of observable characteristics

Valuable and accurate tool for evaluating success Valuable and accurate tool for evaluating success of mitigated wetlandsof mitigated wetlands

Tracking Function of Mitigation SitesTracking Function of Mitigation Sites

Enhancement areas – evaluate before and after Enhancement areas – evaluate before and after improvements to track functional uplift improvements to track functional uplift

Restoration areas – evaluate before restoration Restoration areas – evaluate before restoration plan approval to determine goals; require as part plan approval to determine goals; require as part of the mitigation monitoring requirementof the mitigation monitoring requirement

““High” ratings required for true High” ratings required for true

functional replacementfunctional replacement

Final WordFinal Word

Mitigation sites are constantly subject to Mitigation sites are constantly subject to changechange

Recommend further evaluation of mitigation Recommend further evaluation of mitigation sites using NCWAMsites using NCWAM

Future study for Regulatory Co-op??Future study for Regulatory Co-op??

Thanks for the good times!!Thanks for the good times!!

Documents

Classifying wetlands and assessing their functions: Using the NC Wetlands Assessment Method (NCWAM) to analyze wetland mitigation sites in the coastal