NC Wetland Assessment Method A new planning and regulatory tool in North Carolina

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1 NC Wetland Assessment Method A new planning and regulatory tool in North Carolina Presented to Southeast Wetland Work Group August 6,

2 Mountain Bog DuPont State Forest 2

3 NC Wetland Functional Assessment Team (WFAT) Developed by interagency team from 2003 to 2008 Federal agencies US Army Corps of Engineers Dave Lekson and Amanda Jones Environmental Protection Agency Becky Fox Federal Highway Administration Donny Brew US Fish and Wildlife Service Howard Hall State agencies NC Department of Transportation LeiLani Paugh (co-chair) NC Division of Coastal Management Melissa Carle and Steve Sollod NC Division of Water Quality John Dorney (co-chair) NC Ecosystem Enhancement Program Jim Stanfill NC Natural Heritage Program Mike Schafale NC Wildlife Resources Commission David Cox Consultants Ecoscience, Corp. (Sandy Smith, Matt Cusack and Brad Allen) 3

4 Background Presently, DWQ and Corps regulate stream and wetland fill by length and acres, respectively Interest in DENR, DOT and Corps of Engineers administration to regulate based on wetland and stream value (quality) 4

5 Progress to date NC Wetlands Assessment Method (NC WAM) completed Interagency Team met for past six years Developed rapid assessment method Rapid method defined as taking no more than 15 minutes per site after training Beta-tested method with Regional staff and others including consultants Final method done April 2008 Training for RO and Corps staff begun in fall 2008 Six classes held as of mid

6 What is NC WAM? General considerations High, Medium and Low values by separate function and overall Within wetland type Comparisons between wetland type regulatory agency decision Condition compare to reference site Opportunity noted used as appropriate 6

7 Three Main Functions Hydrology Water Quality Habitat 7

8 Hydrology Surface storage and retention Subsurface storage and retention 8

9 Water Storage Floodplain Pool 9

10 Water Quality Particulate change Soluble change Pathogen change Physical change For interstream flat wetlands NC WAM uses Pollution Change instead 10

11 Habitat Physical structure Vegetation composition Landscape patch structure Uniqueness 11

12 Stressors Hydrological modifications Surface discharge into/out of wetland Sub-surface discharge into/out of wetland Habitat/Plant Community alteration Signs of vegetation stress 12

13 Key to Wetland Types Identified and described 16 general wetland types with dichotomous key (see handout) Narrative descriptions with soil, plant species, landscape position, etc. Correlated with Natural Heritage types, NC CREWS (Coastal Management) types HGM types Mitigation types SMG3 13

14 The 16 General Wetland Types Mountain Bogs Salt/Brackish Marsh Estuarine Woody Non-Tidal Freshwater Marsh Tidal Freshwater Marsh Pine Savannas Seeps Bottomland Hardwood Forest Riverine Swamp Forest Headwater Forest Floodplain Pool Pocosin Hardwood Flats Pine Flats Small Basin Wetlands Non-Riverine Swamp Forest 14

15 Non-Tidal Freshwater Marsh Concord,NC 15

16 Riverine Swamp Forest Goose Creek State Park, NC 16

17 Floodplain Pool Deep River near Sanford, NC 17

18 Small Basin Wetland Mecklenburg County 18

19 Hardwood Flat Bonnerton tract, Beaufort County 19

20 Pretty Pond Bay Robeson County 20

21 Overall Evaluation Process One Field Assessment Form (four pages) with all metrics (see example) Form completed in field with some office map work Evaluate with rating calculator (computer program) Boolean logic completed by Team for each wetland type Systematic combination of each subfunction Generates rating of High, Medium or Low for each of up to ten sub-functions, three functions and then one overall rating. 21

22 Boolean Logic process An example Riverine Swamp Forest: Hydrology Surface Storage and Retention Stem Density A B C Scoring Surface Storage and Retention A AA AB AC High B BA BB BC Medium C CA CB CC Low Surface Storage and Retention assessment area condition metric Consider both increase and decrease in hydrology. Compare to reference wetland if applicable (see User Manual). If not applicable, then rate based on evidence of disturbance to hydrology. Refer to the North Carolina Scope and Effect Guide for the zone of influence of ditches in hydric soils. A Surface water storage capacity and duration not altered B Surface water storage capacity or duration altered, but not substantially (typically, not sufficient to change vegetation). C Surface water storage capacity or duration substantially altered (typically, alteration sufficient to result in vegetation change) (examples: diversion, man-made berms, intensive ditching, beaver dams, stream incision) Stem Density assessment area condition metric A Forested or contains dense shrubs B Medium density shrubs, canopy may be present but disturbed C Only herbaceous species or bare ground 22

23 Field testing and calibration Tested on more than 300 sites across state Tested more than one example of each of the 16 wetland types Tested pristine and impacted sites (high and low) Beta testing completed Raleigh with 14 testers Asheville with 18 testers Washington/Wilmington with 26 testers EPA grants underway to calibrate/modify NC WAM as needed in next two years headwater forests and small basin wetlands 23

24 Wetland Tool Box Web-based compilation of known and evaluated wetland sites Site maps Photos Completed forms Use to calibrate and train staff Anyone will be able to submit/post sites When done, available to public maintained by DWQ 24

25 Final phase Draft version of report to joint public notice in February 2007 Final version after public comments April 2008 Replaces DWQ Wetland Rating System Training for agency staff began fall 2008 Four-day classes with ecoregion focus (coastal, piedmont, or mountains) Written manual Field and lecture Written test Schedule for future classes TBD due to budget issues SMG4 25

26 Final phase (cont.) Training for private sector Will be offered by private, non-profit with agency instructors DWQ and Corps do not have enough staff to meet the anticipated need for private sector training Timeline winter 2009 or winter 2010 most likely 26

27 Implementation, or: We ve built a hammer, now what? NC WAM is the tool. Next question, how to use it. Decision by regulatory agencies not Wetland Team. Implementation Team has met five times Corps of Engineers Dave Lekson Environmental Protection Agency Kathy Matthews Division of Water Quality John Dorney Division of Coastal Management Steve Sollod 27

28 Implementation Schedule Final method after public comment April Implementation by Corps, EPA and DWQ after more discussions with EEP and DOT separate public notice and comments in middle of

29 Implementation- Future Uses Will use NC WAM for Avoidance and minimization Mitigation and enhancement based on functional uplift Watershed assessment Wetland monitoring Training 29

30 Mitigation types by NC WAM type Mitigation Type NC WAM Type CAMA coastal/wetland Riverine Riparian Non-riparian, wetter variety Non-riparian, drier variety Salt/Brackish Marsh Riverine swamp forest, non-tidal freshwater marsh, tidal freshwater marsh Bottomland hardwood forest, headwater wetland, floodplain pool, mountain bog Non-riverine swamp forest, seep, small basin wetland, pocosin, estuarine woody Pine flat, pine savannah, hardwood flat 30

31 Avoidance, minimization and mitigation In general, impacts to lower quality wetlands will require less mitigation and be easier to permit. Impacts to higher quality wetlands will require more mitigation and be harder to permit. Essentially, we will replace functions instead of acres for wetlands. Stay tuned for details this year. 31

32 Functional Uplift from Enhancement Current state rules require 1:1 restoration or creation for mitigation to achieve no net loss Possible to use NC WAM to calculate functional uplift from enhancement and count net gain of function towards no net loss Calculate overall wetland function Current condition, versus Enhanced condition Determine acreage increase in function 32

33 Example Meadow Branch site, Robeson County Meadow Branch site along SaddleTree Swamp in Robeson County (southeastern coastal plain) Intact riverine swamp forest and bottomland hardwood forest Saddletree Swamp has been ditched with spoil berm parallel to stream (4 to 6 feet high) Very common situation in NC coastal plain Also old logging road with fill on site 33

34 Mitigation site plan EEP project 34

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36 Example of functional uplift with NC WAM (cont.) State in-lieu fee program (Ecosystem Enhancement Program) plans to remove berm along stream but stream will still be dredged regularly due to upslope flooding concerns Today little mitigation value for site since enhancement does not count toward 1:1 restoration/creation In NC, all mitigation sites deduct one credit from restore/create (no net loss) and one credit from other (could be preservation at 5:1 ratio) 36

37 Proposed method to calculate functional uplift Overall, compare present condition of wetland to future condition after enhancement to calculate functional uplift Use NC WAM to calculate existing condition and to project future condition Overall function High = 3, Medium = 2, and Low = 1 37

38 Proposed method to calculate functional uplift - equation EnhAcres(MitQual post EnhQual pre ) Functional uplift = EnhTypeRatio Equation terms - EnhAcres = Enhancement acreage MitQualpost = Mitigation quality post enhancement MitQualpre = Mitigation quality pre enhancement EnhTypeRatio = Enhancment Type Ratio (equals 2:1) 38

39 Meadow Branch site mitigation calculations Mitigation Location Enhance BLH from Low to Medium Enhance RSF from Low to High Preserve BLH Acres (appx) Functional Uplift Acre-equivelants (appx) Restore BLH remove logging road

40 Overall summary of mitigation credits Meadow Branch site present calculations Present policy acre site 0.82 acres of restoration 26 acres of enhancement 10 acres preservation Since site only has 0.82 acres of restoration, therefore has very little overall mitigation value by itself. 40

41 Overall summary of mitigation credits Meadow Branch site with NC WAM With use of NC WAM 34 acres of enhancement which are equivalent to 12.5 acres of restoration and count toward no net loss calculations 0.82 acres of restoration 10 acres of preservation Therefore, site has acres of restoration equivalent and is a very valuable mitigation site. 41

42 Watershed Assessment Indian-Howard Creek watershed in Lincoln County Study done for NC Ecosystem Enhancement Program Local Watershed Plan Visited sample of all likely wetland sites in watershed Visited and rated 67 sites, 33 were wetlands Average size 1.3 acres 42

43 24% % of Total 62% 14% Overall Rating Overall Rating LOW MEDIUM HIGH Figure 3: Overall NC WAM rating as a percentage of total assessments 43

44 Wetland Enhancement Opportunities Functional uplift using NC WAM Uplift from Low to Medium two sites Uplift from Low to High five sites Uplift from Medium to High one site No change in uplift four sites 44

45 Example site Example site Site 63 Bottomland Hardwood Forest heavily grazed 1.5 acres Current condition Low Enhanced condition High (remove cattle and replant) This functional uplift translates into 1.1 acres of restoration equivalents 45

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47 Wetland monitoring Isolated Wetland study in NC and SC NC Brunswick, Columbus, Robeson and Bladen Counties SC Horry, Marion, Florence, and Dillon Counties Visited 90 randomly chosen sites 47 had isolated wetlands Mostly small basin wetlands with some pocosins Collected data on wetland area, depth, vegetation and soils Conducted NC WAM analyses (and others) Intensive monitoring work continuing over next two years 47

48 Horry County Near Grand Strand Wastewater 48

49 NC WAM results for 47 isolated wetland sites Hydrology Water Quality Habitat Overall Function High 77% 43% 49% 53% Medium 18% 45% 19% 36% Low 5% 13% 32% 11% 49

50 Questions? 50

51 More information NC WAM documents available at Mitigation Framework on Corps website at 51