NC Wetland Assessment Method A new world for wetland permitting and mitigation

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NC Wetland Assessment Method A new world for
wetland permitting and mitigation

• Presented to
• Watershed Assessment Forum
• June 9, 2009

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Mountain BogDuPont State Forest
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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)

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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)

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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

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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

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Three Main Functions

• Hydrology
• Water Quality
• Habitat

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Hydrology

• Surface storage and retention
• Subsurface storage and retention

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Water Quality

• Particulate change
• Soluble change
• Pathogen change
• Physical change
• For interstream flat wetlands NC WAM uses
  Pollution Change instead

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Habitat

• Physical structure
• Vegetation composition
• Landscape patch structure
• Uniqueness

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Stressors

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

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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

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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

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Non-TidalFreshwater MarshConcord,NC
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Riverine Swamp ForestGoose Creek State Park, NC
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Floodplain PoolDeep River near Sanford, NC
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Small Basin Wetland MecklenburgCounty
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Hardwood FlatBonnerton tract, Beaufort County
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Pretty Pond BayRobeson County
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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.

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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

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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

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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

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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

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Implementation, or Weve 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

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Implementation Schedule

• Final method after public comment April 2008.
• Implementation by Corps, EPA and DWQ after more
  discussions with EEP and DOT separate public
  notice and comments in middle of 2009.

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Implementation- Future Uses

• Will use NC WAM for
• Avoidance and minimization
• Mitigation and enhancement based on functional
  uplift
• Watershed assessment
• Wetland monitoring
• Training

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Mitigation types by NC WAM type
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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.

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Functional Uplift from Enhancement

• Current state rules require 11 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

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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

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Mitigation site plan EEP project
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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 11
  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 51 ratio)

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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

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Proposed method to calculate functional uplift -
equation
EnhAcres(MitQualpost EnhQualpre) Functional
uplift EnhTypeRatio Equation terms -
EnhAcres Enhancement acreage MitQualpost
Mitigation quality post enhancement MitQualpre
Mitigation quality pre enhancement EnhTypeRatio
Enhancment Type Ratio (equals 21)
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Meadow Branch site mitigation calculations
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Overall summary of mitigation credits Meadow
Branch site present calculations

• Present policy 44.82 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.

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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 13.32 acres of restoration
  equivalent and is a very valuable mitigation
  site.

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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

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Figure 3 Overall NC WAM rating as a percentage
of total assessments
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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

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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

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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

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Horry CountyNear Grand Strand Wastewater
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NC WAM results for 47 isolated wetland sites
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Questions?
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More information

• NC WAM documents available at
• http//h2o.enr.state.nc.us/ncwetlands/pdu.htm

Mitigation Framework on Corps website at
http//www.saw.usace.army.mil/WETLANDS/notices/20
08/PNforMitigationChanges6-3-2008.pdf