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Rapid Assessment Method

Rapid Assessment Method. Brian Smith Water Quality/Biology Environmental Specialist brian.smith @fhwa.dot.gov. National Wetland Mitigation Banking Study Technical and Procedural Support to Mitigation Banking Guidance (Dec 1995). Rapid Assessment Method. Examples

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Rapid Assessment Method

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  1. Rapid Assessment Method Brian Smith Water Quality/Biology Environmental Specialist brian.smith @fhwa.dot.gov

  2. National Wetland Mitigation Banking Study Technical and Procedural Support to Mitigation Banking Guidance (Dec 1995)

  3. Rapid Assessment Method Examples Minnesota Routine Assessment Method Montana Department of Transportation Rouge River Project (MI) Wetland Rapid Assessment Procedure (FL) McHenry County, Illinois Advanced Identification (ADID) Study Evaluation Methodology

  4. Geomorphic setting Hydrology is a key factor Assigns wetlands to HGM subclass Reference and reference standard wetlands used Models based on data from reference wetlands This Procedure is not HGM but…

  5. Lacks landscape focus Costly to implement Guidebook testing Inconsistent Uncoordinated Depends on funding Variables based on indicators not processes Diagnostic not prescriptive Does not contribute to mitigation design No guarantees for success Hydrology, WL, native vegetation No structure for inserting success factors HGM APPROACH

  6. Rapid Assessment • Incorporates many HGM concepts • Follows qualitative, rule-based modeling • Rules replace equations or quantitative data • Draws on and synthesizes what is known without introducing unknown parameters • Expedient, less costly, less time consuming

  7. Rapid Assessment • Functional indicators of each function • Functional indicators = site variables • Range of conditions = variable conditions • An index (functional index) generated for each function • Indicates functional capacity • Only compared within same HGM class and region

  8. Wetlands

  9. Travel Patterns Overlaid With Sewered Areas

  10. Listed Species Habitat, Sewered Areas and Travel Patterns

  11. “The proximity of development may alter wetland functions and values. …evaluation of the resource must consider… adjacent land use and associated interrelationships”. National Academy of Science (NAS) regarding wetland loss and compensation: Reduce Subjectivity Consider Proximity of Development Consider adjacent land use and associated interrelationships

  12. Rapid Assessment Objectives • Wetland evaluation method • Rapid • Economical • Repeatable

  13. Rapid Assessment Objectives • Meets needs of local regulatory agencies • Identifies functions and values • Incorporates some principles of HGM • Considers spatial arrangements and scale • Identifies human activities as part of the environment • Enhance databases

  14. Stay away from: • Using too many attributes and indicators • Having too many categories • Subjectivity • Frivolous weighting schemes

  15. GIS Themes • Used as spatial templates to define areal hydrologic settings • Identify Geomorphic Setting • Indicates the fluvial environment (e.g. hydric soils) • Landforms and landscapes • Water source and hydrodynamics • Direction of flow and strength of water movement • Layers ranked and combined at a landscape scale to provide a relative assessment of wetland equivalence

  16. Describe the Region (including HGM or wetland classes) Develop a Profile for Each HGM or Wetland Class Develop a List of Functions Develop a Functional Profile for Each HGM Class List Relevant & Appropriate Variables for Each Function Describe Each of the Variables Steps in the Procedure

  17. Prepare Rationale for Model Development Develop an Inventory Sheet Develop a Model for Each Function Modify Procedure for Other Regions Apply Procedure to Case Studies in Several Regions Fine Tune Procedure Based on Case Study Results Steps in the Procedure

  18. What should your assessment method do? • Rank wetland functions and values? • Assess interrelationships? • Assess regional significance? (Mapping) • Define watershed functions? • Database integration • Use good science (peer approved)

  19. Defines: HGM classes Identifies reference criteria Identifies reference standard reference standard subset Defines: What is functional and dysfunction? Should have local knowledge What attributes that can be screened using GIS or aerial photography? Technical Team

  20. 2-ft contour Hydric soils Closed depressions USGS blue-line streams Shape files of recorded floods 2-yr, 5-yr, 10-yr, 20-yr, 100-yr Existing info from land managers Geomorphology Regeneration distance NRCS farmed wetlands Stream buffers Public lands Permanent water Landscape factors Useful GIS Information

  21. Biological/Habitat Functions Wildlife Habitat/Floristic Diversity Stream and Lake Aquatic Habitat Water Quality/ Stormwater Storage Functions Shoreline and streambank stabilization Sediment and toxicant retention Nutrient removal and transformation Stormwater storage and hydrologic stabilization Important Functions

  22. High Quality Habitat Habitat and Floristic Quality/Diversity Irreplaceable Unmitigatable High state/local inventory score High Functional Value Functional value Several beneficial functions provided High Quality and High Value Wetlands

  23. Initial Screening Process • Existing inventories (state, county) • Aerial photo interpretation and scoring • Hydric soils • Size, shape characteristics • Physical Attributes and Indicators • Dependent on GIS, photo, map resolution • Positive and negative • Knowledge of local experts

  24. Initial Screening Process Purpose: • High functional vs. low functional • Indicators of Dysfunction

  25. Wildlife Habitat and Floristic Quality/Diversity Attributes • Drainage ditches (-) • Excavation (-) • Size (GIS) (+) • Physical intrusions and barriers (-) • Surrounding land use (+/-) • Habitat structure (+) • Vegetative and open water interspersion

  26. Aquatic Habitat LAKES STREAMS

  27. Water Quality and Stormwater Storage Functions Three mitigating functions present: • Sediment and toxicant retention • Nutrient removal and transformation • Stormwater Storage/Hydrologic Stabilization • Or critical size or juxtaposition in the landscape wrt to downstream resources

  28. Water Quality Mitigating Functions • Shoreline and streambank stabilization • Flowing water present • Sediment and toxicant retention • Nutrient removal and transformation • Stormwater Storage/Hydrologic Stabilization

  29. Shoreline stabilization Quality of buffer vegetation Wetland adjacency Wetland buffer width Sediment and toxicant retention Size Upstream of valuable aquatic resource Minimal outlet alteration Erect persistent vegetation Sediment accretion present Occasional flooding or ponding GIS Screening

  30. Nutrient Removal/ Transformation Upstream of valuable aquatic resource Non-riparian Minimal outlet alteration Ground cover vegetation in a low velocity environment Stormwater Storage/ Hydrologic Stabilization > 5 acres and 50% outside floodplain Non-riparian Minimal outlet alteration GIS Screening

  31. Watershed Setting “wetland remnants of the development process may not constitute the best configuration of wetland type for a watershed” “has implications for the kind of wetland planning that might be required in some …watersheds and …mitigation practices in those watershed” (NAS - Committee on Mitigating Wetland Losses)

  32. Watershed Setting Advanced Identification of Wetlands (USEPA, USACE, local agencies) • GIS screening tools • Aerial photographs • Field investigation

  33. Watershed Setting • Many wetland systems have been altered, severed, fragmented • Juxtaposition • Interrelationships • Flow patterns • Many wetlands not functioning in their historical (pre-settlement) context • How critical were interrelationships? • Our best guess must consider landscape

  34. Watershed Setting Advanced Identification of Wetlands • 4% of total # of wetlands in county designated as high habitat quality of biological functions (17,489 acres) • 17,489 acres of high habitat quality accounted for 42% of wetland acres • Approx. 10% of wetlands had notable watershed functions Your Project??

  35. Variables Plant species diversity Wetland juxtaposition Structure Conditions High, medium, low Connected  isolated  Pattern Functional ModelDiversity of Wetland Vegetation

  36. Example indicators (habitat diversity)

  37. General Condition Size Location Disturbance Functional score Known Attributes Quality indicators Functional indicators Imperilment Vulnerability Viability Database

  38. Thank you Brian Smith Biology/Water Quality Specialist FHWA – National Resource Center

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