Jon Kusler Association of State Wetland Managers ; Report available at:

Transcription

1 Assessing Floodplain Natural and Beneficial Functions Jon Kusler Association of State Wetland Managers ; Report available at:

2 Content of Presentation Overview: Natural and Beneficial Functions Some Observations Concerning Techniques for Assessing Natural and Beneficial Functions

3 ASWM BACKGROUND Three-year series of studies of Wetland Assessment which resulted in the following reports available at Wetland Assessment in the Courts Wetland Functions and Values Integrating Wetland Assessment Into Regulatory Permitting Reconciling Wetland Assessment Techniques Supplemental research and writing was funded by the McKnight Foundation which is gratefully acknowledged.

4 Workshops and Symposia 1985 National Wetland Assessment Symposium, Portland, Maine 1996 HGM Workshop, Washington, D.C National Wetland Assessment Symposium, Annapolis, Maryland 1998 Workshop: Selecting and Using Reference Sites, Millbrook, New York 1998 Workshop: Landscape Level Wetland Assessment, Arlington, Virginia 2001, 2002, 2003 Stream Restoration Training Workshops, Fairlee, Vermont; Bear Mountain, New York; Albuquerque, New Mexico; Socorro, New Mexico 2003 Seminar: Reconciling and Applying Wetland Assessment Techniques for Streams and Other Ecosystems, Washington, D.C National Symposium: Landscape Scale Wetland Assessment and Management, Concord, New Hampshire 2005 Workshop: Reconciling Assessment Techniques For Riverine Wetlands, Streams, Riparian Areas, and Floodplains, Amherst, Massachusetts

5 Floodplain, Wetland, Riparian Area Natural and Beneficial Functions and Values Flood storage. Flood conveyance. Wave reduction. Erosion control. Habitat for fish, shellfish, waterfowl, many types of endangered species. Sediment reduction in lakes, reservoirs, streams, estuaries, and coastal systems. Pollution prevention and treatment: prevent pollution from entering a water body. treat (remove) pollution in a water body. Natural crops and timber: cranberry, blueberry, saltmarsh hay, aquaculture species, wild rice, forestry, other natural crops. Groundwater recharge.

6 Scenic beauty, aesthetics. Recreational opportunities, ecotourism. Historical, archaeological, heritage, and cultural opportunities. Education and research. Trapping of carbon, carbon stores important to moderation of global warming. Micro-climate modification.

7 Wave Attenuation, Erosion Control

8 Hurricane Camille, Foot Storm Surge and Waves

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10 December, 2004 South Asian Tsunami

11 Even a Narrow Band of Wetland May Cause Waves to Break by Increasing Friction and Absorbing Energy

12 Extensive Wetlands Reduce Surge and Tsunami Elevations. 1 Foot per 1.0 to 2.7 Miles of Wetland

13 Flood Storage (Headwater wetlands and floodplains are important.)

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17 Flood Conveyance (Zero Rise Floodway in Tulsa)

18 Recreation: (Multiobjective Greenways: Floodplain, Wetland, Riparian Areas)

19 Open Space Uses Can Often Serve a Variety of Community Recreation Needs While Reducing Flood Losses

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21 Orlando Wetland Festival

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23 Pollution Prevention and Control (Buffers in the Chesapeake Watershed)

24 Pollution Prevention and Control: Restore Or Create Wetlands In New Stormwater Management Facilities; Retrofit Existing Stormwater Management Facilities

25 Habitat: (Restoration Beads Along the Missouri)

26 Habitat for Rare and Endangered Species (Vernal Pools in Placer County, California, Placer County Land Trust)

27 Aesthetics

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30 Timber Production (Forested Wetlands)

31 Research (Elkhorn Slough, Elkhorn Slough Foundation, California)

32 Education (High School Students Participating in Tampa Bay Restoration Project)

33 Some Observations: Techniques for Assessing Natural and Beneficial Functions Jon Kusler Association of State Wetland Managers

34 TECHNIQUES VARY CONSIDERABLY What is assessed: Natural processes ( functions )? goods and services? Condition? economic value? Other? For what purpose and audience? Flood loss reduction project Regulatory permitting Impact reduction Mitigation At what scale, degree of accuracy? How is information processes? Manual manipulation of data Computerized manipulation (e.g., GIS) Products: Maps? Graphic displays? Written reports? Costs, level of staff expertise required?

35 Simple Field Surveys

36 Wetland/Stream/Riparian Reference Sites

37 FLOODPLAIN CHARACTERISTICS IMPORTANT TO THE CAPACITY OF FLOODPLAINS TO PRODUCE GOODS AND SERVICES (NATURAL AND BENEFICIAL FUNCTIONS) Overall hydrologic and geologic setting including climate, rainfall, topographic form, geology, soils. Fluvial processes and geomorphology: the erosion and depositional processes which determine the vertical and lateral position of the waterbody relative to the floodplain. Overall ecological setting including adjacent upland and deep water habitats. Onsite hydrologic and hydraulic characteristics including fluctuations in water levels, hydroperiod. Water quality, water chemistry (e.g., Ph), nutrients. Flora (vegetation): types, diversity of types, condition. Fauna (animals): types, diversity of types, condition. Persistence, longevity of the floodplain and floodplain features (i.e., will a wetland be here in 10 years?) "Connectivity" with other wetlands, waters, upland habitat. Size and shape (e.g., edge ratio). Existing uses and alterations and restoration potential. Presence or absence of buffers. Presence or absence of active management measures. (e.g., exotic weed control, water level control, fencing of cattle, etc.)

38 FLOODPLAIN ASSESSMENT Wetland Assessment Models. River and Stream Assessment Models. Riparian Area Wetland Assessment Models

39 EXAMPLES OF BROADLY KNOWN TECHNIQUES FOR WETLANDS, RIPARIAN AREAS, RIVERS AND STREAMS IBI (Indices of Biological Integrity) HGM (Hydrogeomorphic Assessment Technique) WET (Wetland Evaluation Technique) Proper Functioning Condition Rosgen et al.

40 MODELS FOR ASSESSING FUNCTIONS Models and methods for assessing functions may be broadly grouped in three overlapping categories which share characteristics but differ in their foci: Models for assessing floodplain/wetland natural process (e.g., denitrification), Models for assessing the potential of floodplains to produce goods and services (e.g., pollution control), and Models for assessing floodplain/wetland condition (e.g., unaltered, partially altered, substantially altered).

41 INFORMATION NEEDS for a PROCESSES EVALUATION APPROACH Identification of natural processes needed to produce specific functions such as geologic erosion and deposition processes and the growth of vegetation retarding runoff producing flood storage. Measurement of processes in the specific circumstances. Conduct of various types of analyses of processes (e.g., determination of value in some circumstances).

42 HAS THE SILVER BULLET FOR WETLAND, RIVER, RIPARIAN AREA, FLOODPLAIN ASSESSMENT BEEN FOUND? Considerable interest among regulators/land managers in improved methods Over 40 rapid wetland assessment methods alone developed by 1999 (Bartoldus, 1999) and many more since then. Most ostensibly have been developed to aid regulators/land managers. Little use of any method by regulators other than some use of HEP, WET spin-offs and New England Highway Methodology. Some use of IBI and other condition assessments (e.g., Ohio). Search for the silver bullet continues.

43 SOME COMMON DENOMINATOR STEPS IN ASSESSMENT 1. Defining the Assessment Area 2. Determining Floodplain Functions on a Preliminary Basis Wetland Assessment Models. River and Stream Assessment Models. Riparian Area Wetland Assessment Models 3. Determining Floodplain Functions on a More Detailed, Accurate Basis (If Needed) 4. Assessment of Social Significance, Worth, Value Models include: Models providing economic dollar values for floodplain functions. Models providing a nominal description of functions. Techniques to estimate the social significance of functions without providing a quantitative, monetized analysis of functions.

44 PROBLEM: COST (IN STAFF AND DOLLARS) IS OFTEN TOO HIGH FOR THE VALUE OF INFORMATION DEVELOPED The issue is not whether information developed by an assessment/monitoring model is of some interest and some value. It is the cost of gathering and analyzing the information in comparison with the costs of gathering other types of information and relative degree of need for both types of information.

45 NEVERTHELESS, CONSIDERABLE EXPERIENCE HAS BEEN GAINED WET Developed by the Corps with the Federal Highway Administration and many others in the early 1980 s. Six states developed baby WETs. Looked at capacity, opportunity and social significance. Rated and ranked individual function. Complicated and fairly time consuming. Was not responsive to different wetland types or to regional differences in wetlands. Quite subjective. Did not provide an adequate basis for determining mitigation ratios. HGM Starting in 1994, developed by the Corps with much help from EPA, NRCS other agencies. Many millions of dollars spent on models. Used a new definition for function. Classifies wetlands by hydrogeomorphic setting. Uses reference. In 1996 Federal Agencies set a goal in the Federal Register. HGM was to be used on 80% of the 404 permits within two years. After thirteen years, HGM is not being used in any systematic way in any regulatory context. Complicated, hard to understand, basic premises not tested. Many states have made some use of HGM. Washington adopted HGM models, many others have incorporated some measure of HGM into their programs. However no one has adopted HGM per se.

46 IBI (Indices of Biological Integrity) Developed primarily by EPA but with help from other agencies Uses reference Biologically and botanically based Measures relative condition Many states have investigated use, ongoing development Progress in developing effective models has been slow Used for streams; development and use for wetlands is proving much more difficult Other New England District Highway Methodology GIS

47 RECOMMENDATIONS, OBSERVATIONS Multiple levels of assessment are needed Both broad brush and detailed assessment approaches are needed No single assessment technique is going to fill all needs Both site-specific and watershed approaches are needed Condition assessments are useful, but so are functional assessments Assessment approaches can reduce the use of professional judgment but cannot avoid it altogether. Subjectivity and arbitrariness can be reduced.

48 NEED TO UTILIZE TECHNIQUES FOR COPING WITH LIMITED BUDGETS, SMALL STAFFS, AND LIMITED EXPERTISE Require Landowners to Develop Much of the Required Information for Mid-sized and Larger Projects Use Presumptions Use Red Flagging, Yellow Flagging, Focusing, Screening, Scoping, and Other Filtering Mechanisms Combine Broad, Generalized, Up-front Data Gathering With Selective Site-Specific Surveys Use Surrogates Make Simplifications; Omit Consideration of Some Factors

49 Report available at: