Primary purpose
To assess wetland functions in routine local, state, and federal permit applications, and for wetland planning assessment.
Expertise needed
Trained and experienced wetland professionals (preferably a diverse team).
Applicable habitat types
Wetlands in Minnesota.
Categories assessed
Nine functions are addressed: vegetation diversity/integrity; maintenance of hydrologic regime; flood/stormwater attenuation; water quality protection; shoreline protection, wildlife habitat; fishery habitat; aesthetics/recreation/education/cultural; and commercial uses.
Procedure
The user(s) reviews existing data sources, visits the area, and answers questions that indicate the presence of factors important for each function. There are no models. The answers to questions and explanations in the user guidance sections are used as a guide in rating the capability of a wetland to provide a function compared to a reference wetland in the same wetland comparison domain. Possible functional level ratings include: low; medium; high; exceptional; and not applicable.
Key Terminology
Function: physical, chemical, or biological process or attribute of a wetland.
Functional level: definition not provided.
Reference wetland: a wetland judged to have the highest level of overall sustainable functional capacity (based on a classification system such as Circular 39, Cowardin/NWI, or HGM ) within the wetland comparison domain.
Value: the extent to which a wetland function is perceived as beneficial to an individual or society.
Wetland comparison domain: geographic area (e.g., political boundary, major or local watershed boundary, or ecoregion subsection) used for functional comparison.
Output
Measure of functional level of a site relative to reference wetlands within the same wetland comparison domain.
Estimated time to assess 1 acre site
Total 2-3 hours per site.
2-3 hours: Complete general information (step 1), assess wetland functions (step 2), and record results (step 3).
Comparison of habitat types
Can directly compare wetlands of the same type within the same wetland comparison domain.
Use as guide to design
MNRAM should not be used as a guide to design. It is not the intended purpose for the procedure. For example, MNRAM uses opportunity variables (questions), but does not set upper limits on those opportunities that could potentially reduce the functional level (e.g., significant nutrient and/or sediment loads to the wetland from surrounding or upstream land uses is considered a preferred condition for the water quality protection function). In some circumstances, a wetland may not have the capacity to remove all nutrient input. An upper limit on the opportunity must be defined to insure that the existing or planned wetland can predictably have the capacity to provide a function. Also, MNRAM does not provide validated threshold values for many variables. Another aspect to consider is whether the model can provide explicit design criteria. The design criteria for this function would be not be explicit or may require the presence of fauna which cannot be controlled (e.g., design for a presence of native fish species). A high degree of professional judgement is used to assign a rating since there is no model. Unless the reasons for assigning a high score are documented, it would be difficult to determine which variables or other information should be incorporated into the design to maximize function.
Contact person
John Jaschke, Minnesota Board of Water & Soil Resources, One West Water Street, Suite 200, St. Paul, MN 55107 phone: (651) 297-3432; fax: (651) 297-5615; e-mail: john.jaschke@bwsr.state.mn.us
Related procedures
MNRAM is based on WI RAM (WI DNR 1992), but modified to incorporate concepts from the HGM Approach (Smith et al. 1995).
Extent of use/field testing
MNRAM has undergone field testing during the development stage and a limited number of training sessions for local governments. Future testing will be done to assess its value for regulatory permit decision making and planning. Comparisons to other methods will also be part of future field testing work. With respect to use, MNRAM has been applied to wetland planning (e.g., prioritizing and assessing wetlands for ordinance protection), and controversial projects where mitigation is proposed. The extent of use is unknown, but estimated at about 100 times over the last two years.
Proposed future revisions
Final version 2.0 expected in July 1998.
Key Reference
Minnesota Board of Water and Soil Resources. 1998. Minnesota Routine Assessment Method for Evaluating Wetland Functions (MNRAM) Draft version 2.0. Minnesota Board of Water and Soil Resources, St. Paul, MN. 39 pp.