02-09-2010 Council Work Session Packet

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J��y z s, 2010 James Wisker MC WD Planner 18202 Minnetonka Blvd. Deephaven, NiN, 55391 Dear James: Please consider the following comrnents regarding proposed changes to the MCWD Rule D. The proposed revisions allow for wetland management class to be deternuned by the current version of the Minnesota Routine Assessment Method as an alternative to the use of the management class currently assigned to the wetland by the District's previous assessment. While the option to allow reevaluation of wetland functions utilizing the current version of MnRAM{Version 3.1)is a good idea, it will not automatically generate a management classification. Output from MnRAM provides ratings for each individual function{ie: high,medium, or low) but does not provide a recommended managernent classification. BWSR has developed a"Recommended Wetland Management Classification System"to use in conjunction with MnRAM,Version 3.0 currently in draft form and posted on their website(httn:l/www.bwsr.state.mn.us/wetlands/mnramlWetMgmtClass lvInRAM 3- 3.doc . If it is the intention of MCWD that the BWSR classification system would be utilized as an alternative to the currently assigned classification,it should be clearly specified. In addition,if the BWSR system is to be utilized,it should be in a final rather than draft form. If it is not the intention of MCWD to urilize the BWSR classification system, the proposed alternative classification system should be incorporated into the rules. While I support the proposed approach of a graduated buffer width based on wetland management classification, I believe the proposed buffer widths are generally wider than what is necessary to adequately protect wetlands from post-development degradation. Documentation provided by MCWD to justify proposed widths is inconsistent with recommended buffers, with the BATC study indicating effective nutrient and sediment remove by much narrower buffers, even with steep slopes. The EOR review and synthesis of buffer research indicated that quality 30-foot wide buffers consistently provided more than an 80 percent removal af TSS. Little or no increase of TSS removal was documented in buffers wider than 50 feet in the studies considered. Wiziie narrower buffers ca.n be overwhelmed by excessive sediment loads associated with the agricultural systems studied, such sediment loads would not occur in a fully revegetated, post- development landscape.