02-23-2004 Council Packet - Laserfiche WebLink

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I'^5.3 Inventory and Assessment of Wetlands 5.3.1 Wetland Inventory As stated earlier, the City's objective is to protect, enhonce, and/or restore wetlands that may be directly affected by runoff os development and redevelopment occurs. Therefore, only those wetlands located within 20 feet of a proposed or existing stormwater outlet pipe were inventoried and mapped as part of the SWMP. This inventory also served os the base of information for development of other parts of the wetland management plan. The wetlands inventoried for this SWMP are listed in Appendix I and are shown on the SWMP System Map. 5.3.2 Stormwater Susceptibility Assessment The Guidance For Evaluating Urban Storm Water and Snowmelt Runoff Impacts To Wetlands was the source material for rating a wetland's susceptibility to runoff. Potential impacts associated with storm and meltwater runoff include fluctuation in water levels (bourTce) within the wetland, the duration of inundation at the varying bounce elevations, and the quality of the water being directed to the wetland. A given wetiand's susceptibility to ojnoff Is dependent on the wetland type, and the characteristics arxi quality of its plant community. As an example, a sedge meadow, which likes a particular hydrologic regime is much more susceptible than a floodplain forest, which depends on fluctuating levels of water associated with seasortal flooding Also, a wet meadow with a variety of grasses and flowers is more sensitive than one dominated by reed canary gross. The runoff susceptibility rating for each of the evaluated wetlands is indicated by color-coding on the system map. The ratings described in the guidance document are ❖ Highly Susceptible ❖ Moderately Susceptible ❖ Slightly Susceptible ❖ Least Susceptible. Further discussion on susceptibility and associated wetlarxl community descriptions, modified from the Guidance For Evaluating Urban Storm Water and Snowmelt Runoff Impacts To Wetlands, is presented in Appendix H. Each susceptibility rating category describes different wetland types, including plant commurtities and hydrology. OtyarOrono Surftct mter Manag&neri Plan 1 A