06-30-14-WS - Laserfiche WebLink

Home Browse Search

),, AVAILABLE ALTERNATIVES THAT WERE CONSIDERED MINIMIZE OR MITIGATE ENVIRONMENTAL .D EFFECTS TO WETLANDSISCUSS WHETHER ANY REQUIRED COMPENSATORY WETLAND MITIGATION , FOR UNAVOIDABLE WETLAND IMPACTS WILL OCCUR IN THE SAME MINOR OR MAJOR WATERSHED . AND IDENTIFY THOSE PROBABLE LOCATIONS Impacts: Given the scattered location of the site wetlands and the absence of a mass grading plan, the specific extent of wetland impacts cannot be estimated. Therefore, for purposes of this evaluation it was assumed that all 14.4 acres of wetland identified on the site would be considered waters of the US and under US Army Corps of Engineers (USACE) jurisdiction, and under the jurisdiction of the Rice Creek Watershed District as the local government unit under the Wetland Conservation Act. It was assumed for this analysis that all wetlands would be impacted by site development. However, some wetland may be preserved within the proposed site green space . Mitigation Requirements: Based on compatible needs (wetlands need a water source, stormwater management needs a receiving area), the stormwater management areas and wetland replacement would be combined to the extent possible under current regulations. There are a number of constraints (topography, site grading) and challenges (staging of development) that will need to be addressed in order for these functions to work on-site and work together. The County and City are currently in the planning stage to design the regional stormwater/wetland mitigation plan. The USACE and Wetland Conservation Act (WCA) mitigation requirements are similar. The USACE oversees Section 404 of the Clean Water Act and Rice Creek Watershed District implements the WCA or MN Rule 8420. Wetland impacts are assumed to be replaced at a 2:1 ratio, meaning for every 1 acre of wetland impacted by the project, 2 acres will either be created or wetland credits will be purchased from a state wetland bank. Given the site constraints, it is anticipated that approximately half (1:1 ratio) of wetland impacts would be replaced on site with the other half being replaced off-site by purchasing credits from the state wetland bank. The current WCA requirements for on-site project specific replacement is any new wetland created onsite would receive 75% credit. This means that to reach 14.4 acres of onsite replacement, 19.2 acres of wetland would be required along with upland buffers. This amount could be decreased if not all the wetland is impacted, or not all the wetland is jurisdictional, or if RCWD allows more replacement within the adjacent Rice Creek parklands or other off-site locations. The purchase of off-site wetland credits would include 14.4 acres. The wetland bank sites where these credits will be withdrawn from would be required to be located in the same Bank Service Area (BSA 7) and major watershed 20 (Mississippi River (Metro)). b) O-D THER SURFACE WATERSESCRIBE ANY ANTICIPATED PHYSICAL EFFECTS OR ALTERATIONS TO (,,,, SURFACE WATER FEATURESLAKES STREAMS PONDS INTERMITTENT CHANNELS /),,,, COUNTYJUDICIAL DITCHES SUCH AS DRAINING FILLING PERMANENT INUNDATION DREDGING ,,,. DIKING STREAM DIVERSION IMPOUNDMENT AQUATIC PLANT REMOVAL AND RIPARIAN ALTERATION D ISCUSS DIRECT AND INDIRECT ENVIRONMENTAL EFFECTS FROM PHYSICAL MODIFICATION OF .I,, WATER FEATURESDENTIFY MEASURES TO AVOID MINIMIZE OR MITIGATE ENVIRONMENTAL ,-BMP EFFECTS TO SURFACE WATER FEATURES INCLUDING INWATERESTANAGEMENTRACTICES / THAT ARE PROPOSED TO AVOID OR MINIMIZE TURBIDITYSEDIMENTATION WHILE PHYSICALLY .D ALTERING THE WATER FEATURESISCUSS HOW THE PROJECT WILL CHANGE THE NUMBER OR TYPE June 2014– Final AUAR14