01-14-2002 Council Packet - Laserfiche WebLink

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A-LONGL0003.00 Fire StatioB Wctlaad Mitigatioii Proposed Scope of Work and Timeline Wetland Mitigation As a requirement of the U.S. Army Corps of Engineers (USAGE), the Minnesota Wetland Conservation Act (WCA), and Minnehaha Creek Watershed District (MCWD), wetland impacts must be compensated for through the creation or restoration of new wetland. For the construction of the fire station, 8,480 square feet of wetland will be filled. Applying the 2:1 replacement requirement, a minimum of 16,960 square feet of replacement credit must be created or claimed. This will be accomplished through the creation of new wetland, upland buffer, and possible public value credit for storm water control ponds. All of these options will be done on site. Final evaluation and acceptance of credits for replacement will be at the discretion of the MCWD and the USAGE as both agencies have jurisdiction over the wetlands impacted by the project. The MCWD requires ty^ie for type wetland replacement. The existing wetland is a forested floodplain (Type I A) and will require that the mitigation site be designed as a wooded swamp with a scrub shrub understory. The location of the site will be along a drainage ditch with the main source of hydrology being seasonal flooding. These wetlands are difficult to design and develop, and will require considerably more time to design than a typical emergent mitigation site. Design and creation of wetland mitigation sites is a collaborative effort of many disciplines and requires close coordination between engineers, hydrologists, biologists, and ultimately the contractor responsible for construction. Described below is a draft scope and budget describing the tasks and estimated costs required to complete a mitigation site from initial site location to final grading and seeding. Hours have been summarized to reflect time spent for each task and personnel classification. A draft timeline has also been included to document the key dates when deliverable products are due. The plan is to submit a draft proposal to the MCWD by the end of January to receive preliminary approval. Please note that this draft proposal only includes the hours required to complete a mitigation plan. Project costs, including estimated cost for excavation, soil replacement, seeding, tree planting, etc., are not included with this scope. These costs will be estimated through the planning process and included as a final project cost at the time the mitigation plan is deemed complete. Wetland replacement also has additional requirements, including a five-year monitoring period and the implementation of a vegetation management plan. A separate scope and budget has been included for the monitoring requirement. The vegetation management plan will be drafted with the final mitigation design, but will commence with annual monitoring. Construction oversight has been incorporated with the monitoring plan. Task 1 - Determine Goal of Replacement The design of wetlands begins with a determination of how much wetland needs to be replaced, the function and values that need to be replaced, site geometry, and topographical setting. This task has been completed with the submittal of the initial wetland permit application.