07/25/2007 Env Bd Packet - Laserfiche WebLink

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topography will be used to derive a "normal" water elevation for the basin for the purpose of computing the 100 -year elevation. (vi) All stormwater management structures and facilities must be designed for maintenance access and properly maintained in perpetuity to assure that they continue to function as designed. The maintenance responsibility must be memorialized in a document executed by the property owner in a form acceptable to the District and recorded on the deed. Altematively, a municipality that has provided for assuming the perpetual maintenance obligation in its District- approved local water management plan may do so in a writing signed by an official with authority. (vii) Before work under the permit is deemed complete, the permittee must submit as- builts demonstrating that at the time of final stabilization, stormwater facilities conform to design specifications. 4. REQUIRED EXHIBITS. The following exhibits must accompany the permit application. One set, full size (22 inches by 34 inches); two sets, reduced to maximum size of 11 inches by 17 inches. (a) A Storm Water Pollution Prevention Plan. (b) Property lines and delineation of lands under ownership of the applicant. (c) Delineation of the subwatershed contributing runoff from off -site, proposed and existing subwatersheds onsite, emergency overflows, and drainageways. (d) Geotechnical analysis including soil borings at all proposed stormwater management facility locations. (e) Proposed and existing stormwater facilities' location, alignment and elevation. (f) Delineation of existing on -site wetland, marshes, shoreland and/or floodplain areas. (g) Identification of existing and proposed normal, and ordinary high and 100 -year water elevations on -site. (h) Identification of existing and proposed site contour elevations related to NGVD, 1929 datum. (1) Construction plans and specifications of all proposed stormwater management facilities, including design details for outlet control structures. (j) Stormwater runoff volume and rate analyses for the two- and 100 -year critical events, pre - settlement and proposed conditions. (k) All hydrologic, water quality, and hydraulic computations completed to design the proposed stormwater management facilities. (1) Narrative addressing incorporation of infiltration BMPs. (m) Platting or easement documents showing conveyance to the local land use authority of drainage and flowage easements over stormwater management facilities, stormwater conveyances and on -site floodplain up to the 100 -year event. An easement on a public ditch must be a minimum of 33 feet each side of centerline and specify a District right of enforcement to that minimum width. (n) Narrative explaining BSD techniques that were evaluated during the development of the design for the project, the results of the evaluation of each and, for any techniques that were deemed infeasible, the reasoning for the determination. DRAFT DOCUMENT 14 • • •