After review of the stormwater management concept plan, and modifications to that plan as deemed necessary by the Town Council, a final stormwater management plan must be submitted for approval. The final stormwater management plan, in addition to the information from the concept plan, shall include all of the information required in the Final Stormwater Management Plan checklist found in the Stormwater Design Manual. This includes:
(A) Contact information. The name, address, and telephone number of all persons having a legal interest in the property and the tax reference number and parcel number of the property or properties affected.
(B) Topographic base map. A 1" = 200' topographic base map of the site which extends a minimum of 50 feet beyond the limits of the proposed development and indicates existing surface water drainage including streams, ponds, culverts, ditches, and wetlands; current land use including all existing structures; locations of utilities, roads, and easements; and significant natural and manmade features not otherwise shown.
(C) Calculations. Hydrologic and hydraulic design calculations for the pre-development and post-development conditions for the design storms specified in this chapter. Such calculations shall include:
(1) Description of the design storm frequency, intensity and duration;
(2) Time of concentration;
(3) Soil Curve Numbers or runoff coefficients;
(4) Peak runoff rates and total runoff volumes for each watershed area;
(5) Infiltration rates, where applicable;
(6) Culvert capacities;
(7) Flow velocities;
(8) Data on the increase in rate and volume of runoff for the design storms referenced in the Stormwater Design Manual; and
(9) Documentation of sources for all computation methods and field test results.
(D) Soils information. If a stormwater management control measure depends on the hydrologic properties of soils (e.g., infiltration basins), then a soils report shall be submitted. The soils report shall be based on on-site boring logs or soil pit profiles. The number and location of required soil borings or soil sits shall be determined based on what is needed to determine the suitability and distribution of soil types present at the location of the control measure.
(E) Maintenance and repair plan. The design and planning of all stormwater management facilities shall include detailed maintenance and repair procedures to ensure their continued function. These plans will identify the parts or components of a stormwater management facility that need to be maintained and the equipment and skills or training necessary. Provisions for the periodic review and evaluation of the effectiveness of the maintenance program and the need for revisions or additional maintenance procedures shall be included in the plan.
(F) Landscaping plan. The applicant must present a detailed plan for management of vegetation at the site after construction is finished, including who will be responsible for the maintenance of vegetation at the site and what practices will be employed to ensure that adequate vegetative cover is preserved. This plan must be prepared by a registered landscape architect or by the soil conservation district.
(G) Maintenance easements. The applicant must ensure access to all stormwater treatment practices at the site for the purpose of inspection and repair by securing all the maintenance easements needed on a permanent basis. These easements will be recorded with the plan and will remain in effect even with transfer of title to the property.
(H) Maintenance agreement. The applicant must execute an easement and an inspection and maintenance agreement binding on all subsequent owners of land served by an on-site stormwater management measure in accordance with the specifications of this chapter.
(I) Erosion and sediment control plans for construction of stormwater management measures. The applicant must prepare an erosion and sediment control plan for all construction activities related to implementing any on-site stormwater management practices.
(J) Other environmental permits. The applicant shall assure that all other applicable environmental permits have been acquired for the site prior to approval of the final stormwater design plan.
(Ord. 2006-10, passed 11-27-06)