[Ord. No. 564, 9-6-2000]
A.
Drainage for all developments, whether residential or nonresidential, shall be provided in accordance with the standards set forth at N.J.A.C. 5:21, the Residential Site Improvement Standards (RSIS).
B.
All lots shall be graded to secure proper drainage away from the buildings. Additionally, drainage shall be provided for all lots in a manner consistent with the RSIS which will prevent the collection of stormwater in pools or other unauthorized concentrations of flow, and, to the greatest extent possible, water shall not flow across adjacent property lines.
C.
A final drainage plan shall accompany the final subdivision or site plan. Such drainage plan shall show the same information as required on the preliminary plan with the addition that the individual lot grading shall be shown as follows:
(1)
Final grades shall be shown for each corner, all high and low points and breaks in grade, finished floor elevations of structures, finished grades of septic systems, if applicable, and at the corners of tentative structure locations. If the use of drainage swales is intended, the elevation of these swales shall be shown. The minimum grade of disturbed areas shall be 1.5%. Prior to construction of foundation walls, an as-built plan of the horizontal and vertical location of the foundation footing shall be submitted to the Zoning Officer for review and approval. As a condition precedent to the issuance of a certificate of occupancy for any lot in the development, the developer or building contractor shall submit an as-built lot grading plan to the Borough bearing an engineer's certification that the lot grading complies with the approved final lot grading and soil erosion and sediment control plans for the development.
D.
Detention and retention basins for single-family residential, non-cluster subdivisions shall be constructed on a separate lot specifically reserved for such purpose, which lot shall be dedicated to the Borough. Detention and retention basins for cluster and multifamily residential developments shall be located in the common open space to be maintained by the homeowners' association or property owner(s). Detention and retention basins in nonresidential developments shall be owned and maintained by the property owner(s).
E.
Regional detention or retention basins utilized by several property owners within a drainage basin are encouraged, and the feasibility of such joint facilities shall be examined by the applicant and reported upon to the Borough Engineer.
F.
Approval of new or replacement drainage structures shall be obtained from all required Borough, county, state and federal agencies and offices. Each applicant shall make appropriate application to the NJDEP, the Hunterdon County Planning Board, the Hunterdon County Soil Conservation Service and the Borough Engineer. Final approval shall not be effective until letters of approval from the proper governmental authorities shall be furnished to the Board with a copy of each letter forwarded to the Borough Engineer.
G.
When required by the Borough, and as indicated on an approved development plan, a drainage right-of-way easement shall be provided to the Borough where a tract or lot is traversed by a watercourse, surface or underground drainageway or drainage system, channel or stream. The drainage right-of-way easement shall conform substantially with the lines of such watercourse and, in any event, shall meet any minimum widths and locations as shown on any adopted Official Map or Master Plan. Such easement shall be expressed on the plat as follows: "Drainage easement granted for the purposes provided and expressed in the Land Use Ordinance of Frenchtown Borough."
H.
For all developments requiring site plan, subdivision, conditional use and/or variance approval, the applicant shall provide a computation of the additional peak rate of runoff anticipated from the site as a result of the approval of the proposed site plan, subdivision, conditional use and/or variance, using the methodologies set forth in the RSIS.
I.
All developments, whether residential or nonresidential, requiring site plan, subdivision, conditional use and/or variance approval shall provide for on-site storage and controlled release of stormwater as regulated by the RSIS for any increase in the rate of stormwater runoff anticipated.
J.
The applicant shall also document the anticipated impact that the additional runoff will have upon existing drainage structures located between the site and the downstream facilities and structures. If necessary, the applicant shall be required to make improvements to those structures to accommodate the additional runoff.