In the preparation of a surface water management plan, the following general principles shall be adhered to:
A. 
The rate and velocity of runoff from the site following completion of the planned development shall not exceed that which would prevail under total coverage in a meadow of good hydrologic conditions (permanent meadow), as defined by Soil Conservation Service standards, or previous cover, whichever produces the least amount of runoff.
B. 
Maximum use shall be made of presently existing surface water runoff control devices, mechanisms or areas, such as existing berms, terraces, grass waterways, favorable hydrologic soils, swamps, swales, watercourses, woodlands, floodplains, as well as any proposed retention structures.
C. 
Evaluation shall be made of the nature of the subwatershed of which the site is a part, the receiving stream channel capacities and point of concentration structures as shown on the base maps showing roads, streams, culverts and bridges and described in a report entitled "Stormwater Management Study,'' June 1, 1973.
D. 
Surface water runoff shall not be transferred from one watershed to another.
E. 
The plan shall coordinate with the soil erosion-sediment control plan, and the Critical Area Ordinance and Tree Protection Ordinance provisions shall be adhered to where applicable.
F. 
To the greatest possible extent, the plan shall avoid the concentration of flow and shall provide for dissipation of velocities at all concentrated discharge points.
G. 
Reestablishing vegetative cover shall be in accordance with Standards and Specifications for Soil Erosion and Sediment Control in New Jersey, adopted by the Hunterdon County Soil Conservation District, latest edition.
H. 
Timing for the plan shall establish permanent surface water management measures prior to construction or other land disturbance, including seeding and establishing sod or grass waterways.
Design standards for engineering review by the Township Engineer shall be as follows:
A. 
For calculating runoff controls, either of the following methods may be used in computing runoff: Soil Conservation Service Method under the United States Department of Agriculture or the Rational Method.
Criteria
SCS Method
Rational Method
Surface conditions
Meadow
Average cultivation or light growth, r = 0.20 to 0.40
Collection system
15-year storm
15-year storm
Storage
100-year storm
100-year storm
Outlet discharge
10-year storm
10-year storm
Emergency spillway
100-year storm
100-year storm
Soil type
A, B, C, D as determined by map (Hydrologic Soils)
Loam
Maximum velocity at pipe outlets
4 feet per second
4 feet per second
Intensity
SCS Method
Water policy rainfall curves
B. 
All outfalls are to be designed in a manner to retard velocities at the outfall and provide stream channel protection.
C. 
When a natural drainage pattern is necessarily intercepted, as by a street, this shall be considered.
D. 
All structures and land treatment practices shall conform to Standards and Specifications for Soil Erosion and Sediment Control in New Jersey, latest edition, adopted by the Hunterdon County Soil Conservation District.
E. 
All water-carrying structures and/or retention areas shall be completed and stabilized prior to diversion of water to them.
F. 
As preliminary to developing the surface water management plan, there shall be an inventory of the site showing all existing natural and man-made drainage-related features as listed in § 316-12B (berms, terraces, grass waterways, favorable hydrologic soils, poorly drained soils, swamps, swales, watercourses, woodlands, floodplains). These shall be incorporated into the plan to the greatest possible extent in accordance with their functional capability.
G. 
Drainageways and watercourses which normally carry or receive surface water runoff shall not be overloaded with increased runoff, sediment or other pollution resulting from disturbance of soil and vegetation or incident to development, construction or other activity.
H. 
Due consideration shall be given to the relationship of the subject property to the natural or established drainage pattern of the subwatersheds of which it is a part as shown on any applicable map of the Watersheds Overlay, Franklin Township, Stormwater Management Study, June 1, 1973.
I. 
Surface water runoff controls shall be designed to assure that the land in question uses no more than its proportionate watershed share of the natural stream and culvert capacity as set forth in the tables, Appendix C, Stormwater Management Study, June 1, 1973, or as ascertained by field measurements.
J. 
The curbing requirement may be relaxed by the Township Engineer in the interest of acceptable drainage accommodation that will relieve concentration of flow or discharge to a stormwater sewer system.
K. 
Innovative surface water runoff control and recharge devices may be proposed, such as rooftop storage, dry wells, cisterns, roof drain infiltration trenches, provided that they are accompanied by detailed engineering plans and performance capabilities.
A. 
The applicant shall submit a separate surface water management plan for any proposed lot, subdivision, cluster development, site plan review, special exception, conditional use, zoning variance or any land disturbance activity except as exempted in §§ 316-7 and 316-8. The surface water management plan shall be coordinated with the soil erosion and sediment control plan required by Chapter 290, Soil Erosion and Sediment Control.
B. 
Such plan shall contain:
(1) 
Lot and block numbers of the site as shown on the current Tax Map of the Township.
(2) 
Name and address of the owner of the land.
(3) 
Size of subwatershed and the location of the site within the subwatersheds.
(4) 
Location, description and quantification of significant natural and man-made features on and surrounding the site, including topography, all impervious surfaces, soil and drainage characteristics, with particular attention to the location and description of presently existing surface water runoff control devices, mechanisms or areas, swamps, floodplains, swales, woods and vegetation, steep slopes and other features critical to the purposes of this chapter.
(5) 
Size of nearest culvert or bridge downstream of discharge area, profiles and cross section of stream channel upstream of that structure as well as profiles and cross sections of stream channel at all points of proposed surface water discharge from the site as required by the Township Engineer.
(6) 
Location, description and quantification of proposed changes to the site, whether of a permanent or temporary nature, with particular attention to impervious surfaces and interception of presently dispersed flow which may impact upon the capacity of the soil, vegetation cover and drainageways to absorb, retard, contain or control surface water runoff.
(7) 
Designation of critical or other areas to be left undisturbed shall be shown in sufficient detail to be accurately marked on the land.
(8) 
Computation of the total surface water runoff before, during and after the disturbance of land and/or construction of impervious surfaces.
(9) 
Proposed measures for surface water management.
(10) 
A schedule of the sequence of installation of the surface water management structures, stipulating current maintenance, continued maintenance and responsibility for same.
(11) 
Proposed maintenance schedule for all surface water management structures, stipulating current maintenance, continued maintenance and responsibility for same.
(12) 
All proposed revisions of required data as well as such additional data as the Land Use Board may require.