Sidewalks shall be four inches thick except at points of vehicular crossing where they shall be at least six inches thick. At vehicular crossings, sidewalks shall be reinforced with welded wire fabric mesh or an equivalent.

Concrete sidewalks shall be Class C concrete, having a twenty-eight day compressive strength of 4,500 p.s.i. Other paving materials may be permitted depending on the design of the development.

Graded areas shall be planted with grass or treated with other suitable ground cover and their width shall correspond to that of sidewalks.

Bicycle Paths. Dimensions and construction specifications of bicycle paths shall be determined by the number and type of users and the location and purpose of the bicycle path. A minimum eight foot paved width should be provided for two-way bicycle traffic and a five foot width for one-way traffic.

Bicycle Lanes. Lanes shall be four feet wide, or wide enough to allow safe passage of bicycles and motorists.

Bicycle-safe drainage grates shall be used in the construction of all residential streets.

Minimum street grade permitted for all streets shall be 0.5%; but streets constructed at this grade shall be closely monitored and strict attention paid to construction techniques to avoid ponding. Where topographical conditions permit, a minimum grade in excess of 0.75% shall be used.

Maximum street grade shall be 8%.

Minimum intersection angle. Street intersections shall be as nearly at right angles as possible and in no case shall be less than 75°.

Minimum centerline offset of adjacent intersections. New intersections along one side of an existing street shall, if possible, coincide with any existing intersections on the opposite side of each street. Use of "T" intersections in subdivisions shall be encouraged. To avoid corner-cutting when inadequate, offsets exist between adjacent intersections, offsets shall be at least between 175 to 200 feet between centerlines.

Minimum curb radius. Intersections shall be rounded at the curbline, with the street having the highest radius requirement as shown in Exhibit 8[1] determining the minimum standard for all curblines.

Grade. Intersections shall be designed with a flat grade wherever practical. Maximum grade within intersections shall be 5% except for collectors which shall be 3%.

Minimum centerline radius; minimum tangent length between reverse curves; and curb radii. Requirements shall be as shown in Exhibit 8[2].

Sight triangles. Sight triangle easements shall be required and shall include the area on each street corner that is bounded by the line which connects the sight or "connecting" points located on each of the right-of-way lines of the intersecting street. The planting of trees or other plantings or the location of structures exceeding 30 inches in height that would obstruct the clear sight across the area of the easements shall be prohibited; and a public right-of-entry shall be reserved for the purpose of removing any object, material or otherwise, that obstructs the clear sight.

The distances shown in Exhibit 9[3] between the connecting points and the intersection of the right-of-way lines shall be required.

Pavement design for local and collector streets and parking areas shall adhere to the following specifications for their full paved area as shown on Exhibit 10[4].

Size type, and installation of hydrants shall be in accordance with local practice, or shall conform to the American Water Works Association standard for dry barrel hydrants (AWWA C-502). Hydrants shall have at least three outlets; one outlet shall be a pumper outlet and other outlets shall be at least 2 1/2 inch nominal size. Street main connections should be not less than six inches in diameter. Hose threads on outlets shall conform to National Standard dimensions. A valve shall be provided on connections between hydrants and street mains. All pipe, fittings, and appurtenances supplying fire hydrants shall be AWWA- or ASTM-approved.

All fire hydrants shall conform to the colorcode system as shown in Exhibit 12[6].

Watershed storm water management requires the determination of two runoff parameters: runoff peak rates of discharge and runoff volume. Both parameters shall be used in the comparison of predevelopment and post-development conditions.

Peak rate of discharge calculations shall be used to determine the configurations and sizes of pipes, channels, and other routing or flow control structures. Runoff volume calculations shall be used to determine the necessity for, and sizing of, detention and retention facilities.

Runoff peak rate of discharge calculation. The peak rate of runoff for areas of up to 1/2 of a square mile shall be calculated by the Rational Method or derivatives. The equation for the Rational Method is:

Runoff volume calculation.

A system emphasizing a natural as opposed to an engineered drainage strategy shall be encouraged.

The applicability of a natural approach depends on such factors as site storage capacity, open channel hydraulic capacity, and maintenance needs and resources.

Hydraulic capacity for open channel or closed conduit flow shall be determined by the Manning Equation, or charts/nomographs based on the Manning Equation. The hydraulic capacity is termed Q and is expressed as discharge in cubic feet per second. The Manning Equation is as follows:

Velocities in open channels at design flow shall not be less than five-tenths foot per second and not greater than that velocity which will begin to cause erosion or scouring of the channel. Permissible velocities for swales, open channels and ditches are shown in Exhibit 17[11].

Velocities in closed conduits at design flow shall be at least two feet per second but not more than the velocity which will cause erosion damage to the conduit.

Pipe size shall be dictated by design runoff and hydraulic capacity.

Hydraulic capacity shall be determined by the Manning Equation, except where appropriate, capacity shall be based on tailwater analysis and one-year high tide.

In general, no pipe size in the storm drainage system shall be less than 15 inch diameter. A twelve-inch diameter pipe will be permitted as a crossdrain to a single inlet.

All discharge pipes shall terminate with a precast concrete or corrugated metal end section or a cast-in-place concrete headwall with or without wingwalls as conditions required.

Materials used in the construction of storm sewers shall be constructed of reinforced concrete, ductile iron, corrugated aluminum, or corrugated steel. The least expensive materials shall be permitted unless site and other conditions dictate otherwise. Specifications referred to, such as ASA, ASTM, AWWA, etc., should be the latest revision.

Inlets, catch basins and manholes shall be designed in accordance with State Highway Department Standard Plans and Specification. Frame and grates shall be Campbell Foundry Company Pattern No. 2617 Bicycle Grates with stream-flowing grating, or equal.

Inlet spacing shall be designed to limit gutter flow width to six feet but shall not be more than 400 feet.

Manhole spacing shall be increased with pipe size.

Manholes shall be precast concrete, brick or concrete block coated with two coats of portland cement mortar.

If precast manhole barrels and cones are used, they shall conform to ASTM Specification C-473 with round rubber gaskets joints, conforming to ASTM Specification C-923. Maximum absorption shall be 8% in accordance with ASTM Specification C-478, method A.

If precast manholes are utilized, the top riser section shall terminate less than one foot below the finished grade and the manhole cover shall be flush with the finished grade.

Manhole frames and covers shall be of cast iron conforming to ASTM Specification A-48 Class 30 and be suitable for H-20 loading capacity. All manhole covers in rights-of-way or in remote areas shall be provided with a locking device. The letters "Year 19_____" and the words "Storm Sewer" shall be cast integrally in the cover.

Development shall use the best available technology to accommodate storm water management by natural drainage strategies as indicated in this section.

Nonstructural management practices, such as open space acquisition, stream encroachment and flood hazard controls shall be coordinated with detention requirements. Changes in land use can often reduce the scope and cost of detention provisions required by means of appropriate change in runoff coefficients.

Detention and all other storm water management facilities shall conform to the standards under the New Jersey Storm Management Act, N.J.S.A. 40:55D-1 et seq.

Where detention facilities are deemed necessary, they shall accommodate site runoff generated from two-, ten-, and 100-year storms considered individually, unless the detention basin is classified as a dam, in which case the facility must also comply with the Dam Safety Standards, N.J.A.C. 7:20. These design storms shall be defined as either a twenty-four hour storm using the rainfall distribution recommended by the U.S. Soil Conservation Service when using Soil Conservation Service procedures (such as U.S. Soil Conservation Service, "Urban Hydrology for Small Watersheds", Technical Release No. 55) or as the estimated maximum rainfall for the estimated time of concentration of runoff at the site when using a design method such as the Rational Method. Runoff greater than that occurring from the 100-year, twenty-four-hour storm will be passed over an emergency spillway. Detention will be provided such that after development the peak rate of flow from the site will not exceed the corresponding flow which would have been created by similar storms prior to development. For purposes of computing runoff, lands in the site shall be assumed, prior to development, to be in good condition (if the lands are pastures, lawns or parks), with good cover (if the lands are woods), or with conservation treatment (if the land is cultivated), regardless of conditions existing at the time of computation.

In calculating the site runoff to be accommodated by a detention facility, the method to be used is a tabular hydrograph method as presented in TR No. 55 (S.C.S. method) as supplemented and amended.

Detention facilities shall be located as far horizontally from surface water and as far vertically from groundwater as is practicable.

Detention facilities shall not intercept the post-development groundwater table, where practicable.

The following list of general structural criteria shall be used to design storm water detention basins. Due to the uniqueness of each storm water detention basin and the variability of soil and other site conditions, these criteria may be modified or appended at the discretion of the Municipal Engineer if reasons for the variances are indicated in writing.

To minimize the chance of clogging and to facilitate cleaning, outlet pipes shall be at least six inches in diameter. Similarly, riser pipes, if utilized, shall be at least eight inches in diameter. All pipe joints are to be watertight, reinforced concrete pipe. In addition, trash racks and/or anti-vortex devices shall be required where necessary.

Eight-inch thick anti-seep collars are to be installed along outlet pipes. Reinforcement steel shall be No. 5 bars at 12 inches both ways with two inches of cover on both faces (minimum).

Where necessary, a concrete cradle shall be provided for outlet pipes.

All principal outlet structures shall be concrete block or reinforced concrete. All construction joints are to be watertight.

Suitable lining shall be placed upstream and down-stream of principal outlets as necessary to prevent scour and erosion. Such lining shall conform to the criteria contained in Hydraulic Engineering Circular No. 15 — Design of Stable Channels with Flexible Linings published by the Federal Highway Administration of the U.S. Department of Transportation or Standards for Soil Erosion and Sediment Control in New Jersey published by the N.J. State Soil Conservation Committee.

Based upon the requirement limiting the size of the outlet to a minimum of six inches in diameter, water quality control shall be maintained by providing an amount of storage equal to the total amount of runoff which will be produced by the one-year frequency SCS Type III twenty-four-hour storm, or a 1.25 inch, two-hour rainfall at the bottom of the proposed detention basin along with a minimum three-inch diameter outlet.

The invert(s) of the principal outlet(s) used to control the larger storms for flood control purposes would then be located at the resultant water surface elevation required to produce this storage volume. Therefore, the principal outlets would only be utilized for storms in excess of 1.25 inch, two-hour event which, in turn, would be completely controlled by the lower, three-inch outlet. If the above requirements would result in a pipe smaller than three inches in diameter, the period of retention shall be waived so that three inches will be the minimum pipe size used. It should be remembered that, in all cases, the basin should be considered initially empty (i.e., the storage provided for the quality requirements and the discharge capacity of its outlet should be utilized during the routing of the larger flood control storms).

Vegetated emergency spillways shall have side slopes not exceeding three horizontal to one vertical.

Emergency spillways not excavated from noncompacted soil, shall be suitably lined and shall comply with criteria contained in Hydraulic Circular No. 15 or Standards for Soil Erosion and Sediment Control.

Maximum velocities in emergency spillways shall be checked based on the velocity of the peak flow in the spillway resulting from the routed Emergency Spillway Hydrograph. Where maximum velocities exceed those contained in Exhibit 17[12], suitable lining shall be provided.

The minimum top widths of all dams and embankments are listed below. These values have been adopted from the Standards for Soil Erosion and Sediment Control in New Jersey published by the New Jersey State Soil Conservation Committee.

The design top elevation of all dams and embankments after all settlement has taken place, shall be equal to or greater than the maximum water surface elevation in the basin resulting from the routed Freeboard Hydrograph. Therefore, the design height of the dam or embankment, defined as the vertical distance from the top down to the bottom of the deepest cut, shall be increased by the amount needed to insure that the design top elevation will be maintained following all settlement. This increase shall not be less than 5%. Where necessary, the Engineer shall require consolidation tests of the undisturbed foundation soil to more accurately determine the necessary increase.

Maximum side slopes for all dams and embankments are three horizontal to one vertical.

All earth fill shall be free from brush, roots, and other organic material subject to decomposition.

Cutoff trenches are to be excavated along the dam or embankment centerline to impervious subsoil or bedrock.

Safety ledges shall be constructed on the side slopes of all detention basins having a permanent pool of water. The ledges shall be four to six feet in width and located approximately 2 1/2 feet to three feet below and one to one and 1 1/2 feet above the permanent water surface.

The fill material in all earth dams and embankments shall be compacted to at least 95% of the maximum density obtained from compaction tests performed by the appropriate method in ASTM D698.

There will be no detention basins in the floodway except for those on-stream.

Whenever practicable, developments and their storm water detention facilities should be beyond the extent of the flood hazard area of a stream. When that is not feasible and detention facilities are proposed to be located partially or wholly within the flood hazard area (as defined by the New Jersey Division of Water Resources), or other areas which are frequently flooded, some storm conditions will make the facility in effective at providing retention of site runoff. This will happen if the stream is already overflowing its banks and the detention basin, causing the basin to be filled prior to the time it is needed. In such cases, the standards established in these regulations will be modified in order to give only partial credit to detention capabilities located within a flood hazard area. The credit will vary in a ratio intended to reflect the probability that storage in a detention basin will be available at the time a storm occurs at the site.

In addition, detention development must be in compliance with all applicable regulations under the Flood Hazard Area Control Act, N.J.S.A. 58:15A-50 et seq.

Detention storage provided below the elevation of the edge of the flood hazard area will be credited as effective storage at a reduced proportion as indicated in the table below:

As an alternative to the approach outlined in paragraph f,2 above, if the developer can demonstrate that the detention provided would be effective, during runoff from the 100-year, twenty-four-hour Type II storm, peaking simultaneously at the site and on the flood hazard area, the developer's plan will be accepted as complying with the provisions of paragraph f,2 above.

In making computations under paragraphs f,2 or f,5 above, the volume of net fill added to the flood hazard area portion of the project's site will be subtracted from the capacity of effective detention storage provided. Net fill is defined as the total amount of fill created by the project less the amount of material excavated during the construction of the project, both measured below the excavation of the 100-year flood but above the elevation of low water in the stream.

Where detention basins are proposed to be located in areas which are frequently flooded but have not been mapped as flood hazard areas, the provisions of either paragraphs f,2 or f,5 will be applied substituting the elevation of a computed 100-year flood for the elevation of the flood hazard area in paragraph f,2.

Responsibility for operation and maintenance of detention facilities, including periodic removal and disposal of accumulated particulate material and debris, shall remain with the owner or owners of the property with permanent arrangements that it shall pass to any successive owner, unless assumed by a governmental agency. If portions of the land are to be sold, legally binding arrangements shall be made to pass the basic responsibility to successors in title. These arrangements shall designate for each project the property owner, governmental agency, or other legally established entity to be permanently responsible for maintenance, hereinafter in this section referred to as the responsible person.

Prior to granting approval to any project subject to review under this Chapter, the applicant shall enter into an agreement with the municipality (or county) to ensure the continued operation and maintenance of the detention facility. This agreement shall be in a form satisfactory to the Municipal Attorney, and may include, but may not necessarily be limited to, personal guarantees, deed restrictions, covenants, and bonds. In cases where property is subdivided and sold separately, a homeowners association or similar permanent entity should be established as the responsible entity, absent an agreement by a governmental agency to assume responsibility.

In the event that the detention facility becomes a danger to public safety or public health, or if it is in need of maintenance, the municipality shall so notify in writing the responsible person. From that notice, the responsible person shall have 14 days to effect such maintenance and repair of the facility in a manner that is approved by the Municipal Engineer or his designee. If the responsible person fails or refuses to perform such maintenance and repair, the municipality may immediately proceed to do so and shall bill the cost thereof to the responsible person.

In addition to addressing water quantity generated by development, a storm water management system shall also enhance the water quality of storm water runoff.

In order to enhance the water quality of storm water runoff, storm water management shall provide for the control of a water quality design storm. The water quality design storm shall be defined as the one-year frequency SCS Type III 24 hour storm or a 1.25 inch two-hour rainfall.

The water quality design storm shall be controlled by best management practices. These include but are not limited to the following.