(A) All storm water control devices shall be designed by a professional registered with the state who has the necessary qualifications appropriate for the type of device which is to be designed and/or constructed.
(B) Wherever possible, development should be punned and constructed in such a way as to maintain the natural drainage of the property on which the development is occurring.
(C) Where development is of a high density nature, such as in the case of apartments, mobile home parks, planned unit developments (PUDs), shopping centers (retail or wholesale outlet stores included), shopping malls, schools, industrial parks or large industrial plants or, in cases where the total impervious area to be constructed exceeds 30% of the total square area of the entire parcel of property, detention ponds shall be the primary device used to control storm water runoff. In cases where insufficient land is available to construct a detention pond or other significant spatial or physical constraints exist, sand filters, bioretention areas or other innovative types of storm water control devices may be considered for approval by the town on a case-by-case basis.
(D) Detention ponds shall be constructed so as hold an amount of water equivalent to a ten-year frequency storm. All detention ponds, whether wet or dry, shall be enclosed by a vegetative buffer of no less than ten feet in width. Additionally, in cases where a dry detention pond is used for storm water control, the pond must be enclosed by vegetation or fencing of no less than six feet in height and of a thickness as to screen the pond from view and prohibit unintended access to the pond.
(E) The first one inch of runoff from all impervious surfaces shall be detained from reaching any watercourses through the use of vegetated areas specifically designed and maintained for infiltration purposes. Vegetative filters may be constructed of natural vegetation, grasses or artificially planted wetland vegetation appropriate for the site characteristics. The slope, width and length of the vegetative filters shall be calculated so as to provide a non-erosive velocity of flow through the filter equivalent to a ten-year, 24-hour storm.
(F) The slopes of detention ponds, swales, vegetative filters and other similar storm water management devices shall be determined by BMP, but in no case shall they be steeper than three to one (horizontal to vertical). Where this is not practical due to physical constraints, check dams or other types of devices may be required to slow the rate of runoff and encourage infiltration. Slopes of storm water control devices shall be stabilized with vegetative cover wherever possible.
(G) Stockpiles of materials having exposure to rain which could pose potential pollution or health risks shall be kept covered or else stored in such a manner as to minimize the risks. Protection measures may include using flexible waterproof coverings or placing the materials under some form of permanent or semi-permanent shelter.
(H) Upon completion of construction of a storm water control device or facility, certification shall be provided by an authorized registered professional that the materials and workmanship employed in the construction of the device or facility meets or exceeds all requirements and standards set forth in this subchapter or those of any other state or local ordinances which may be apply.
(Prior Code, § 52.06) (Ord. passed - -1997)