222 W CASINO RD 2018-01-01 MF Import

. . . ._.:, ., _ ..., . _., , _ _,..:, .,,... , ,., ..,..-.�..,. .., . _,.. ._ ..,. .,. .. .., . _ i ., - DESIGN CRITERIA FOR GRASSED SWALES 1. Grassed swales shall be designed for a maximum velocity of four feet per I second and a maximum flow depth of six inches during a ten year storm. �, For severe site restrictions, a bypass piping system may be allowed to achieve the max:mum veloclty and depth criteria. , � � 2. Th2 side slopes of the grassed swale shall be 3:1 or less. , 3, Check dams shall be provided across the qrassed swales at 100 foot intervals to increase soil infiltration. The check dams shall be rock, railroad tie or other appropriate material. 4. The longitudinal slope of grassed swales shall be minimized to increase soil infiltration and in no case shall exceed 5%. 5. The underlying soils shall be tilled before grass cover is provided to restore the soil's infiltration capacity. 6. Grass cover shall be provided by hydroseeding fran April 1 through October 1. During the rest of the year, sod will be required ur a comparable water quality control method. 7, Grassed swales shall generally be required for all sites with an asphalt prved area of 10,000 square feet or greater. Grassed swales may be required for paved areas less than 10,000 square feet for land uses with a comparatively high risk for polluted stormwater runoff, such as, gas stations and automotive parts stores. ' 9. The minimum length of any grassed swale shall be 100 feet. 9. The required total length of grassed swale can be determined as follows: Total Site Paved Area Total Length of Grassed Swale 10,000 sq. ft. 100 linear ft. 10,000 sq. ft. to 50,000 sq. ft. Add 10 linear ft. for every additional G,000 sq. Pt. of paved area Greater than 50,000 sq. ft. Add 5 linear ft. for 2very additional 4,000 sq. ft. of paved area 4386H � i