Agenda - 01-06-1986 - Laserfiche WebLink

Browse Search

1'• 121 a flow of 3.4 cfs. This stormwater will travel approximately 4S0FT across natural vegetation before it discharges into a small stream. Th',e low runoff amount combined with the travel distance will allow pollutants to settle out. Any runoff from the individual sites will be infiltrating and filtering through a minimum of 40,000+/- square feet of natural ,vegetation from each site prior to being discharged into the ponds or across any portion of the remaining 45+/- acres to retain undisturbed.' This should be an adequate amount of natural vegetation for the pollutants to filter through. 1 The ponds also provide an important roll in slowing down and - retaining the runoff from this site. The ponds retain the first portion of stormwater. The first portion of the runoff contains the greatest amount of pollutants therefore this would be the most • critical toi contain. By the ponds retaining this runoff, the stormwater has time to slow down and allow pollutants to settle. The two (2) existing ponds are acting as a natural detention for the upper portion of the site. A third pond will be added to . retain any runoff from the lower portion of the. site and to refilter stormwater from the upper two (2) ponds. The ponds (will act as a secondary filtering system to any pollutants contained in the runoff after it has passed through the grassed swales or has not infiltrated into the surface. Therefore, it can be concluded that the site with its rolling terrain and natural watershed feeding the ponds, combined with the 1 low density and impervious material, provides an ideal combination to infiltrate and detain runoff. The low ratio of impervious material to the vegetation of 4.7% is acceptable and should allow sufficient infiltration and settlement of pollutants to occur. 1 1 i 1 1 1' il i. Mindy Hill Fara 12/12/85 Page 3 1