Laserfiche WebLink
Section 32-273. <br /> <br />Parking lots; internal drainage <br />requirements. <br /> <br /> (a) Internal drainage shall be required for parking lots <br />where the city engineer considers sufficient room to exist for <br />ten (10) or more parked cars in standard configuration and <br />where, in the opinion of the city engineer, the combination of <br />rooftop area and parking lot area will cause sufficient storm <br />water runoff to warrant the requirement. Internal drainage <br />requirements shall be calculated based upon all storm water <br />runoff within the property to be developed, and shall include <br />rooftops and parking areas. Only the concrete apron between <br />the property line and the curb shall be allowed to drain to <br />the street. Catch basins for the internal drainage shall be <br />provided in all parking areas outside of the street <br />right-of-way, and storm drainage pipes shall extend to the <br />nearest drainage facility of sufficient capacity. The above <br />requirements shall be mandatory except: <br /> <br />(i) <br /> <br />Where underground drainage pipe culverts are not <br />available within one hundred fifty (150) feet of the <br />parking lot, and when the developer receives the <br />concurrence of the city engineer, with the certified <br />statement and calculations of the developer's <br />registered professional engineer or a licensed (3B) <br />land surveyor, that no hazard or danger would result <br />from the restricted release of storm waters into the <br />city street or right-of-way while: <br /> <br />a) <br /> <br />Using, in the calculations, a storm water <br />runoff coefficient for a parking lot paved in <br />its entirety with nonporous bituminous <br />concrete; and <br /> <br />Detaining all storm waters up to a minimum <br />storm of five-year frequency with a controlled <br />release into the city right-of-way of only <br />those quantities that would result from a storm <br />of a two-year frequency with the site in its <br />undeveloped state. <br /> <br />Criteria for finding that a hazardous condition <br />exists may include, but are not limited to, the <br />exceeding of an eight-foot spread of storm water <br />a curbed street for a two-year storm frequency at <br />the nearest downstream inlet. <br /> <br />in <br /> <br />(2) <br /> <br />Where alterations are proposed to a building with <br />existing parking lot with inadequate internal <br />drainage, the facility may continue to be used <br />without installation of internal drainage if: <br /> <br />an <br /> <br /> <br />