Section 16.06.060 Provision for storm drainage--Retention on own property.

All commercial, institutional or industrial development, construction, reconstruction, alteration, or expansion which generates any storm drainage proposing a site plan or any multiple-family housing development containing (5) or more units shall be required to convey and retain all storm water drainage on its own property at a design rainfall volume and peak discharge in accordance with a twenty-four (24) hour storm duration with a one hundred (100) year return period. Calculations shall be based on standard engineering methods, or if computer modeling is used, Natural Resource Conservation Service (Soil Conservation Service) methods Tr-20 or Tr-55 using a type II rainfall distribution curve. Rainfall depths used shall be in accordance with National Atmospheric & Oceanic Administration estimates for the Vernal Airport. Conveyance shall be designed and constructed in such a fashion as to prevent private proeprty and infrastructure from being damaged during the storm event. (PZSC § 03-02-005.1)(Ord. No. 95-20, Amended, 11/02/95; Ord. No. 96-07, Amended, 03/20/96)