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 , or any subdivision creating public or private roadways, 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 property and infrastructure from being damaged during the storm event. At the time of application, the applicant shall designate a person or organization that shall be responsible for continuous maintenance of the storm water system. The storm water system shall be maintained at all times to operate at its original design capacities. Authorized representatives of Vernal City may enter upon any site to conduct inspections and verify compliance with Vernal City Code. The maximum slope in any part of an above ground retention device or basin shall be 3:1. All water must dissipate from all above ground storage device or basins within seventy-two (72) hours. Above ground retention devices and basins shall be landscaped in accordance with Section 16.27. The lowest grade in all retention basin devices and basins, above or below ground, shall be a minimum of two (2) feet above the existing water table. Surface drainage is not allowed across pedestrian walkways. Storm drainage facilities shall be installed in accordance with Vernal City standards and all applicable State of Utah and federal standards and requirements. (PZSC § 03-02-005.1)(Ord. No. 95-20, Amended, 11/02/95; Ord. No. 96-07, Amended, 03/20/96)

(Ord. 2009-09, Amended, 08/19/2009, Prior Text; Ord. 2007-05, Amended, 04/25/2007, Prior Text)