Chapter 192: Stormwater Runoff in New Developments

Section

   192-01   Definitions

   192-02   Purpose; exception

   192-03   Retention methods

   192-04   Retention basin standards

   192-05   On-site retention standards; residential, commercial and industrial

   192-06   Combination storage

   192-07   Minimum floor elevation

   192-08   Surface alteration

   192-09   Estimated return periods for short-duration precipitation

§ 192-01 Definitions.

   For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.

   BUILDING FLOOR ELEVATION. The finished floor elevation in feet above mean sea level of the lowest floor of a building. BUILDING FLOOR ELEVATIONS shall be related to the city datum.

   BUILDING PAD ELEVATION. The elevation in feet above mean sea level of the material on which the floor slab directly rests.

   COMBINATION STORAGE. Handling of stormwater by utilizing both on-site retention and retention basins.

   DRAINAGE PLAN. That certain plan on which are shown the location, dimensions and elevations of proposed stormwater storage areas.

   FIFTY-YEAR STORM. A storm that has a two percent chance of occurring each year in accordance with criteria established by the U.S. National Weather Service, as shown in § 192-09.

   FREE BOARD. The distance between the design high water surface and the top of the wall of a retention basin.

   100-YEAR STORM. A storm that has a one percent chance of occurring each year in accordance with criteria established by the U.S. National Weather Service, as shown in § 192-09.

   ON-SITE RETENTION. Storage on public or private property or any combination thereof, but not on public street or alley right-of-way.

   RETENTION BASIN. A designated area for total storage, without overland relief, of flows generated during a design storm.

   10-YEAR STORM. A storm that has a ten percent chance of occurring each year in accordance with criteria established by the U.S. National Weather Service, as shown in § 192-09.

('80 Code, § 31-143) (Ord. 1670, passed 10-12-77)

§ 192-02 Purpose; Exception.

   (A)   The purpose of this chapter is to require the owner/developer of each lot, plot or parcel of land within the city limits to provide storage of sufficient volume to hold the total runoff from the design storm falling on that lot, plot or parcel of land. An exception to this requirement will be granted by the City Engineer only when runoff can be directed into a storm sewer, channel or natural drainageway with sufficient capacity to transport storm water to an approved ultimate disposal site. The owner/developer shall not be required to provide storage for runoff from land other than his own except where it can be proven that flow from adjacent land has historically crossed or inundated the land of the owner/developer.

   (B)   This chapter and its revision(s) are intended to be as closely compatible with the long range goals of the Yuma County Flood Control District.

('80 Code, § 31-144) (Ord. 1670, passed 10-12-77; Ord. 1836, passed 6- 20-79; Ord. O2021-021, passed 8-4-2021)

§ 192-03 Retention Methods.

   Storm water shall be contained within each lot, plot or parcel of land by any of the following methods:

   (A)   On-site retention.

   (B)   Retention basin.

   (C)   Combination storage.

('80 Code, § 31-146) (Ord. 1670, passed 10-12-77)