§ 192-05  On-Site Retention Standards; Residential, Commercial and Industrial.
   (A)   Residential.  When on-site retention is utilized in residential subdivisions, the following design criteria shall be applicable:
      (1)   Minimum lot size for on-site retention shall be 8,000 square feet.  A deed covenant prohibiting alteration of the final site ground elevations shall be required.  The minimum design depth of storm water storage on any lot shall not exceed eight inches except as approved by the City Engineer.
      (2)   The lot depth below the back edge of the sidewalk shall be computed using a 100-year storm of 24-hour duration with 3.85 inches of total rainfall.  An allowance for evaporation and/or percolation shall not be incorporated into the computations for minimum lot depth.  Storage volume shall also be provided for adjacent streets and alleys except for arterial streets.
      (3)   Each lot shall be provided with an earthen berm around the back and sides of each lot.  The earthen berm shall be one foot higher than the adjacent final ground elevation of the lot.
      (4)   All residential streets shall have vertical curb and gutter designed in accordance with accepted city construction standards.  An appropriate means of transporting water into the storage area shall be provided.
      (5)   Slope away from building shall not exceed 20:1 for a distance of five feet out from the foundation.
('80 Code, § 31-148)
   (B)   Commercial, industrial.  When on-site retention is utilized in commercial and industrial developments, all storm water from a 100-year storm of one hour duration (2.25 inches) must be retained on-site.  Dry wells will be permitted to drain surface retention areas.  However, the infiltration cannot be considered to reduce the volume of the retention area.  The City of Yuma shall not be responsible for the design, performance, operation or maintenance of dry wells or retention basins in commercial or industrial developments.  Dry wells shall not be located within 20 feet of any building(s). ('80 Code, § 31-149)
(Ord. 1670, passed 10-12-77; Ord. 1836, passed 6-20-79; Ord. O2021-021, passed 8-4-2021)  Penalty, see § 193-99