Chapter 914-12 — DETENTION BASINS

Detention basins may be utilized only if they are approved by the public works department and contain at least fifteen acre-feet of storage capacity to provide regional flow mitigation benefits, except that smaller detention basins may be permitted where it can be shown to the satisfaction of the public works department that the development of a regional basin is not practical and that a smaller detention basin can be permanently operated and maintained by a public entity in a cost-effective manner.

(Ords. 89-28, 78-5).

Detention basins shall be sized to provide the desired reduction in peak channel flows and to store with freeboard the design average recurrence interval runoff. Detention basins shall also be sized to contain without freeboard a one-hundred-year average recurrence interval runoff, unless it can be shown that a one- hundred-year average recurrence interval runoff can be safely passed through the detention basin without damage to the detention basin or any other property.

(Ord. 89-28).

(a)

The design of a detention basin shall comply with the requirements of the state of California, Division of Dam Safety.

(b)

Detention basin side slopes shall be determined by a licensed soil engineer and presented in a soil report and in no case shall the side slopes of non-natural slopes be steeper than four horizontal to one vertical.

(c)

Detention basins and their appurtenant facilities shall conform with current design standards of the public works department.

(Ord. 89-28).

A detention basin facility shall be used for no purpose other than drainage or flood control without the written approval of the public works department and the execution of a joint use agreement in a form approved by the county counsel.

(Ord. 89-28).

The subdivider shall insure the maintenance of a detention basin facility through either an existing public maintenance entity or by the creation of a public maintenance entity. The entity shall have an adequate revenue source to assure perpetual maintenance.

(Ord. 89-28).

Infiltration basins shall not be permitted.

(Ord. 89-28).