Victorville Municipal Code Art. 7 Drainage

Calculation of design flood flows shall be based on the frequency of occurrence hereinafter stipulated in this Title using the rational method of analysis and assuming full development of all the property within the drainage area based upon the General Plan of the City for future development and Development Code and the General Plan and Zoning Code of the County where applicable. Any outlet channel required to carry the stormwater from the proposed subdivision to a defined drainage channel or conduit shall be designed in accordance with the standards set forth in this Chapter, for the ultimate stage of development of the subdivision and any additional tributary areas and the one hundred-year frequency of occurrence flood.

Drainage channels and conduits shall have the following minimum capacities:

(a) Primary drainage channels and conduits shall have sufficient capacity to contain the one hundred-year frequency of occurrence runoff and be designed in accordance with the Standard Specifications for Public Improvements.

(b) Minor drainage channels or conduits shall have sufficient capacity to contain a ten-year frequency of occurrence runoff when designed in accordance with the Standard Specifications for Public Improvements.

Proposed subdivisions shall not cause inundation or flood hazard to existing inhabited areas or downstream properties. Measures shall be taken in design to minimize sedimentation and concentration of flood flows on downstream properties.

Drainage shall be accomplished by gravity surcharge into catch basins or manholes, except by design in accordance with standards set forth in this Chapter and the Standard Specifications for Public Improvements of the City.

Catchbasins shall have inlets of varying length so designed that the water is diverted into the catchbasin without bypassing. Catchbasin inlets shall be designed in accordance with the Standard Specifications for Public Improvements.

(a) Cross-gutters shall be used to carry water across streets at intersections only. Where a street must cross a major wash, the standard wash crossing as set forth in the Standard Specifications for Public Improvements shall be utilized. The street shall be designed to pass the full flood flow of the wash without damage to the street or the adjacent properties.

(b) Where it is necessary to carry local drainage across the street in the middle of the block, it shall be carried in pipe designed in accordance with the Standard Specifications for Public Improvements.