1 - Water Course Disruption Permit Purpose & Definition

Revised on 04-13-2022


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A Water Course Disruption Permit is a required Public Works permit for construction work on private property within a water course as defined below.  Any person desiring to construct, reconstruct, repair any natural water course, or build any structure within any natural water course must obtain a Water Course Disruption Permit from the Board of Public Works. The Board of Public Works has delegated said responsibility to BOE.

No person shall do anything to any natural water course or any channel that may carry storm water that would in any manner obstruct or interfere with the flow of water through such course or channel without first obtaining a permit from BOE.

Many wetland or stream projects will require permits or approvals from other agencies.  The key to a project’s timely completion will be the Applicant's understanding of these requirements.


Water Course

Magnifying glass graphicA water course is any natural or man-made depression with a bed and with or without well-defined banks below the surrounding land serving to give direction to a current of water, or pattern of runoff from a drainage area of any size.

Any alterations to a natural water course that modify its course or flow, such as diverting the flow into a new conduit, does not affect its status as a natural water course. The water course is used by water passing down as a collected body or stream in those seasons of the year and at those times when the streams in the region are accustomed to flow. A natural water course includes all channels through which, in the existing condition of the flow, the water naturally flows and may include new channels created in the course of urban development through which waters presently flow. Water course also includes any arroyo, canal, channel, conduit, creek, culvert, ditch, drain, gully, ravine, reservoir, stream, wash, waterway or wetland.  

Additional information about the types of permits an Applicant should apply for based on the scope of work, can be found under "Other BOE Permits/Processes, Technical Procedures, 06-Permit Classification Matrix". 

Special Flood Risk Areas

The definition of Special Flood Risk Areas and the applicable special requirements for Watercourse Permits can be found in Special Order No. 003-1005. The only currently designated Special Flood Risk Area is Mandeville Canyon. Other areas will be added as they are identified.

Waters of the United States (per the US Army Corps of Engineers)

Any stream shown as a solid or broken blue line on 7.5 Minute Series quadrangle maps prepared by the U.S. Department of the Interior Geological Survey (USGS). A blue line stream may be any creek, stream or other flowing water feature, perennial or ephemeral, indicated on USGS quadrangle maps, with the exception of man-made water courses. The United States Army Corps of Engineers uses USGS blue line stream markings as a preliminary indicator of “Waters of the United States”. Streams identified on USGS maps in such a manner are therefore generally subject to federal environmental regulations. 


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