County ordinances require that proposed work in creeks in unincorporated areas be reviews and allowed only by a County Drainage Permit. The Contra Costa County Flood Control and Water Conservation District (FC District) boundaries cover all of Contra Costa County. Within FC District right of ways (where FC District faculties were built and are maintained) a FC District Encroachment Permit is required. Within it's right of way FC District can dictate construction standards and methods, hydraulic and hydrology calculation methods, and other standards such as freeboard standards. The County has adopted the FC District standards and so in the unincorporated areas the FC District standards are used. FEMA will require you to use the FCD flow rates in any FEMA study. Other State and Federal entities have authority to control work with in creeks and riparian areas. When you apply for a Drainage Permit or FC District Encroachment Permit, we ensure that the permits are obtained from those entities as well.