Grading, Drainage, & Storm Water
Grading, Drainage, & Storm Water is a section within the Engineering and Construction division that reviews and issues permits related to grading, drainage and storm water for properties in unincorporated Sonoma County. Grading, Drainage, & Storm Water ensures that construction and grading do not cause flooding. Grading is the excavation (cuts) and placement (fill) of earth material by artificial means. Storm water is any storm water runoff, snow melt, or surface runoff.
Sonoma Water’s Board of Directors adopted a resolution approving the Flood Management Design Manual (FMDM) to provide guidance and criteria for the conveyance of storm water. The FMDM is a significant update to the existing criteria and will replace the current Sonoma County Water Agency Flood Control Design Criteria (FCDC).