Patterson Dam Valve Exercise 2020 (OM-DFD-2020-016)


SCH Number
Public Agency
California Department of Water Resources (DWR)
Document Title
Patterson Dam Valve Exercise 2020 (OM-DFD-2020-016)
Document Type
NOE - Notice of Exemption
Document Description
DWR will perform routine inspection on the Patterson Dam outlet works consists of butterfly valves (BFV) on the reservoir bottom leading to a steel conduit that conveys water to the outlet structure. To avoid a sudden release of water to the drainage ditch, the 12-inch diameter steel conduit between both valves will require dewatering. The volume of water between the valves is approximately 881 gallons. The cycling of both valves and dewatering will generate about 10 gallons per minute of flow. The entire project is within the DWR right of way.

Contact Information

Todd Percival
Agency Name
Department of Water Resources
Contact Types
Lead/Public Agency

Agency Name
Division of Operations and Maintenance
Contact Types
Project Applicant


San Francisco Bay Area
Cross Streets
Patterson Pass Rd and Greenville Rd
Other Information
Patterson Dam. Mile marker: SBA MM 9.36.

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
Class 1, Existing Facilities, Section No. 15301(b)
Reasons for Exemption
The State Water Project provides significant and important services to many Californians. This project is exempt because it involves routine maintenance activities. This project will not result in impacts to special status species or habitat. Because this activity can be implemented without any significant environmental impacts, the Categorical Exemption Class 1 will be used for CEQA compliance.


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