Final IS/MND: Water Reliability Transmission and Distribution Improvement - Conn Creek Water Line Project

3 Documents in Project


SCH Number
Lead Agency
City of Calistoga
Document Title
Final IS/MND: Water Reliability Transmission and Distribution Improvement - Conn Creek Water Line Project
Document Type
FIN - Final Document
Document Description
The Final IS/MND has been updated to include a response to comments section in Appendix G. Two comment letters were received during the public review and comment period. Copies of these comments and the City's responses are included in Appendix G. Text clarifications and modifications made in response to the comments received are identified in Appendix G and reflected in the Final IS/MND. No new or more significant impacts were identified during the public review period. No new mitigation measures are included in the Final IS/MND. The project would upgrade an underground segment of the existing North Bay Aqueduct (NBA) pipeline that crosses the Conn Creek floodway. Approximately 100 linear feet of the underground NBA pipeline alignment is proposed to be relocated to an elevated position on the new Conn Creek Bridge, which was replaced by the California Department of Transportation (Caltrans) in 2020. In addition, the project includes replacement of up to 3,000 linear feet of 12-inch-diameter underground pipeline with new 16-inch-diameter underground pipeline in the same location parallel to and along the south side of Silverado Trail, which is a two-lane public roadway and a portion of which is also Highway 128. The project is one of three projects identified in the City’s grant application for Water Reliability Transmission Distribution Improvement projects. Grant funding was awarded in 2018 under the Federal Emergency Management Agency (FEMA) Hazard Mitigation Grant Program (HMGP).

Contact Information

Hamid Heidary
Agency Name
City of Calistoga
Contact Types
Lead/Public Agency


Cross Streets
Conn Creek Road and Silverado Trail/Highway 128

Notice of Completion

State Reviewing Agencies
California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Transportation, District 4 (DOT), California Department of Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), Department of Toxic Substances Control, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Divison of Financial Assistance
Development Types
Water Facilities (Replacement)(Type pipeline , MGD 1)
Local Actions
Encroachment Permit
Project Issues
Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Drainage/Absorption, Energy, Flood Plain/Flooding, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Wetland/Riparian, Wildfire


Final Document(s) [Approved_Certified draft environmental documents]

Disclaimer: The Governor’s Office of Planning and Research (OPR) accepts no responsibility for the content or accessibility of these documents. To obtain an attachment in a different format, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at or via phone at (916) 445-0613. For more information, please visit OPR’s Accessibility Site.

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