Environmental Documents

Below are recent Environmental Impact Reports, Notice of Availabilities, and Notices of Preparation of an Initial Study for Sonoma Water Projects. Learn more about regulatory compliance.

Looking for the Public Notices webpage? Click here.

Notice of Exemption Mark West Wikiup Open Space Preserve Fee Title Purchase and Conservation Easement

Date Posted: 12/12/2023

Project Location: Unincorporated Sonoma County

Project Description: Sonoma County Agricultural Preservation and Open Space District (District) is funding Sonoma County Water Agency’s (Sonoma Water) purchase of a fee interest of the approximately 30-acre property. Sonoma Water is acquiring the property for the potential to further programs related to habitat restoration, groundwater opportunities, water education, and recreational opportunities for the public. Sonoma Water will execute a Purchase and Sale Agreement with the landowner WBR, LLC. As a condition of the District’s funding, Sonoma Water will convey a conservation easement and recreation conservation covenant, along with an associated Offer to Dedicate the fee interest, to the District at closing. The conservation easement will protect the scenic, natural, recreational, and educational resource values of the Property, which is adjacent Mark West Creek and the densely populated Larkfield-Wikiup neighborhood. The recreation covenant will ensure the Property is open to the public within three years after execution and in perpetuity as a park and open space preserve after future compliance with the California Environmental Quality Act (CEQA).

View Notice of Exemption


Notice Of Availability / Notice Of Intent To Adopt Initial Study And Mitigated Negative Declaration For The Sonoma Valley County Sanitation District System Protection Plan At Kohler & Sonoma Creek Crossings Project 

Date Posted: July 17, 2023 

Public Review Period: July 18 to August 16, 2023 

The Sonoma Valley County Sanitation District (District) is the Lead Agency in accordance with the California Environmental Quality Act (CEQA) for the proposed Sonoma Valley County Sanitation District System Protection Plan at Kohler & Sonoma Creek Crossings Project (Proposed Project). The Proposed Project is a sanitary sewer protection and streambank stabilization project. Sonoma County Water Agency (Sonoma Water) manages the District. The District has prepared a Draft Initial Study and Mitigated Negative Declaration (IS/MND) for the Proposed Project in accordance with the California Environmental Quality Act (CEQA), the State CEQA Guidelines, and Sonoma Water’s Procedures for Implementation of CEQA. This notice is to announce that the IS/MND is available for review by the public, agencies, and interested parties. Instructions for submitting comments on the document are included in this notice. 

Project Location: The Proposed Project site is located primarily on residential private property at 13965 Arnold Drive, south of the town of Glen Ellen at the confluence of Sonoma Creek and Kohler Creek. Construction work would occur within and along the banks of Kohler and Sonoma creeks. Temporary construction, maintenance, and monitoring easements and new perpetual sewer easements would be required on private parcels surrounding the construction area. 

Project Description: The Sonoma Valley County Sanitation District System Protection Plan at Kohler & Sonoma Creek Crossings Project would implement permanent repairs along Kohler and Sonoma creeks and establish new and expanded easements to provide access along the pipeline routes for repair and maintenance purposes.


Notice of Availability / Notice of Intent to Adopt Initial Study and Mitigated Negative Declaration for the Russian River County Sanitation District Headworks, Lift Stations, And Force Mains Project

Date Posted: June 30, 2023

Public Review Period: July 1, 2023 to July 31, 2023

The Sonoma County Water Agency (Sonoma Water) is the Lead Agency under the California Environmental Quality Act (CEQA) for the proposed Russian River County Sanitation District Headworks, Lift Stations, and Force Mains Project (Proposed Project). Sonoma Water has prepared an Initial Study and Mitigated Negative Declaration (IS/MND) for the project in accordance with the California Environmental Quality Act (CEQA), the State CEQA Guidelines, and Sonoma Water’s Procedures for Implementation of CEQA. This notice is to announce that the IS/MND is available for review by the public, agencies, and interested parties. Instructions for submitting comments on the document are included in this notice.

Project Location: The Russian River County Sanitation District serves and the Proposed Project is located in the unincorporated areas of Rio Nido, Guerneville, Guernewood Park, and Vacation Beach in west Sonoma County. 

Project Description: The Proposed Project would reduce the potential for sanitary sewer overflows and leaking pipes, and reduce the risk of the loss of sanitation service resulting from failures of deteriorating infrastructure due to ground deformation, liquefaction, or lateral ground movement caused by a moderate or severe earthquake. To maintain safe and reliable sanitation service during a seismic event, the Proposed Project would also improve the ability of the Main Force Main to withstand the effects of ground deformation, liquefaction, and lateral spread hazards at the Russian River crossing. The Proposed Project would include repairing and replacing existing components of the headworks at the wastewater treatment plant, as well as repairing and replacing existing components at the 11 lift stations located within the RRCSD. Proposed repairs at the lift stations include replacing existing lift station platforms, installing new flow meter vaults, and regrading.

The Proposed Project would replace segments of the existing force main pipeline on the Beanwood, Rio Nido, and Main force main alignments. The Proposed Project would replace a segment of the Beanwood Force Main that is attached underneath the Guerneville Bridge. The Proposed Project would also replace a segment of the existing Main Force Main that crosses under the Russian River near the Vacation Beach summer crossing. The new Main Force Main pipeline segment would be microtunneled approximately 30 feet to 45 feet below the riverbed to replace the existing pipeline segment. The existing pipeline segment would be disconnected, filled with a low strength concrete mixture, and abandoned in place. Work on the force mains would improve their ability to withstand the effects of ground deformation, liquefaction, and lateral spread hazards. 


Notice of Availability / Notice of Intent to Adopt Initial Study and Mitigated Negative Declaration for the Santa Rosa Creek Fish Passage Improvements Project

Date Posted: June 28, 2023

Public Review Period: June 29, 2023, to July 28, 2023

The Sonoma County Water Agency (Sonoma Water) is the Lead Agency under the California Environmental Quality Act (CEQA) for the proposed Santa Rosa Creek Fish Passage Improvements Project (Proposed Project). Sonoma Water has prepared an Initial Study and Mitigated Negative Declaration (IS/MND) for the project in accordance with the CEQA, the State CEQA Guidelines, and Sonoma Water’s Procedures for Implementation of CEQA. This notice is to announce that the IS/MND is available for review by the public, agencies, and interested parties. Instructions for submitting comments on the document are included in this notice.

Project Location: The Proposed Project site is located on Santa Rosa Creek at two locations in the City of Santa Rosa:

  • The E Street Bridge Fishway Extension site is located at the intersection of E Street between Sonoma Avenue and Second Street within a developed commercial and residential area. 
  • The Melita Road Dam site is adjacent to Montgomery Drive at Melita Road. 

Project Description: There are barriers to fish passage along Santa Rosa Creek at the E Street Bridge Fishway Extension and Melita Road Dam sites due to non-functioning structures and erosion. Additionally, site conditions limit regular maintenance at the E Street Bridge Fishway Extension. The purpose of the Proposed Project is to improve fish passage, primarily for steelhead, over a broader range of flows at the E Street Bridge Fishway Extension and Melita Road Dam sites, address ongoing erosion to the right bank at the E Street Bridge Fishway Extension site, and improve access for and reduce the frequency and extent of channel maintenance needs to maintain fish passage through the E Street Bridge Fishway Extension site.

Proposed Project construction activities would include replacing and structurally improving the fishway extension, removing the existing trash rack and installing a system of improved trash racks installing grouted rock upstream of the fishway extension to support the grouted rock weirs and fishway extension infrastructure, enhancing the right bank to address erosion, and constructing an access road for maintenance activities at the E Street Bridge Fishway Extension site. At the Melita Road Dam site, a series of non-grouted rock weir step pools would be installed below the dam site to facilitate fish passage.


Cotati No.1 and Kastania Water Storage Tank Recoating Project

Date Posted: 4/4/2023

Project Location: Cotati and Petaluma 

Project Description: The project consists of actions to meet current health and safety standards for ongoing operations and maintenance activities of existing water storage facilities. The purpose of the propject is to maintain the service life of the existing potable water storage tanks and maintain existing water quality-related appurtenances designed to protect public drinking water sources from contamination. 

View Notice Of Exemption


Notice Of Availability / Notice Of Intent To Adopt Initial Study And Mitigated Negative Declaration For The Laguna-mark West Creek Watershed Master Restoration Planning Project – High Priority Project

Date Posted: 2/22/2023

Public Review Period: February 23, 2023, to March 27, 2023 

Project Location: The Proposed Project site encompasses approximately 119.43 acres along a 3,200-foot-long reach of the Laguna de Santa Rosa (Laguna) between the confluences of Santa Rosa and Mark West creeks, approximately five miles west of the City of Santa Rosa, in Sonoma County, California

Project Description: The Proposed Project would restore a 3,200-foot-long reach of the Laguna and freshwater marsh, wet meadow, and riparian forest habitats on 119.43 acres along the Laguna. The Proposed Project site historically supported these habitat types prior to agricultural development. By realigning the Laguna channel to its historical path, the Proposed Project site would inundate more gradually during floods and drain slowly as floodwaters recede than under current conditions. 


CEQA Exemptions under Governor’s Executive Order N-7-22

On March 28, 2022, the Governor issued Executive Order N-7-22 to bolster regional water conservation efforts. The Executive Order suspends Public Resources Code, Division 13 (commencing with section 21000, also known as the California Environmental Quality Act or CEQA) and regulations adopted pursuant to that Division under specified circumstances. Section 12 of EO N-7-22 suspends CEQA to advance groundwater recharge projects and to demonstrate feasibility of projects that can use available high water flows to recharge local groundwater while minimizing flood risk and applies to (a) any actions taken by state agencies, (b) any actions taken by local agencies where the state agency with primary responsibility for the implementation of the directives concurs that local action is required, and (c) permits necessary to carry out actions under (a) or (b). The entities implementing these directives shall maintain on their websites a list of all activities or approvals for which these provisions are suspended. 

Sonoma Water, as the local lead agency, has determined that a suspension of CEQA is appropriate under Executive Order N-7-22 for the following projects:


Petitions Requesting Approval of Temporary Urgency Changes in Water Right Permits 12947A, 12949, 12950, and 16596 in Mendocino and Sonoma Counties

Date Posted: 10/27/2022

Project Location - County: Mendocino and Sonoma 

Description: The Sonoma County Water Agency (Sonoma Water) seeks temporary urgency changes to its four water-right permits used to provide wholesale water to cities and water districts in Sonoma and Marin counties. These changes are necessary to ensure that minimum instream flow requirements in the Russian River watershed are aligned with actual watershed hydrologic conditions. This is essential to maintain sustainable reservoir /river operations to protect municipal water supply and listed salmonid species in the Russian River. 

View: Notice of Exemption 


Hudeman Slough Enhancement Wetlands: Maintenance Project 2022

Date Posted: 10/4/2022

Project Location: The project is located in unincorporated Sonoma County, approximately 6 miles southeast of the town of Sonoma.

Description: The purpose of the proposed project is to maintain existing levee roads and access roads at the Hudeman Slough Enhancement Wetlands. These enhancement wetlands put reclaimed water to beneffcial use by maintaining freshwater wetlands for wildlife habitat and the roads provide public access. The proposed project consists of road maintenance along approximately 3 miles of existing levees and other gravel roads by adding gravel to the surface and installing pipe culverts at two small drainages that cross the main access road. These tasks would be completed in and maintained for five years.

View Notice of Exemption


Joint Acquisition of Demuth Property with Sonoma County Regional Parks Department Notice of Exemption

The project consists of the joint acquisition of the Demuth property with Sonoma County Parks Department (Regional Parks). The property is adjacent to the historic Wohler Bridge and lands owned by the Sonoma County Water Agency (Sonoma Water). The purpose of the acquisition for Regional Parks is for park purposes and the purpose of acquisition for Sonoma Water has not been identified. There is a potential to use a portion of the property for a facility for Sonoma Water, but that portion of the project is not defined in sufficient detail. Further development of the property would be subject to future environmental review pursuant to California Environmental Quality Act.

If you have any questions regarding this NOE, please contact Yvette O’Keefe at (707) 547-1943 or email yvette.o'keefe@scwa.ca.gov.

View Notice of Exemption


Temporary Urgency Change Petition Notice of Exemption

Date Posted: 5/26/2022 

The Sonoma County Water Agency (Sonoma Water) seeks temporary urgency changes to its four water-right permits used to provide wholesale water to cities and water districts in Sonoma and Marin counties. 

These changes are necessary to ensure that minimum instream flow requirements in the Russian River watershed are aligned with actual watershed hydrologic conditions. This is essential to maintain sustainable reservoir /river operations to protect municipal water supply and listed salmonid species in the Russian River.

View May 2022 Temporary Urgency Change Petition 


Reinforcement of Temporary Slope Stabilization and Sanitary Sewer Protection 

Date Posted: 5/17/2022

Project Location: Town of Glen Ellen

Description: The Proposed Project would secure an existing emergency and temporary bank stabilization project completed in 2019. A concrete K-rail and rock riprap were installed on a steep eroding bank along Sonoma Creek to prevent the rupture of a sewer pipeline that crosses beneath the creek. The Proposed Project would secure the K-rail by installing three verlical support pins, filling voids beneath the K-rail with rock or gravel-filled bags, and placing boards to cover the filled voids.  No aquatic or riparian habitats, including trees would be disturbed. 


Emergency Sebastopol Road Well Activation Project

Date Posted: 3/10/2022

Project Location: Project Location -Specific: 5590 Sebastopol Road (Highway 12), 0.4 mile west of Llano Road, Sonoma County, California

Description: The purpose of the project is to provide supplemental water from the existing well to support agriculture and public water retailers (cities and water districts) during the drought emergency. The project will consist of installing additional piping and associated equipment from the well to the underground pipeline to ensure chlorine contact time regulatory requirements are met for potable water use.

View Notice of Exemption 


Lake Sonoma Quagga and Zebra Mussel Inspection Project

Date Posted: 2/17/2022

Description: Quagga and zebra mussels are invasive mussel species that, if introduced into a waterway, can devastate the natural environment, clog water and flood protection infrastructure, and cost millions of dollars in maintenance. These mussels are transported between waterways by watercraft, primarily recreational boats. The proposed project would provide watercraft inspection services to prevent quagga and zebra mussel infestation into Lake Sonoma. The proposed project would also provide inspection training to help develop year-round inspections. 

View Notice of Exemption

If you have any questions regarding this NOE, please contact Connie Barton at (707) 547-1905 or connie.barton@scwa.ca.gov


Russian River County Sanitation District Emergency Force Main Project

Date Posted: 1/26/2022

Project Location: The project site is located next to the RRCSD Vacation Beach Lift Station at 17820 Orchard Avenue, southeast of the unincorporated community of Guerneville, California.

Project Description: The RRCSD will conduct emergency replacement of approximately 800 linear feet of pressurized sewer pipeline (force main). The replacement is necessary to avoid a failure of the force main that could result in the release of untreated sewage into the Vacation Beach residential neighborhood or mainstem Russian River.

View Notice of Exemption


Temporary Urgency Change Petition Notice of Exemption

Date Posted: 12/7/2021 

The Sonoma County Water Agency (Sonoma Water) is filing temporary urgency change petitions (TUCP) requesting that storage thresholds in Lake Mendocino be used as the hydrologic index to determine the water supply condition in the Russian River watershed.

These changes are necessary to ensure that the water supply condition and corresponding minimum instream flow requirements in the Russian River watershed are aligned with actual watershed hydrologic conditions.  This is essential to maintain sustainable reservoir/river operations to protect municipal water supply and listed salmon species in the Russian River. 

If you have any questions regarding this NOE, please contact Jessica Martini-Lamb at (707) 547-1903 or jessica.martini-lamb@scwa.ca.gov 

Notice of Exemption (PDF)


Santa Rosa Aqueduct and Russian River to Cotati Aqueduct Cathodic Protection Project

Notice of Determination: Posted December 15, 2021 

View Notice of Determination 

Initial Study and Mitigated Negative Declaration: Posted September 28, 2021

Public Review Period: September 29, 2021 to October 28, 2021 (CLOSED)

Sonoma Water is the Lead Agency under the California Environmental Quality Act (CEQA) for the Santa Rosa Aqueduct and Russian River to Cotati Aqueduct Cathodic Protection Project (Project). Sonoma Water has prepared an Initial Study and Mitigated Negative Declaration (IS/MND) for the Project in accordance with the California Environmental Quality Act (CEQA), the State CEQA Guidelines, and Sonoma Water’s Procedures for Implementation of CEQA. This notice is to announce that the IS/MND is available for review by the public, agencies, and interested parties.

Project Location: The Project is located within unincorporated areas of Sonoma County and the City of Santa Rosa, California at intervals along the Santa Rosa and Russian River to Cotati aqueducts. Locations of Project components start approximately 4 miles southwest of downtown Windsor and end approximately 4.5 miles north of Petaluma. Additional location information is available in the IS/MND.

Project Description: Sonoma Water owns, operates, and maintains a 48-inch diameter concrete mortar lined steel water supply pipeline (the Russian River to Cotati Aqueduct) and a 42-inch steel water supply pipeline (the Santa Rosa Aqueduct) that provide water from Sonoma Water’s production facility to southern parts of portions of central, southern, and eastern Sonoma County. The Russian River to Cotati and Santa Rosa aqueducts provide essential water service to approximately 600,000 residents and businesses within the Sonoma Water’s service area. The Project includes the construction of a total of 31 Cathodic Protection Stations and 49 Test Stations at intervals along the Santa Rosa and Russian River to Cotati aqueducts; vegetation maintenance activities associated with both aqueducts; and vegetation management at one location on the Petaluma Aqueduct. The Project is needed because the existing corrosion protection systems along the aqueducts are in need of replacement. Failing to replace the existing system components could result in corrosion and failure of portions of the aqueducts in the future.

Public Review: The 30-day public review period for the IS/MND closed on October 28, 2021. 

Materials: Hard copies of the Project documents linked below are available at Sonoma Water’s administrative office at 404 Aviation Blvd., Santa Rosa, CA. 

Notice of Availability / Notice of Intent to Adopt Initial Study and Mitigated Negative Declaration (PDF) - posted September 28, 2021

Draft Initial Study and Mitigated Negative Declaration (PDF) - posted September 28, 2021

Notice of Determination (PDF) - posted December 15, 2021

Final Initial Study and Mitigated Negative Declaration (PDF) - posted December 15, 2021

Public Comment Period for this Notice of Preparation closed on August 10, 2018.

View Notice of Preparation of Initial Study (PDF)

If you have any questions regarding this project, please contact Candace Messner at 707-524-6424 or candace.messner@scwa.ca.gov (preferred).


Wildfire Resilience at Spring Lake Regional Park Project 

Date Posted: August 17, 2021

Project Location: The project site is located at Spring Lake Regional Park, 5585 Newanga Avenue, in Santa Rosa, California

Project Description: The Wildfire Resilience at Spring Lake Regional Park Project (Project) proposes vegetation management activities and hazardous fuel reduction on high-risk public lands owned by the Sonoma County Water Agency (Sonoma Water).

The Project would include vegetation management for fire fuel reduction in accordance with California’s Wildfire and Forest Resilience Action Plan using funds administered by the California Coastal Conservancy. Work would include grazing by goats and vegetation management by hand crews. Hand crew work would include trimming and removal of overgrown vegetation and dead surface plant materials by cutting, removing, chipping on-site and/or mowing. Equipment would include hand tools and mechanized hand equipment such as string trimmers, chainsaws, pole saws, and/or chippers.
If you have any questions regarding this NOE, please contact Jessica Martini-Lamb at 707-547-1903 or jessica.martini-lamb@scwa.ca.gov

Notice of Exemption - filed August 17, 2021


Emergency Todd Road Well Activation Project 

Date Posted: June 18, 2021

Project Location: 4040 Todd Road, 0.5 mile west of Llano Road, Sonoma County, California

Project Description: The Sonoma County Water Agency (Sonoma Water) is proposing a drought emergency project to bring an existing groundwater well at the Todd Road Well Station (Well Station) into operation and to increase regional and community drought resiliency. The Well Station is located along the Russian River-Cotati lntertie Aqueduct (underground pipeline). The purpose of the project is to provide supplemental water from the existing well to support agriculture and public water retailers (cities and water districts) during the drought emergency. The project will consist of installing additional piping and associated equipment from the well to the main pipeline to ensure chlorine contact time regulatory requirements are met for potable water use. The new piping and appurtenances would be installed at and beneath the existing graveled hardscape area adjacent to the Aqueduct and well. Approximately 250 feet of 30-inch-diameter pipe would be installed. Total pipe length would be adjusted based on final procurement of pipe diameter. The 0.03-acre excavation area would be contained within the 0.13-acre work area on Sonoma Water property. The proposed project would not change the existing capacity of the Aqueduct or impact mature trees or native vegetation.

Notice of Exemption - filed June 18, 2021

If you have any questions regarding this NOE, please contact Dave Cook at (707) 322-8176 or david.cook@scwa.ca.gov


May 2021 Temporary Urgency Change Petition

Sonoma Water is filing a temporary urgency change petition (TUCP) requesting that the State Water Board make the following changes in the minimum instream flow requirements for the Russian River mainstem that are specified in Decision 1610 and Sonoma Water’s water right permits: (a) a Critical water supply condition minimum instream flow of 25 cubic feet per second (cfs) in the Upper Russian River from its confluence with the East Fork to its confluence with Dry Creek, and (b) a Critical water supply condition minimum instream flow of 35 cfs in the Lower Russian River downstream of its confluence with Dry Creek to the Pacific Ocean. The changes are necessary in order to maintain viable operations to support municipal use, protect listed salmon species, address water supply conditions at Lake Mendocino and Lake Sonoma, and prevent Lake Mendocino from declining to a storage level at which the reservoir may no longer be functional in light of the extremely dry hydrology the region has been experiencing since 2020.

Notice of Exemption – filed May 13, 2021

View TUCP webpage for more information


Russian River County Sanitation District (RRCSD) Sewer Main Repair Project

Date Posted: April 28, 2021
 
Project Location: The project site is located at 16451 River Road (Highway 116) in the unincorporated community of Guerneville, California, approximately 15 miles northwest of Santa Rosa in central Sonoma County.
 
Project Description: The project would replace approximately 60 linear feet of the existing sewer main collection pipe located between manholes M31-4 and M36-14 that has cracked and partially collapsed (Figure 1). The objective of the project is to replace the damaged section of pipe from approximately 9 feet upstream of M36-14 to approximately 69 feet upstream of M36-14. The area of disturbance includes approximately 9,000 square feet of land and would include approximately 80 linear feet of minor trenching within previously developed areas along the pipeline alignment. Previously developed areas consist of a gravel and dirt storage yard interspersed with ruderal non-native vegetation. Wastewater will be bypassed from a manhole upstream of the damaged section of pipe to a manhole downstream of the damaged section of pipe while the damaged section is being repaired. The bypass pipeline would be placed overland adjacent to the work zone. Project work will not result in an expansion of use.

Notice of Exemption: Russian River County Sanitation District (RRCSD) Sewer Main Repair Project, posted 4/28/21

If you have any questions regarding this NOE, please contact Jeff Church at 707-547-1949 or jeff.church@scwa.ca.gov


Rocky Ridge Temporary Precipitation Forecasting System Project

Date Posted: April 20, 2021

Project Location:  The project site is located at Rocky Ridge, off Bollinger Canyon Road, in Castro Valley, California

Project Description: The Project consists of a sublease agreement and temporary placement, operation, and maintenance of a precipitation forecasting system at Rocky Ridge, off Bollinger Canyon Road, in Castro Valley, California, with American Towers, LLC. The precipitation information system will improve the region’s early warning capabilities to avoid life-safety threats from potential land sliding, debris flows, flooding, erosion, road hazards or other fire related problems that could be compounded from heavy rain events. The temporary precipitation forecasting system also will give flood control managers, emergency responders, transportation officials, and media outlets more precise information on just where, when, and the intensity of expected rainfall.

If you have any questions regarding this NOE, please contact Connie Barton at 707-547-1905 or connie.barton@scwa.ca.gov

Notice of Exemption: Rocky Ridge Temporary Precipitation Forecasting System Project, posted 4/20/21


Water Transmission Pipeline Seismic Hazard Mitigation at the Santa Rosa Creek Crossing

Date Posted: February 2, 2021

Public Review Period: February 2, 2021 to March 4, 2021

Project Location: Located near the intersection of Sonoma Avenue and E Street, Santa Rosa, Sonoma County.

Project Description: An existing section of the Santa Rosa Creek Aqueduct crosses under Santa Rosa Creek and is at risk of failure during an earthquake due to liquefaction and lateral spread. The proposed project would help to reduce failure of this section of the Santa Rosa Aqueduct due to earthquake-induced liquefaction and lateral spread by relocating a section of pipeline (approx. 730 ft.) from the existing stream crossing to a location downstream under E Street and Sonoma Avenue. The relocated pipeline would use a trench-less technology to tunnel under the existing E Street Bridge and concrete box culvert into which the creek currently flows. The expected result is that the project would eliminate the Santa Rosa Aqueduct’s exposure to the free face of the creek and would help to reduce the risk of failure due to earthquake-induced liquefaction and lateral spread hazard at the existing pipeline stream crossing.
If you have any questions regarding this NOE, please contact Connie Barton 707-547-1905 or connie.barton@scwa.ca.gov

Notice of Exemption, posted 2/2/2021


Airport/Larkfield/Wikiup Sanitation Zone - Transfer, Treatment, Storage, and Disposal of Treated Wastewater

Date Posted: January 13, 2021

Public Review Period: January 13, 2021 to February 13, 2021

Project Location: The Airport/Larkfield/Wikiup Sanitation Zone (ALWSZ) treatment, storage, and disposal facilities in the unincorporated area northwest of Santa Rosa and the treatment, storage, and disposal facilities in the Town of Windsor and surrounding unincorporated area.

Project Description: The project comprises an agreement (Agreement) that will allow the ability to transfer recycled water and partially treated wastewater between the ALWSZ and the Town of Windsor treatment, storage, and irrigation facilities. The Agreement will allow for the coordinated operation of these systems for the purposes of increasing operating efficiencies, reducing operational costs, increasing beneficial use of recycled water, and decreasing discharges of recycled water to Mark West Creek, for an initial term of five years. The project may include the modification or installation of valves to existing wastewater and recycled water pipelines that will not result in an expansion of use. All project modifications will be conducted in existing roadways and within the footprint of the sanitation districts' existing facilities.

If you have any questions regarding this Notice of Exemption, please contact Jeff Church at 707-547-1949 or jeff.church@scwa.ca.gov

Notice of Exemption, posted 1/13/21


Riverfront Park Weir Repair Project

Date Posted: December 11, 2020

Public Review Period: December 11, 2020 to January 11, 2021

Project Location: The project site is located at Riverfront Regional Park at 7821 Eastside Road, approximately 3 miles southwest of the Town of Windsor, California, in central Sonoma County

Project Description: The project consists of the stabilization and re-armoring of the Lake Benoist weir at the southern end of Riverfront Regional Park. The weir, a bank stabilization feature that functions as a grade control structure between Lake Benoist and the Russian River, has eroded on the lakeside from high storm flows moving from the Russian River into Lake Benoist. High flows from the river overtopped the weir, eroded a previously installed hiking trail and created a large scour pit at the base of the outlet that is contributing to the destabilization of the weir. The project proposes to remove the damaged trail and utilize the trail material to fill in and regrade the scour pit. The trail will not be replaced due to repeated disturbance during overflow events. Re-grading would occur and the damaged weir area would be re-armored with rip-rap.

If you have any questions regarding this NOE, please contact Jeff Church at 707-547-1949 or jeff.church@scwa.ca.gov


Water Year 2021-2026 Major Planned Deviation to the Coyote Valley Dam – Lake Mendocino Water Control Manual

Date Posted: October 16, 2020
Public Review Period: October 16, 2020 to November 16, 2020

Project Description: The U.S. Army Corps of Engineers, San Francisco District (Corps) has conducted an environmental analysis in accordance with the National Environmental Policy Act of 1969, as amended. The final Environmental Assessment (EA) for the Water Year 2021 – 2026 Major Planned Deviation to the Coyote Valley Dam - Lake Mendocino Water Control Manual addresses a major deviation that would allow the Corps to store an additional 11,650 acre-feet of water above the existing guide curve, stipulated in the Coyote Valley Dam - Lake Mendocino Water Control Manual, for Water Year (WY) 2021 through WY 2026 between November 1 and February 28 in each year, with an option to begin the increase in spring storage on February 15, to restore some of the diminished water supply reliability without reducing the existing flood protection capacity of Lake Mendocino in the County of Mendocino, California. The Final EA evaluated alternatives that would improve water supply reliability without reducing the existing flood protection capacity of Lake Mendocino in the study area. 

The document is also available for review at:

  • US Army Corps of Engineers’ office at Lake Mendocino; and
  • Sonoma County Water Agency 404 Aviation Blvd. Santa Rosa, CA, 95403.

In addition, please call 707-547-1900 to request a copy of the draft EA by mail.

Public Review: The 30-day public review period for the draft Environmental Assessment closed November 16, 2020. Specific responses will also be included in a comments and responses appendix to the final document.


Vortex Tube Rehabilitation Project

Date Posted: August 28, 2020
Notice of Determination - posted November 18, 2020
Public Review Period: August 28, 2020 to September 28, 2020
The Sonoma County Water Agency (Sonoma Water) is the Lead Agency under the California Environmental Quality Act (CEQA) for the proposed Vortex Tube Rehabilitation Project (Proposed Project). Sonoma Water has prepared an Initial Study and Mitigated Negative Declaration (IS/MND) for the project in accordance with the California Environmental Quality Act (CEQA), the State CEQA Guidelines, and Sonoma Water’s Procedures for Implementation of CEQA. This notice is to announce that the IS/MND is available for review by the public, agencies, and interested parties. Instructions for submitting comments on the document are included in this notice.

Project Location: The Proposed Project site is located on Santa Rosa Creek where it flows beneath Montgomery Drive, approximately 4 miles east of downtown Santa Rosa and approximately 3/4 mile east of Spring Lake Regional Park.

Project Description: The Vortex Tube is part of the Santa Rosa Creek Diversion Structure, a concrete flood control facility constructed in 1963 as part of the Central Sonoma Watershed Project to reduce flooding in downtown Santa Rosa. A concrete culvert beneath Montgomery Drive, known as the Vortex Tube, regulates peak winter floods in Santa Rosa Creek. The Vortex Tube has been damaged by abrasion during high flows. The purpose of the Proposed Project is to extend the useful life of the Vortex Tube by restoring its structural integrity.

The Proposed Project’s repair of the Vortex Tube would be implemented in two phases: 1) construct a permanent Bypass Pipe beneath Montgomery Drive to temporarily direct creek flows around the Vortex Tube, and 2) dewater and repair the damaged Vortex Tube. The Proposed Project would not change the function or expand the capacity of the Diversion Structure.

Materials: A copy of the IS/MND and supporting materials are available at the Sonoma Water administrative office at 404 Aviation Blvd., Santa Rosa, CA.

Public Review: The 30-day public review on the IS/MND closed September 28, 2020.

Notice of Availability / Notice of Intent to Adopt Initial Study and Mitigated Negative Declaration

Draft Initial Study and Mitigated Negative Declaration

Notice of Determination - posted November 18, 2020


Dry Creek Habitat Enhancement Project, Miles 2-6 - Draft Environmental Impact Report

Sonoma Water, as Lead Agency, has prepared this Draft Environmental Impact Report (EIR) for Dry Creek Habitat Enhancement Project, Miles 2–6 (proposed project) to provide the public and responsible and trustee agencies reviewing the Dry Creek Habitat Enhancement Project an analysis of the potential effects, both beneficial and adverse, on the environment. This project is intended to fulfill federal mandates to implement habitat enhancement within Dry Creek to create both winter and summer rearing habitats for juvenile steelhead and coho salmon, with an emphasis on improving habitats for the survival of juvenile coho salmon while allowing Sonoma Water to maintain the existing flow range in Dry Creek for water supply purposes.


Fish Habitat Flows and Water Rights Project - Draft EIR

On August 19, 2016, Sonoma Water released the Fish Habitat Flows and Water Rights Project (Fish Flow Project) Draft Environmental Impact Report (DEIR) for public review. The Fish Flow Project DEIR describes the Proposed Project, the purpose of the project, why it is necessary and the potential environmental impacts of the project.

The Fish Flow Project has five purposes:

  1. Comply with National Marine Fisheries Service’s Russian River Biological Opinion, which requires Sonoma Water to ask the State Water Board to lower minimum instream flow requirements in the Russian River and Dry Creek in order to improve conditions for coho and steelhead.
  2. Improve conditions for threatened Chinook salmon, by better preserving cold water in Lake Mendocino, which can be released for the fall Chinook migration.
  3. Replace a measuring requirement in Sonoma Water's water right permits, called the “hydrologic index,” to better reflect conditions in the Russian River watershed.
  4. Extend to 2040 Sonoma Water ’s right to divert and re-divert 75,000 acre feet of water annually, in order to ensure a reliable water supply for more than 600,000 people.
  5. Add existing points of diversion for Occidental Community Service District and the Town of Windsor as authorized points of diversion in Sonoma Water’s water right permits. (Sonoma Water has agreements with specific entities, including Occidental and Windsor, that authorize them to divert water from the Russian River under Sonoma Water’s water right permits using their own facilities. The proposed change would allow these entities to report water diverted through these existing points of diversion under Sonoma Water’s water right permits, and would not increase the total amount of diversions.)

View the Fish Flow Project Page for more information


Green Valley Creek High Flow Channel Project

Sonoma Water has developed a proposal to reduce flooding on Green Valley Road west of Graton by removing sediment from the adjacent Green Valley Creek and restoring the creek banks with native vegetation. Pursuant to the California Environmental Quality Act, Sonoma Water released a Draft Initial Study and Negative Declaration (IS/ND) for the project on June 22. The public is invited to provide comment on the project before July 24.

Green Valley Creek experiences recurring flooding, leading to extended road closures or hazardous driving conditions on Green Valley Road, stranded fish and wildlife species, and damage to the roadway and adjacent farmland. In recent years, flooding has become worse, lasting longer, causing more damage, and occurring with greater frequency. The proposed project would excavate and maintain channels in the creek and install native plants along the banks to reduce flooding of Green Valley Road and nearby properties and improve aquatic habitat. The project is expected to be implemented in fall 2018. Annual dry season maintenance would occur as needed for five years.

“Last year, Green Valley Road was closed for over three weeks due to flooding,” said Sonoma Water Director Lynda Hopkins. “The project would make Green Valley Road safer for the communities who rely on it, as well as the fish and wildlife who rely on the creek.”

The project would involve clearing blackberry understory from the creek and an adjacent area in order to establish a temporary access road across a dry channel; excavating sediment from the existing creek and installing a high flow channel through a gravel bar; and planting native species along its banks. Although construction is likely to temporarily disturb fish and wildlife, over the long term the project would improve fish passage, reduce the number of fish stranded by receding floodwaters, improve habitats for other aquatic species, and support healthier habitats downstream by decreasing sediment flows from the area.

An electronic copy of the Draft IS/ND is available at www.scwa.ca.gov/environmental-documents. Hard copies of the Draft IS/ND are available for purchase by request at 707-547-1900 or at Sonoma Water’s administrative office (404 Aviation Boulevard, Santa Rosa). Hard copies are also available for public viewing at the following locations:

Sonoma Water: 404 Aviation Blvd Santa Rosa, CA 95403

Sebastopol Regional Library: 7140 Bodega Avenue, Sebastopol, CA 95472

An Initial Study is a preliminary analysis of a project’s potential environmental impacts used to determine whether a Negative Declaration or an Environmental Impact Report will be prepared. The Initial Study is intended to provide a clear understanding of the environmental impacts associated with the construction and operation of the proposed project for decision-makers, responsible and trustee agencies under CEQA, and the public. If an Initial Study identifies potentially significant impacts but the project is modified or revised to clearly mitigate the impacts, a Mitigated Negative Declaration may be prepared. If an Initial Study concludes that a project may have a significant effect on the environment, an Environmental Impact Report should be prepared.

Download Notice of Availability

Initial Study

There have been several previous studies in Green Valley Creek watershed by the Gold Ridge Resource Conservation District. These past studies include evaluating flooding along Green Valley Road. For more information, visit the Gold Ridge Resource Conservation District website.


Bay Area Integrated Regional Water Management Plan 2019

Notice of Exemption (Sonoma Water) - Posted 6/10/20

Notice of Exemption (Sonoma Valley Count Sanitation District) - Posted 6/10/20


Mark West Creek Crossing Project: Russian River-Cotati Intertie Pipeline Seismic Hazard Mitigation

The purpose of the Project is to reduce potential pipe failure and loss of water supply service resulting from permanent ground deformation caused by a moderate or severe earthquake along the Rodger’s Creek Fault. To maintain safe and reliable water service during a seismic  event, the Project would modify the Russian River-Cotati Intertie to improve its ability to withstand the effects of ground deformation,
liquefaction, and lateral spread hazards. The project consists of installation, operation, and maintenance of approximately 767 linear feet of a 48-inch diameter steel pipeline segment across the Mark West Creek channel (Figure 2). The new pipeline segment would replace the existing pipeline segment beneath the creek channel and would be installed parallel to (and within 25 feet of) the existing pipeline and buried 6 to 8 feet deeper than the existing pipeline. The existing pipeline segment would be disconnected, filled with a low strength concrete mixture, and abandoned in place. The new pipeline segment would tie into the existing 48-inch diameter Russian River-Cotati Intertie pipeline.


Russian River Crossing Project: Russian River - Cotati Intertie Pipeline Seismic Hazard Mitigation

Sonoma Water owns, operates, and maintains a 48-inch diameter steel water supply pipeline (referred to as the Russian River-Cotati Intertie) that crosses the southern and eastern aqueduct transmission lines and crosses the Russian River in Sonoma County. The pipeline is buried at a relatively shallow depth (approximately 7 feet below ground surface) across the Russian River channel and stream banks, and crosses seismically unstable terrain.

The Local Hazard Mitigation Plan (LHMP) identifies the Russian River-Cotati Intertie Intertie crossing of the Russian River as vulnerable to potential ground deformation, liquefaction, and lateral spread resulting from strong ground shaking in the soil at or below the elevation of the pipeline. The LHMP states that pipeline failure from an earthquake would isolate the Mirabel collector wells from the Russian River-Cotati Intertie Intertie Pipeline.

The proposed project is needed to address seismic concerns related to reliable delivery of water to Sonoma Water’s service area and prevent the loss of an essential water service due to a moderate or severe earthquake along the Rodger's Creek/Hayward Fault.


Russian River Estuary Management Project - EIR

View Project Page for more information


Sonoma Valley County Sanitation District Sewer Trunk Replacement Project, Reaches 4A, 4B, and 4C

The Proposed Project would repair and improve a portion of the District’s existing sewer trunk main to reliably handle dry and wet weather inflows. The Proposed Project would include the following components: (1) abandon and/or remove and replace sections (approximately 8,500 linear feet) of the existing 21-inch diameter reinforced concrete underground sewer trunk main with 27-inch polyvinyl chloride pipe, including sections of connecting sewer lines, manholes and other appurtenances; (2) restore roadway surface; (3) relocate, reconstruct, or remove miscellaneous structures; and (4) relocate, install, or abandon other utilities. The Proposed Project would occur in three phases over approximately a three-year period, beginning in 2019.  The public review period closed at January 7, 2019. Learn more about the proposed project.


Stream Maintenance Program - EIR

View SMP webpage for more information