The City of Santa Rosa is the managing partner of the Santa Rosa Subregional Reclamation System, which reclaims water and distributes it on behalf of the Cities of Cotati, Rohnert Park, Santa Rosa, and Sebastopol, and portions of the unincorporated area of Sonoma County. The City treats water to a tertiary level. More than 50 percent of this reclaimed water (nearly 4 billion gallons annually) is used to irrigate approximately 5,700 acres of farmlands, including pastures, hay crops, vineyards, and row crops. The reclaimed water is also used to irrigate golf courses, parks, school grounds, and both public and private urban landscaping. This is one of the largest reclaimed water agricultural irrigation systems in the country. All of the water produced during the summer months is used for irrigation, and all of the winter water that can be stored is saved for irrigation for the following summer.

During winter when there is no demand for irrigation and all of the storage ponds are full, the system's remaining water is discharged to the Russian River. The North Coast Regional Water Quality Control Board limits these discharges to an amount not-to-exceed 5 percent of the River flow. In dry years, when the river is flowing at a very low rate, the system could exceed the allowable flow in violation of the conditions of the City's National Pollutant Discharge Elimination System (NPDES) permit.

The Geysers Recharge Project has been selected by the City as its solution to the above stated problem. The project will transport eleven million gallons per day of reclaimed water to The Geysers steamfield for the generation of electricity. This cooperative effort between the City, the State Lands Commission, and Calpine Corporation (operators of The Geysers steamfield) will benefit both the public and private industry. The project will also provide expanded long-term water reuse opportunities for the Subregional System, as well as future reuse opportunities for other agencies such as Windsor, Healdsburg, and the County of Sonoma.

In addition to the current reclamation system, The Geysers project will allow additional future reuse of reclaimed water, and making additional water available for future agricultural irrigation in the Alexander Valley and other portions of the county. Expanded irrigation will decrease the draw-down of water in Russian River tributaries, helping to restore habitat for two species listed as "threatened" under the Endangered Species Act--steelhead and coho salmon.

The City completed an exhaustive 5-year study program, evaluating all reasonable alternatives. The City certified the Final EIR and selected The Geysers Recharge alternative. Construction took place in 2000 and 2001 and will take place in 2002 with full operation beginning in 2003.

The Geysers Recharge Project required sound engineering and technology, involving the construction of a 34-mile, 24-to-48-inch diameter underground pipeline from Santa Rosa’s Delta Pond up to The Geysers storage tank at a ridge overlooking The Geysers steamfield. From there, the water will flow by gravity and then will be injected into underground wells at depths of 4,000 to 11,000 feet. In time, this water will be naturally heated to produce a clean "dry" steam that will then be utilized in nearby electrical power plants to become an environmentally friendly, reliable source of energy.

Ameron International's Water Transmission Group was successful in supplying the majority of the pipeline for The Geysers Project and specifically the entire 48-inch diameter pipe. In the past few years, Ameron's Tracy, CA plant has manufactured and delivered over 114,000 linear feet of Cement Mortar Lined, Tape Wrapped and Mortar Coated Steel Pipe to the Standards of AWWA C200, C205 and C214 as specified by CH2M Hill and Winzler & Kelly, the engineering consultants. A mortar coating per AWWA C205 was applied in addition to the tape wrapped coating per AWWA C214 in order to provide a rock-shield or armor-coat for the dielectric tape and avoid damage during transportation and installation. A Carnegie bell and spigot rubber gasket joint was specified over the rolled groove rubber gasket joint because of its superior ease of installation and water tightness qualities. Ameron has two additional contracts to complete in 2002 for about 46,000 linear feet of 48-inch diameter pipe.

The project uses 11 million gallons a day (mgd) of Santa Rosa’s reclaimed water, which is about half of the Laguna Treatment Plant’s average dry weather flow. The 11 mgd rate will partially replenish the steamfield with water and eventually increase electrical output by about 85 megawatts–enough to provide for the energy needs of 116,000 residents.

This project is a unique public/private partnership between the City of Santa Rosa and geothermal steamfield operators, Unocal and Calpine. The City of Santa Rosa will construct a pipeline from Santa Rosa to the Geysers. Private industry will construct the pipeline and distribution system within The Geysers, power transmission facilities, and well conversions to allow for injecting water. The private/public partnership agreement is designed as a 30-year commitment for injecting water at The Geysers.

The partnership between the City and private industry makes this project economically feasible for the ratepayers. It also provides the added economic benefit of extending the life of the steamfield operation, which continues to be a major source of property taxes, employment, and economic activity in Sonoma County.

The Geysers Recharge Project is designed to offer maximum flexibility within the structure and long-term planning afforded by a permanent pipeline. The City has chosen to increase the pipeline size to the Alexander Valley, a premium wine grape growing region. This will allow the City to offer water to vineyards and other agriculture users along the route. Although water will be available for potential new agricultural uses, the existing users, with property totaling approximately 5,000 acres, will not be adversely impacted by this project.

The Geysers Recharge Project also offers year-round, weather-independent reuse capability. The pipeline’s large capacity will:

Reduce winter discharge to the Russian River

Accommodate future population growth, providing an opportunity to serve future agricultural needs

Provide a high level of water management reliability through a variety of reuse options

Geothermal steam is one of the most environmentally benign forms of energy production. By injecting reclaimed water to replenish underground steam wells, the City of Santa Rosa is establishing a safe, clean, and environmentally advanced method of treated wastewater reuse. The underground pipeline will follow a route designed to minimize visual and other environmental impacts. The plan will meet the standards of the North Coast Regional Water Quality Control Board while also providing a source of electrical energy that offers advantages over natural gas-fired power plants.

By extending the life of the steamfield, the Geysers Recharge Project will help assure that the environmental benefits will continue into the future. In the long term, the project will provide a way to continue supporting agriculture in Sonoma County. As water rights become more contested in California, this water will provide a valuable alternative to taking water from the Russian River or its tributaries. Additionally, water will be transported to river tributaries by an expanded irrigation system to help restore habitat for two species listed as "threatened" under the Endangered Species Act.