Monterey's Coastal Water Project

The Coastal Water Project is California American Water’s proposed solution to the Monterey Peninsula’s water supply shortage. The project consists of a seawater desalination plant and aquifer storage and recovery facilities. The project will replace water pumped from the Carmel River upon which the community has come to rely.

The project is based upon the recommendation by an independent team of environmental consultants selected by the California Public Utilities Commission (CPUC) of how to best meet the community’s water supply needs. After a series of public hearings and workshops, the Coastal Water Project was suggested as the best alternative to a long-debated new dam and reservoir on the Carmel River.

The CPUC is reviewing California American Water’s project application. They have prepared an Environmental Impact Report which looks at California American Water’s proposed project and two alternative projects. Key features of the proposed projects include:

-        A 10  MGD Seawater desalination facility

-        Aquifer Storage and Recovery Facilities

-        Conveyance Pipeline

-        Storage Reservoirs

-        Pump Stations and connections to existing infrastructure

The CPUC expects to release a final version of their report at the end of October, 2009 and to certify that report no later than January of 2010.  A vote on the Certificate of Convenience and Public Necessity, the permit required from the CPUC, is scheduled for May of 2010.

Upon approval from the CPUC, we will proceed with applications for additional permits from federal, state and local agencies as well as detailed design work. Construction of the project is anticipated to be complete in 2015.

Background

Unlike many communities in California, the Monterey Peninsula does not import water from the Sacramento Delta or Colorado River. Instead, in its semi-arid climate, the peninsula community is completely dependent on local rainfall for its water supply.

The Carmel River has served as the main source for the Monterey Peninsula’s water supply since the first dam was built on the river in the late 1890s. California American Water traditionally supplied its customers with water from wells located near the river in the Carmel Valley Aquifer. The water supplied was considered to be groundwater, which is not subject to State Water Resources Control Board (SWRCB) jurisdiction. However, in 1995, the SWRCB ruled that California American Water’s wells were diverting from the underflow of the Carmel River, thus making the diversion subject to SWRCB jurisdiction. Order 95-10 was adopted, which held that California American Water had no valid permits for nearly 70 percent of the community’s water supply. 

Supply restrictions increased in 2006, when as the result of a court adjudication process, cutbacks were ordered in the Seaside Groundwater Basin, the Monterey Peninsula’s only other water source.

In 2008, the  SWRCB issued a draft Cease and Desist Order proposing additional cutbacks to the community’s water supply. Since that time, the SWRCB has received public testimony and revised its order. They are expected to vote on their latest proposal in October 2009.

While California American Water and its customers have managed to decrease water consumption by more than 20% through conservation, conservation efforts alone cannot fully address the water supply issues faced by the Monterey Peninsula community. California American Water advocates a water solution that combines conservation, best management practices, use of alternative water sources and development of a new, sustainable water supply.

Technology

Seawater desalination is used in 120 countries around the world for drinking water. As the technology has improved and costs have lessened, communities in the United States are increasingly looking toward desalination for additional water supplies, or to replace use from over-stressed rivers and aquifers. 

Desalination is accomplished through a Reverse Osmosis (RO)  process in which seawater is sent through highly pressurized, fine membrane filters that remove salt and other contaminants. What’s left is pure H20, which is why many bottled water companies use RO filters to produce their product.

California American Water is currently operating a pilot desalination plant at the Moss Landing Power Plant. The pilot plant functions as a mini version of a seawater desalination plant. It draws 22,000 gallons of ocean water per day from the power plant’s cooling systems and tests a variety of membrane and treatment technologies to help refine design of the full-scale project. Desalinated water produced by the pilot plant is also tested for more than 100 compounds as part of a 12-month water quality study that will be completed in December of 2009 and submitted to the Department of Public Health as part of the project permitting process. The data collected in this study will be valuable to the ultimate project, regardless of its location. All of the water produced by the pilot plant is returned to the ocean through the power plant’s outfall.

Aquifer Storage and Recovery (ASR) captures excess flows from the Carmel River during the rainy season and stores them in natural underground aquifer for withdrawal during the dry summer months. Beginning phases of this component of the Coastal Water Project are already underway through a partnership between the Monterey Peninsula Water Management District and California American Water.

Environment

The Coastal Water Project will enable California American Water to reduce its pumping from the Carmel River and the over-drafted Seaside Groundwater Basin. Environmental and fisheries groups concerned about the threatened South-Central California Coast steelhead trout found in the Carmel River have sought reductions in community’s use of the Carmel River as its primary water source. California American Water and the Monterey Peninsula Water Management District conduct programs on the river to protect the steelhead and their environment. California American Water maintains fish ladders and traps on their two existing dams, which help fish to traverse the river unimpeded.

Pumping reductions from the Seaside Groundwater Basin will also be achieved with a desalination project and will combat the threat of seawater intrusion, which can occur when aquifers are overdrawn and water levels become too low. Sustainable use of our natural water sources is essential to protect the environment and our precious water resources. 

Finally, water conservation is an important supply component of the Coastal Water Project. Residents of the Monterey Peninsula use 70 gallons of water per person per day – approximately half of the water consumed by the average Californian. Conservation programs have been in place on the Monterey Peninsula for decades, both to benefit the environment and to help manage the limited water resources of this drought-prone community. The Coastal Water Project anticipates that water wise practices will continue in Monterey, even after a reliable supply is secured.