Dec 31, 2009

Annual Program to Store Winter River Flows Begins

California American Water and Monterey Peninsula Water Management District inject excess Carmel River flows into Seaside groundwater basin for summer withdrawal

California American Water and the Monterey Peninsula Water Management District began annual operations of their joint Aquifer Storage and Recovery (ASR) project this month. The ASR project diverts excess water from the Carmel River that would otherwise flow to the Pacific Ocean, and stores the water in the Seaside groundwater basin. High flows in the river typically occur during the winter when the Monterey Peninsula receives the majority of its rainfall. During the dry, summer months when river flows are low and pumping is restricted, the stored water serves as an alternate source of supply.

"This program has tremendous environmental benefits," said Craig E. Anthony, general manager of California American Water. "It enables us to manage our pumping of the Carmel River aquifer in a way that most benefits the river and its habitat, including the threatened Central Coast steelhead trout."

Pumping for the ASR program began in December when river flows reached approximately 190 cfs, and has since been gradually increased to full capacity.

California American Water and the Monterey Peninsula Water Management District began testing the ASR project in 1998. Two ASR wells have already been drilled by the district in the Seaside Basin and have been in operation since 2008. In 2009, California American Water constructed a new pipeline that allowed the full, permitted potential of excess Carmel River water to be captured and injected into the basin in the winter. It is estimated that an average of 900 acre ft per year of ASR water could now be supplied by the project.

"ASR is key to resolving the Monterey Peninsula's water supply shortage," said Monterey Peninsula Water Management District General Manager Darby Fuerst. "Like the development of new water supplies such as desal, and improved water conservation, ASR is a critical component of our future supply."

Based on the success of the ASR program, California American Water and the Monterey Peninsula Water Management District are working cooperatively to expand the facilities by drilling two additional wells near Fitch Middle School in Seaside, which would double the project's yield.

California American Water is charged by the state to develop an additional water supply of more than 10,000 acre ft per year to replace current pumping from the Carmel River and the Seaside Basin. A project to accomplish this, which includes a desalination facility, is currently under review by the California Public Utilities Commission, which certified its Environmental Impact Report for the project on Dec. 17, 2009.