Southern California is taking a big step forward on protecting water supplies as it increases use of recycled water.

A historic 30-year recycled water purchase agreement eliminates the need to bring water in from Northern California and the Colorado River to recharge groundwater.

The agreement is signed by the Water Replenishment District (WRD) of Southern California and the Sanitation Districts of Los Angeles County.

"Both WRD and the County Sanitation Districts have been at the forefront of the recycled water industry which benefits our whole basin to recharge clean water into our aquifer, and they will continue to serve as we encounter warmer climate and drought cycles. They are an integral component in the water supply and management portfolio for our Southern California area, state and our nation," says Representative Grace Napolitano (D-CA).

"The action we took today is the final step in WRD's 50-year march toward independence from imported water for the purpose of replenishing the groundwater supply. Fifty years ago, WRD was the single largest customer in Southern California for water imported from the Colorado River. In a few short years, with the completion of WRD's Groundwater Reliability Improvement Program (GRIP), we will not be a customer at all," says WRD Board President Rob Katherman.

Historically, WRD has purchased over 16 billion gallons of recycled water and 7 billion gallons of imported water a year to replenish groundwater. This agreement allows WRD to use only recycled water, totaling 23 billion gallons a year - enough to serve 142,000 families of four.

This week, Southern California's Metropolitan Water District approved rebates for rain barrels and home soil moisture sensor systems as well as financial incentives for retrofitting fitness centers with high-efficiency toilets and urinals. Other measures approved increase the use of recycled water.

"We have reached an era of limits on the amount of water we can import from Northern California and the Colorado River, so we must explore any and all options to maximize local resources," General Manager Jeffrey Kightlinger says. "The next generation of water resources will be developed locally to add to the 1.2 billion gallons of water produced in our region each day through water efficiencies, recycling and groundwater clean-up projects."

In 2008, Los Angeles Mayor Antonio Villaraigosa unveiled a water plan for the city that for the first time centered on recycled water.

Dumping Fossil Fuel Investments

Another California water district, Santa Clara Valley Water District in San Jose, unanimously voted to divest from its investments in fossil fuels and ban future investments in the largest 200 coal, oil and natural gas companies.

The district supplies 1.8 million residents. It joins Berkeley, San Francisco and Richmond, California, and Seattle, Washington and Portland, Oregon.

Learn about recycled water projects in California: