California water conservation brings other environmental benefits

Researchers at the University of California, Davis are reporting that water conservation measures in the state of California have also significantly reduced electricity consumption and greenhouse gas (GHG) emissions.

In 2015, following four years of severe drought, California implemented new water regulations with a target of cutting overall water usage by 25 percent.

The investigation from UC Davis established that 524,000 million gallons of water were saved in the first year of conservation efforts, which was a bit shy of the state’s goal of a 25 percent reduction. However, the experts also found that the new water regulations were helping to address other environmental issues.

The water and energy systems in California are closely interconnected. The energy used to move, treat, and distribute water accounts for 19 percent of the state’s total electricity demand.

“Due to this close interdependence, we estimated that the decrease in water usage translated into a significant electricity saving of 1,830 gigawatt hours (GWh),” said lead author Dr. Edward Spang.

The study authors noted that the energy savings which resulted from water reduction were around 11 percent greater than those savings which resulted from investor-owned electricity utilities’ efficiency programs within the same time frame.

“In turn, we calculated that the GHG emissions saved as a direct result of the reduction in electricity consumption are also significant – in the region of 524,000 metric tons of carbon dioxide equivalent (CO2e). That is the equivalent of taking 111,000 cars off the road for a year,” said Dr. Spang.

“The scale of these integrated water-energy-GHG savings, achieved over such a short period, is remarkable,” said study co-author Professor Frank Loge. “Even more interesting is that the cost of achieving these savings through water conservation was competitive with existing programs that specifically target electricity or GHG reductions.”

Professor Loge said that the findings of this study strongly support the addition of water conservation to the growing collection of ideas on how to effectively reduce energy consumption and harmful emissions.

“Taking these three benefits into consideration together would substantially increase the cost-effectiveness of water-focused conservation programs across all scenarios of varying program and technology persistence,” said Professor Loge.

“There is a strong incentive for water and energy utilities to form partnerships, and identify opportunities to secure these combined resource savings benefits at a shared cost. There would also be a benefit in the associated regulatory agencies supporting these partnerships through aligned policy measures, and targeted funding initiatives.”

The study is published today in the journal Environmental Research Letters.

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By Chrissy Sexton, Earth.com Staff Writer