January 11, 2018
Water-saving measures in California (click here) have also led to substantial reductions in greenhouse gas (GHG) emissions and electricity consumption in the state.
That is the conclusion of new research from the University of California, Davis, published today in the journal Environmental Research Letters.
Measures to cut water use by 25 per cent across California were implemented in 2015, following a four-year drought in the state that caused the fallowing of 542,000 acres of land, total economic costs of $2.74 billion, and the loss of approximately 21,000 jobs.
The UC Davis researchers found that, while the 25 per cent target had not quite been reached over the one-year period -- with 524,000 million gallons of water saved -- the measures' impact had positive knock-on effects for other environmental objectives.
In California, the water and energy utility sectors are closely interdependent. The energy used by the conveyance systems that move water from the wetter North to the drier and more heavily populated South -- combined with utility energy use for treatment and distribution, end-user water consumption for heating, and additional pumping and treatment -- accounts for 19 per cent of total electricity demand and 32 per cent of total non-power plant natural gas demand state-wide.
Lead author Dr Edward Spang, from UC Davis, said: "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). Interestingly, those savings were around 11 percent greater than those achieved by investor-owned electricity utilities' efficiency programs over the same period.
"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."...
