State approves creation of Atascadero groundwater sub-basin

Atascadero is now officially home to a new groundwater sub-basin, which North County officials say will allow for them to better manage water, particularly during drought.

The city announced this week that the California Department of Water Resources granted a request from the Templeton Community Services District to establish the sub-basin separate from the Paso Robles groundwater basin, with the Rinconada Fault as a boundary.

California’s Sustainable Groundwater Management Act, which was passed in 2014, allows communities to ask for a modification of groundwater basin boundaries. The Templeton CSD applied in March to establish a separate basin.

Atascadero Mutual Water Company general manager John Neil and Templeton CSD general manager Jeff Briltz said the communities pushed for the change because of the differences between the Atascadero area — where customers draw about half their water from the sub-basin — and the Paso Robles area.

“The Atascadero area behaves quite differently,” Briltz said.

According to the Templeton CSD’s application, about 16,000 acre-feet of water is drawn from the sub-basin for use each year. About 12,000 acre-feet of that water, or 75 percent, is provided to customers in urban areas. The remaining 4,000 acre-feet serves agricultural, rural residential and commercial uses.

Customers who access the Paso Robles basin use 75,000 acre-feet of water per year. About 60,000 acre-feet, or 80 percent, is used for agriculture, with the remaining 15,000 acre-feet going to rural residential, commercial and municipal uses.

Neil said Atascadero-area customers, most of whom use their water for residential purposes, can cut back on their consumption during a drought. Many Paso Robles-area customers use their water for agriculture, which means they’ll use more water during a drought, not less.

“Our response to a drought is totally different,” Neil said.

Water levels in the Atascadero sub-basin — which is more easily recharged with rainwater — have also remained relatively stable during the drought, while Paso Robles basin water levels have declined steadily, according to hydrographs taken in both areas.

With the establishment of the sub-basin, stakeholders such as the Templeton CSD, the Mutual Water Company, the cities of Atascadero and Paso Robles and San Luis Obispo County, will come together to create a groundwater sustainability agency.

Briltz and Neil said this arrangement will allow for better collaborative management, especially during a drought.

“We’ll have an idea what our reaction will be if we do see a decline in groundwater levels,” Neil said.

This story was originally published October 21, 2016 at 7:36 AM with the headline "State approves creation of Atascadero groundwater sub-basin."