Rainfall Marks Great Finish for Palo Alto's Water Year

As many governments reach the end of their fiscal year this month, another kind of year–the “water year”–will also come to a close.

Fortunately for Santa Clara County, it has been a wet one.

“Everyone is above normal this year,” said Steve Anderson, meteorologist at the region's National Weather Service office in Monterey.

After unusual late-June weather dumped 0.51 inches of rain in Palo Alto in the last 48 hours, the weather service's long-term monitoring center in San Jose showed 114 percent of normal rainfall, up nearly half an inch from the 15.08 inches of rain last year, according to data from the agency.

Locally, rains showed even greater gains at 129 percent of normal, according to the NWS climate station in Mountain View. 14.90 inches fell at the station there this year, up from 13.35.

Even without the freak rainstorm on Tuesday, the county’s water supply will enter the next water year on a high note after two years of severe drought, said Marty Grimes, spokesman for the Santa Clara Valley Water District.

“It’s an indication of a really good year that we can actually store water outside of the county,” he said.

The reservoir system is currently at 69.1 percent of its 38.1 billion-gallon capacity, according to the water district. Steven’s Creek Reservoir showed a level slightly higher than 100 percent on Wednesday morning, with three more reservoirs in the 90s and all above 50 percent.

Water that exceeds the district’s storage capacity at any given time is sent to a kind of water “bank account,” the Semitropic Water Storage District near Bakersfield. The water district receives credit for its contribution that it can redeem for water from non-local sources, said the spokesman.

As of April 30, the district had sent 147 percent of its total reservoir capacity to the reserve, according to material from the water district.

Five reservoirs currently have their storage limited as much as 50 percent while undergoing seismic inspection, according to the water district. Had that not been the case, total storage for the system might have been even higher.

The heavy rains have renewed and again raised interest in , which

Roughly half of the county’s water supply comes from local sources, split evenly between underground aquifers and the network of reservoirs spread throughout the region, according to information from the water district.

The remaining portion of the county’s water ultimately comes from sources like the Sacramento–San Joaquin River Delta. Sierra snowpack feeds the delta, a kind of natural water storage system that stood at 293 percent of average as of Wednesday morning, according to the California Department of Water Resources.

On March 30 of this year, Governor Jerry Brown called an end to a state drought declaration in 2008 that became a California-wide state of emergency mandating water conservation in Feb. 2009.

“While this season’s storms have lifted us out of the drought, it’s critical that Californians continue to watch their water use,” Brown said in March, “Drought or no drought, demand for water in California always outstrips supply. Continued conservation is key.”

Grimes said that the county’s heavy reliance on delta water has many officials concerned. State-mandated protection of species like the Delta Smelt could force a shutdown of the pumps used to supply delta water at any time.

“That’s a risk any year,” he said.