A sentence in the Bay Delta Conservation Plan draft EIR puzzled me:
“The city of Stockton depends almost entirely on groundwater for its municipal and industrial water needs.” (See Page 11 of Chapter 7)
In reality, Stockton has now tapped all four of the major streams in San Joaquin County. Stockton East diverts the Calaveras River; the district contracts with the feds for Stanislaus River flows; the city takes Delta water off the San Joaquin River thanks to the new $220 million Delta Water Supply Project; and it buys Mokelumne River water from the Woodbridge Irrigation District.
That’s a pretty diverse portfolio.
“We’re told our story over and over again about how we (the city, CalWater and the county), since 1977, have reduced our reliance on groundwater to meet our needs in the Stockton Metropolitan Area,” said Bob Granberg, deputy director of Stockton’s Municipal Utilities Department.
In 2000-01 groundwater accounted for about 38 percent of the city’s water supply. That number nudged up a bit to a peak of 42.7 percent in 2004-05, but has since declined significantly. 2012-13 was the lowest year yet, with just 14.8 percent of Stockton’s water coming from below ground.
And the Delta Water Supply Project wasn’t even in service for that entire year.
Big picture: The less we rely on groundwater, the more likely it will be available to help us during extended droughts. A healthy groundwater table beneath the city can also help prevent the intrusion of saltier water from beneath the Delta.
“It would be safe to say we would get below 10 percent (groundwater use) in the coming years,” Granberg said.