Despite a year with half the average rainfall, the San Benito County Water District estimates the current groundwater levels and stored water are sufficient to “accommodate several successive dry years with negative water budgets,” according to the annual groundwater report available on the district’s website.
From Oct. 1, 2011 through Sept. 30, 2012, San Benito County recorded 6.33 inches of rain fall. The term from Oct. 1-Sept. 30 is used in hydrology to mark the water year. Since Oct. 1, 2012, the county has received 6.08 inches of rain, almost matching last year’s total rainfall in three and half months.
The San Benito County Water District board of directors will host a public hearing regarding the annual groundwater report Monday, at 6 p.m., at 30 Mansfield Road in Hollister.
This year the annual report has been updated, according to district staff, to create “a streamlined report that provides an overview of the basin.” The report includes recommendations on groundwater replenishment, groundwater pumping and the amount of water to import for water year 2013.
In 2012, San Benito received a 40 percent allocation of Central Valley Project water for agricultural use. In addition, the county received a 75 percent allocation of CVP water for municipal and industrial entitlements. The deliveries were similar to 2011. Through storage of unused water from 2011, the district was able to use some of the allotment in 2012.
“Because the district has developed and continues to develop management tools, it has the ability to alleviate some of the variability of CVP allocations,” the report noted in the executive summary. “Given the future uncertainty of CVP water, the District may have to rely increasingly on these tools to provide a consistent water supply to its customers.”
The report notes that updated land uses may also change how much water is needed in the district because 75 percent of demand is for agricultural irrigation. By looking at an aerial map, the report concluded that crop acreages in 2010 had dropped down to the same level as 2002.
“The reduced water use in recent years may be the result of the decreasing agriculture acreage,” the report reads.
District staff said the capacity for groundwater recovery in wetter years “is sufficient to balance moderate increases in groundwater pumping during dry years without causing overdraft.”
Rain totals by water year
2011: 12.58 inches
2012: 6.33 inches
2013: 6.08 inches to date
