It now appears San Benito County Water District customers could be on the hook for more than $730,000—or its roughly equivalent in stored water under a proposed deal—in sunk costs for the ill-fated, multibillion-dollar Pacheco Reservoir Expansion Project. … On Oct. 29, the county water district board of directors is set to consider a proposal to cover the district’s share of environmental review costs through December 2021, set at 2.5%, for the $3.2 billion Pacheco expansion, which was dropped by the Santa Clara Valley Water District last month.