The Santa Clara Valley Water District board of directors voted Tuesday to impose rationing measures on the county's 1.7 million residents.
Board members will determine the specifics of the restrictions at its March 24 meeting. At that time, the district will have more information, including updated rainfall measurements and water allocations from the federal Bureau of Reclamation.
"Unless a miracle happens, we're going to go to mandatory rationing at some point," said Sig Sanchez, chairman of the seven-person board.
The board's vote went against recommendations from staff and area water companies. Many individuals present at this morning's meeting wanted to wait until March to determine whether restrictions were necessary at all.
Keith Whitman, deputy operating officer of the district, said that if February and March see average rainfall levels, the restrictions could be unnecessary.
"Historically we have seen some very wet months and some very dry months," he said.
Representatives from several of the county's eight water retailers also noted the cost of implementing water restrictions, and the risk of losing credibility with the public if a plan is announced and then canceled at the last minute.
Whitman said restrictions will likely call for water use reductions between 10 and 20 percent, depending on precipitation. The valley has seen three excessively dry years in a row, causing a shortage in the county's supply of surface water.
Until now, the district has asked water providers within the county for a voluntary 10 percent reduction in water use. However, the average right now is closer to 6 percent, according to board member Rosemary Kamei.
Tuesday's decision puts local municipalities and water companies in a challenging spot, as they must prepare for upcoming restrictions without being able to tell their customers when these will begin, or how they will be structured.
In many cases, restrictions must be enacted by a vote from local city councils, and water companies must inform customers and change their billing practices to impose higher rates on customers who go above their allotted water usage.
Once details are finalized at the March meeting, Whitman said, water providers will need between six weeks and three months to make the water restrictions a reality.