Two facts determine water realities in California: (1) The state is out of water, and (2) In order to develop more than 499 units, builders must declare a long-term source of water.

Fact number two is the driving force in what has become a bidding war for the “available” water in a state that every year promises more water than it can deliver.

Since 2001, developers must declare a long-term water source prior to building. Before that, once the houses were up, water had to be delivered. As recently as 2008, courts began ordering dozens of building projects be put on hold until they could find water sources.

The outcome of the need to declare water sources has been more pressure to take  water from agriculture and the environment. The plan to build two huge tunnels to convey water south from the San Joaquin Delta, backed by water districts in southern California and the southern San Joaquin Valley, emphasizes the volume of water the tunnels can carry, with little regard for how much water is needed up north.

Water users in the southern San Joaquin Valley have already ruined enough water and soil to question their demands for ever more water. After draining the aquifer and poisoning the soil with salinity and nitrates, the question now is how much longer it makes sense to send water to unsustainable projects.

Supervisors in Kings County have already made it easier to convert 81,750 acres of farmland to other uses because the land is too contaminated to remain productive. Much of the acreage is in the Williamson Act, but county supervisors have admitted it no longer makes economic sense to try to farm the ruined soil.

But questions about soil and potential uses will be pushed aside as water becomes just another commodity. The big pushers—and big payers—for the tunnels will demand what they paid for, and that will make other uses for water subject to a bidding war the public can’t win.

Ultimately, water will be used to fuel growth simply because that’s where the money is. Those who’ve obtained water rights will sell them to the highest bidders, and the highest bidders in the end will be residential and commercial builders.

In Stanislaus County, which only a few years ago boasted one of the last viable aquifers in the San Joaquin Valley, growers on the County’s east side are draining the water so fast their neighbors’ wells are going dry. Watch for a strategy much like developers once used to provide water for housing.

Promoters of unsustainable agriculture will argue the dire need for water transfers while citing anecdotes about family farmers and the nation’s heritage. They’ll farm until the aquifer is gone and the soil is contaminated, then promote roads and population growth, even if it means diverting water from sustainable agriculture and fisheries.

In some cases, the pressure for population growth will drive water prices higher than the return on crops. This has already happened in southern California. When farmers realize they can make more money with less effort by selling water instead of crops, they sell water.

As housing prices rebound from the Great Recession, watch for a parallel rise in the price of water. And unless Valley citizens remain eternally vigilant, they’ll find their agricultural heritage has been hijacked by the highest bidder.