California urgently needs more practical, effective ways to improve conditions for struggling populations of native fish and waterbirds. A key ingredient is to add more water to rivers and wetlands at critical times of the year. Water trading is a proven way to do this—it brings necessary flexibility for environmental water managers while also reducing conflicts over the allocation of scarce supplies.
Buying water to support nature is not a novel concept in California. In fact, federal and state agencies helped jumpstart California’s water market during the 1987–92 drought by purchasing water for wildlife refuges and fish hatcheries. Today, environmental water purchases support wildlife refuges, increase flows for fish in the Sacramento–San Joaquin Delta and other watersheds, and reduce salt build-up in the Salton Sea.
Most of the water comes from irrigation supplies. Farmers are paid to release water they have in storage or to change the timing or amount of water they use on their fields. This offsets the farmers’ own costs and gives environmental managers access to water to support habitat priorities. In the early years, most environmental water deals were for a year or less. Starting in the 1990s, multiyear leases—lasting anywhere from 8 to 15 years—became more common.
Although both buyers and sellers have become more comfortable with environmental water trading, the trends suggest waning momentum for this approach. Environmental water purchases peaked in early 2000s, at around 400,000 acre-feet annually. They fell to just half that level during the latest drought. Environmental purchases fell from 30 percent to just 15 percent of all water trades—despite continued market growth.
Instead, the decline reflects a drying up of funding. In today’s dollars, roughly $620 million was spent on environmental water acquisitions from 1984 to 2014. Almost three-quarters of this sum came from state (53%) and federal (20%) taxes—mostly state general obligation bonds that are repaid with general tax revenues. Water users have provided most of the remainder. Notably, 23% is from an ecosystem restoration surcharge on water sold to Central Valley Project (CVP) contractors that is used to acquire water for wildlife refuges and some instream flows. Participants in a large water trade between the Imperial Irrigation District and San Diego are funding mitigation for the Salton Sea.
In the near term, funding constraints are likely to further reduce environmental water purchases. One large multiyear deal funded by past water bonds—a 60,000 acre-feet/year lease to support Delta flows for endangered smelt and salmon—is set to expire later this year, and no funds have been identified to continue the program.
To reverse the trends, California needs to develop more stable approaches for acquiring environmental water. One way is to permanently buy water rights, rather than just leasing them. Proposition 1, passed by voters in late 2014, sets aside $200 million for this purpose. Permanent acquisitions of water rights entail greater up-front costs, but they give environmental managers an asset they can count on.
Another way is to create a stable pool of funds, so that environmental managers can flexibly lease water when and where it’s most needed. Bonds are not the right vehicle for this. Instead, a small surcharge on water use—similar to the CVP ecosystem restoration fund—is what’s needed.
Either way, California needs to unleash the potential of water trading to improve conditions in the state’s rivers and wetlands. Australia, facing similar challenges and conflicts over the use of scarce water supplies, invested several billion dollars to permanently buy back water for the environment. This process has given the environment an equal seat at the table and taken much of the heat out of day-to-day management decisions. As a result, river and wetland species have a much better shot at thriving in a variable, drought-prone climate.