The state that harnessed the internet is in the Dark Ages when it comes to managing water. A new report suggests steps to harness the data that could make California a better steward of the precious commodity.

One of the shocking truths to emerge from California’s continuing drought is this: the state has no idea how much water it has.

Nor do its leaders have a clear idea how much water is actually diverted by users, what it is used for and how much is left over.

“It’s kind of surprising how little we know about some of these issues,” said Alvar Escriva-Bou, a research fellow at the Public Policy Institute of California. “There is much room for improvement.”

The cause of this ignorance is the state’s antiquated system of water laws. Those who hold water rights are required to report their diversions only every three years. These reports are merely estimates – not based on actual flow measurements – and nothing has to be reported about how the water is used.

It gets worse: those with the most longstanding water rights – established before 1914 and so-called “riparian” rights – don’t have to report at all.

“Our information, in some cases, is three and four years out of date when we are trying to make real-time decisions on how to manage in the teeth of a drought,” said Michael George, Delta watermaster at the State Water Resources Control Board, the agency that oversees the rights. The Delta is California’s largest and most important watershed. “We have a lot of work to do just to get reasonable accounting.”

Accounting for water is a new concept for California that means tracking inflows and withdrawals as carefully as money is managed in a bank account. It is not just a bookkeeping exercise: Precise accounting would help the state to ease the pain of water shortages during drought and prevent environmental disasters.

For example, rather than requiring everyone to meet the same standard conservation target – as state officials did in 2015 – targets could be tailored based on real data about local water supplies. And rather than guess if endangered salmon will have enough water to survive in shrunken streams, the state could deduce exactly what the fish need and ensure water is on hand to flow at the right time.

Doing all that would require sweeping changes to California’s water laws and management systems; it would start with a huge data-gathering and analysis effort.

The PPIC in June published a study that helps outline such an project. Called “Accounting for California’s Water,” it recommends improvements in 13 areas to track water movement, offering examples from other states and nations already using these methods.

“California has one of the world’s most complex [water] systems,” said Escriva-Bou, the study’s lead author. “But once we have said that, we have to acknowledge we are using 20th-century technologies and practices that can’t meet information demands of the 21st century.”

Colorado, for instance, has had a program in place for years that remotely monitors streamflow, water diversions from streams and return flow after diversions – all in real time using a system that is publicly accessible online. California has some of this information available, but it is not easily accessible, not available for all critical streams and water basins, and not integrated across different government agencies.

“I would say the information is there,” said George. “And it is ‘publicly available.’ But it’s hard to know exactly where it is. It’s in different formats. Some of it you have to get at through Public Records Act requests. There’s a lot of data, but it’s hard to find, access, understand and correlate.”

Spain has longstanding programs to jointly manage groundwater and surface water. This is important, because rivers recharge groundwater, and heavy groundwater pumping near creeks and rivers can deplete streamflow. California, on the other hand, does not integrate groundwater and surface water management. Until last September, it was the only western U.S. state that did not regulate groundwater pumping at all.

The Australian state of Victoria has a highly evolved water marketplace that closely tracks sales, trades and transfers online, providing daily updates of transactions and prices. Australia, along with Colorado and Oregon, also assigned water rights to environmental purposes, ensuring fisheries and habitats have guaranteed access rather than relying on leftovers.

California is a long way from any of these programs, but it has made some important strides recently.

In 2014 the state adopted the Sustainable Groundwater Management Act, which will begin to regulate extraction for the first time. Although it has distant compliance deadlines, it may ultimately bring about some integration of groundwater and surface water management, as regulators and water users will be forced to realize they depend on surface water to recharge aquifers.

And in 2015, California adopted Senate Bill 88, which requires anyone who diverts more than 10 acre-feet (12,334 cubic meters) of water per year from a stream to precisely measure and report their water usage – including those holders of old water rights who so far have needed to report nothing.

Starting in 2017, this will eliminate the practice of merely estimating water use. From 2020, all these diverters will be required to report their water diversions in real time using telemetry devices.

The PPIC report acknowledges these steps, but says California needs to do more, including:

Set standards for groundwater accounting, to ensure all new groundwater sustainability agencies are speaking the same language.

Firm up water claims to assess how much is available for trading, and create a platform to make trading information publicly available.

Increase monitoring of water flows in ecologically sensitive streams to set environmental water budgets.

Consolidate information on water availability and environmental indicators across agencies, expand real-time streamflow monitoring and make this information publicly accessible on a unified platform.

Some of these steps are asking a lot of California’s farmers, who hold the vast majority of the large water rights in the state. Installing sophisticated streamflow telemetry devices is costly, and managing the enormous volumes of data they produce is complicated and time-consuming.

Reclamation District 108 in the Sacramento Valley, for instance, has spent $2 million installing streamflow monitors at all its water diversions, to comply with Senate Bill 88.

“It’s extremely expensive and, basically, the farmers end up paying for each one of these,” said Lewis Bair, the district’s general manager. “It’s a huge amount of data when you look at the state. Just for my district, the quality control efforts around that data are enormous. I have staff members doing that full time because there are always changes – things go wrong and they break.”

Yet Bair and his board of directors support these requirements. Among other things, the data will help some of the district’s farmers track their own water usage more precisely, he said, and the new systems make it easier to train new employees in some of the district’s operations.

“They feel very strongly about the fact that they are good stewards of the water, and they don’t want to tarnish that reputation at all,” Bair said of his board.

George supports the PPIC’s recommendations. But he said some will be far more difficult to adopt than they seem at first glance. In 2020, when thousands of automated flow measurement devices begin feeding continuous data on water diversions, the state faces a monumental task to harness it.

“Frankly, the state does not have the capability of managing big data,” George said. “That’s one reason that mandate [in Senate Bill 88] was put off to 2020 so that hopefully, in the interim, we’ll be able to gear up to actually use and manage that data more intelligently.”