Congress is about to try again to help ease California’s drought. A handful of bills — some new, some held over from last year — will come up for debate in the weeks ahead.

The subject is as partisan as the presidential race, and a lot more complicated.

That’s because, when you get politicians involved in water, the debate becomes fixated on righting perceived wrongs, and drifts irrevocably away from solving actual water supply problems.

Such is the case with the present selection of bills before Congress, which come from both ends of the political spectrum. The main contenders are offered by Democratic Sen. Dianne Feinstein, and Republican Rep. David Valadao of Hanford. They have this in common: They have drifted significantly from the basic goal of helping supply more water to Californians into an arena of reversing decades of environmental policy.

Discerning the helpful proposals from the hyperbole can be difficult. So as a guide to the process, Water Deeply offers the following four themes to watch as the bills are debated.

1. Water Delivery

Improving delivery of existing water supplies is an obvious place to start with new legislation. As the thinking goes, there must be inefficiencies in existing mechanisms of water delivery which, if they could be corrected, would result in more water for struggling farms and cities.

If only it were that simple.

California’s water supplies are already stretched so thin — and analyzed repeatedly by some of the world’s best water managers — that there really isn’t any slack to capture and redistribute. In addition, recent studies have confirmed that state officials have handed out diversion rights to five times more water than nature actually produces in “good” weather conditions.

Feinstein’s bill (SB 2533) proposes to deliver more water by ordering federal agencies to heed one simple command: “maximize.” Her bill, introduced Feb. 10, uses that word no fewer than 10 times to order federal agencies to adjust their management of dams and diversions in California to deliver more water.

Valadao’s bill, HR 2898, deploys the same word six times. His bill passed the House last year. It’s considered likely to be paired up with Feinstein’s legislation, if her bill wins Senate approval, in conference committee to produce a final piece of joint legislation.

Among other things, Feinstein’s bill directs federal agencies to open the Delta cross-channel gates “to the maximum extent practicable to … maximize Central Valley Project and State Water Project pumping.”

The gates, located near Walnut Grove in the Sacramento-San Joaquin Delta, are operated by the U.S. Bureau of Reclamation to divert a portion of the Sacramento River’s flow toward diversion pumps near Tracy.

The problem is, the gates historically were operated in just that way. This was found to be devastating to juvenile salmon attempting to migrate to the ocean, because the open gates divert them into the mazelike channels of the interior Delta, where they are more likely to be killed by predators and pollution. In recent years, the gates have been closed during key salmon migration periods, which often coincide with spring snowmelt periods, unfortunately.

In testimony Oct. 8 before the Senate Energy and Natural Resources Committee about an earlier version of Feinstein’s bill, Deputy Interior Secretary Mike O’Connor said, “We strongly disagree with the idea that new legislation will salvage more water than the operators on the ground are wringing from the system every day.”

2. Endangered Species Act

One reason officials can’t “maximize” water deliveries is because the Endangered Species Act requires them to also protect imperiled wildlife. An obvious solution is to simply sweep the ESA out of the way.

That is the path taken by Valadao, whose bill proscribes a number of exemptions to the ESA to increase water diversion from the Delta.

For example, it directs federal agencies to boost diversions 50 percent beyond current limits set in separate biological opinions written to protect endangered delta smelt and winter-run Chinook salmon.

“What does it mean that we might actually wipe delta smelt off the face of the Earth?” asks Doug Obegi, an attorney at the Natural Resources Defense Council. “This legislation might actually accomplish that.”

Even Feinstein proposes adjustments to the ESA, although in more subtle terms. Her bill allows greater Delta diversions than the biological opinions permit – for example, during periods of heavy storm runoff.

Never mind that the biological opinions have been repeatedly vetted by independent scientific reviewers, and a federal appellate court, as being both reasonable and necessary to protect the fish under all weather conditions.

3. New Water Projects

Both the Feinstein and Valadao bills would enact a number of changes in federal law to accelerate construction of new water storage reservoirs in California. This would largely occur by streamlining federal review of these projects.

Valadao’s bill goes the farthest in this regard in order to pursue construction of the proposed Temperance Flat reservoir on the San Joaquin River. Among other things, his bill would require federal agencies to ignore a 2014 report by the U.S. Bureau of Land Management recommending that portions of the San Joaquin River should receive federal protection as a Wild and Scenic River.

Temperance Flat, estimated to cost $2.5 billion, is the poorest performer among a half-dozen proposed new reservoir projects in California. It would have an estimated capacity of about 1.3 million acre-feet (1,600 million cubic meters), but less than 100,000 acre-feet would be considered “new” water yield in an average year. That’s because the rest is already assigned to other users and would be merely parked in the new reservoir until those users demanded delivery.

Feinstein’s bill allocates some $1.3 billion in federal funds to support new storage projects. It would allow some of this money to be spent on raising Shasta Dam to increase its water-holding capacity. This project is bitterly opposed by many environmental groups, in part because it would flood lands along the McCloud River that are sacred to the Winnemem Wintu tribe. It would also violate state law, which protects the river as a wild trout fishery.

The Valadao bill is almost entirely focused on constructing new reservoirs. The Feinstein bill, on the other hand, does support other kinds of water supply, including groundwater storage, seawater desalination and wastewater recycling.

A third bill, HR 2983, is almost entirely focused on these other options. The bill by Rep. Jared Huffman, D-San Rafael, would tap several billion dollars in existing federal funds to support projects including wastewater recycling, desalination, stormwater treatment and groundwater recharge.

Huffman’s bill would also require the U.S. Army Corps of Engineers to immediately undertake pilot projects to operate existing reservoirs under new rules that make use of advanced weather forecasting. Today, most reservoirs are controlled by 50-year-old rulebooks that pay no heed to the weather, resulting in water discharges during flood season even if a flood is not expected. This change could be implemented in short order to save millions of acre-feet of water. Feinstein’s bill includes a similar measure.

Huffman’s bill, introduced in July, has yet to be granted hearings in the Republican-controlled House.

4. Overriding State Law

Federal agencies work in close partnership with their state counterparts. After all, the California Department of Water Resources operates the State Water Project, one of two major water storage and diversion projects in the state. The other is operated by the U.S. Bureau of Reclamation. Together, they coordinate operations to manage water efficiently and avoid harming endangered species.

But in several cases, the drought bills direct federal agencies to ignore state law or, at a minimum, forget about their longstanding partnership with state agencies.

For instance, a portion of Feinstein’s bill directs federal agencies to maximize water extractions from the Stanislaus River, where Reclamation operates New Melones Reservoir. This could result in violating water rights priorities, which are overseen by the state.

Both the Feinstein and Valadao bills contain language that would guarantee certain water supplies to Reclamation’s Sacramento Valley agricultural water buyers. This means these water buyers, who have no actual state-recognized water rights, could end up receiving more water than people who do hold rights, which are superior under state law. In short, it could upend a century of state water rights law.

And all that language about “maximizing” water deliveries would run afoul of the Delta Reform Act. The 2009 state law imposed “co-equal” goals under state policy to both restore the Sacramento-San Joaquin Delta and improve water deliveries. A federal mandate to maximize water extractions from the Delta would necessarily come at a cost to the environment.

“A number of fish species are in serious jeopardy and political intrusions in technical management decisions are not helpful,” Dante Nomellini, an attorney with the Central Delta Water Agency, wrote in a Feb. 24 comment letter on the Feinstein bill. “Beneficial efforts to increase water supplies should be focused on those which reduce reliance on exports from the Delta.”

Matt Weiser is a contributing editor at Water Deeply. He can be reached via Twitter at @matt_weiser.

Top image: A section of the California aqueduct passes through a southern portion of the Central Valley. Recently proposed federal legislation could make changes to how much water is pumped out of the Delta to the Central Valley and Southern California. (Chris Austin)