DELTA WATERMASTER REPORT: Complaint alleging unlawful diversion in the Delta triggers investigation; Drought emergency regulation; Voluntary dry-year response program; and Open ET

At the September meeting of the Delta Stewardship Council, Delta Watermaster Michael George updated the council members on the activities of his office.  In his update, he discussed the drought, an investigation into a complaint alleging unlawful water diversion within the Delta, efforts to develop a predictable dry year response to water shortages in the Delta, the risk of the drought continuing into the new water year, and the imminent rollout of Open ET.

Investigation of exporters’ complaint alleging unlawful diversion in the Delta 

A complaint was filed on June 10 by the Friant Water Authority alleging unlawful diversions in the Delta. That complaint was joined fairly quickly after that by additional Delta exporters, including Westlands Water District, the San Luis Delta Mendota Water Authority, and the State Water Contractors.  As a result of that complaint, the Office of the Delta Watermaster and the Division of Water Rights have joined forces to manage the investigation of the complaint; that investigation is ongoing.

I’ll summarize the complaint by saying essentially, it’s a mass balance estimate of depletions of water within the Delta,” said Mr. George. “What I mean by that is the complaint looked at sources of water coming into the Delta, outflow from the Delta and exports from the Delta, and said the difference between the inflows and those outflows are a mass balance estimate of depletions that happen within the Delta. And based on that, they claim that there must be some unlawful diversions within those depletions. So the aim of the complaint is to induce the Office of the Delta Watermaster and the Division of Water Rights to discipline those alleged unlawful diversions to protect releases of previously stored water by the projects.”

Now, it’s important to focus on the fact that the riparian diversions are not curtailed in the Delta,” he continued. “The methodology does not currently support curtailing those riparian rights in the Delta. But there is an allegation embedded in this mass balance analysis that some of the water diverted by riparians is outside their ability to access because it’s not natural flow. It is natural flow augmented by frankly, a hard to quantify amount of previously stored water, and it is that protection of the previously stored water that the complaint pans out.”

These exporters claim injury because of the depletion of storage, but I think it is important to note that they are not demanding that the unlawful diversions be stopped for the purpose of expanding exports. So even these complainants who are export-dependent recognize how serious the water shortage is and recognize that if there are unlawful diversions in the Delta, those unlawful diversions being stopped should go to the protection of the Delta, not to exports from the Delta.”

So the Division of Water Rights and the Delta Watermaster are involving the complainants in the investigatory process, so it is open and transparent.  The first task they are working on is refining the mass balance analysis to better quantify the inflows and the outflows.  

It’s important to recognize that there will always be a range of uncertainty in those estimates, but we need do a better job of quantifying that range of uncertainty to get a better handle on the mass balance analysis,” he said.  “Embedded in that is also to differentiate the sources. How do you determine the difference between previously stored water coming into the Delta that should go to outflow or in-Delta use or export and other water that’s available in the Delta, whether it’s return flows, whether it’s natural flow?

Once the mass balance is refined to as good as possible and within ranges of uncertainty, the next step is to disaggregate the mass balance analysis of depletion and figure out its constituent parts.  This includes unmanaged sources, such as the naturally occurring evaporation from the thousands of acres of open water in the Delta, and the evapotranspiration of riparian and aquatic vegetation, particularly invasive weeds and hyacinth.

The managed portion of water depletion in the Delta is water diverted to support crop evapotranspiration. So next step is to evaluate the alternative supplies that are available to support those crop ETs, the biggest of which is the water supply and water quality contract between the North Delta Water Agency and the Department of Water Resources, which accounts for more than a third of the irrigated acreage in the Delta. Mr. George noted there are other water supply contracts they are looking at to investigate the quantities of potential savings available and how those savings might be applied if indeed they are determined to be unlawful.

Working through that process, with the technical team from the Division of Water Rights, our office, as well as the complainants, we’re getting focused on what the data and information are on which we can make additional determinations,” said Mr. George.  “But as always, that will get us to some pretty thorny embedded legal issues, which we have not yet started to address, so that will be another phase of this investigation.”

Drought emergency regulation

In April of 2021, Governor Newsom issued a drought emergency proclamation, subsequently expanding upon that proclamation in May.  Using the authority granted in that proclamation, the Board subsequently adopted emergency regulations to address drought in the Delta watershed on August 3. The Office of Administrative Law approved the regulations, and they became effective on August 19.

The very next day, the Division of Water Rights issued orders of curtailment and reporting to all water right holders in the Delta watershed, affecting about 17,000 individual water rights and about 8000 individual holders by regular mail.  The Board applied the revised water unavailability methodology developed by the Division of Water Rights, which builds on what was used in the last drought with improved data inputs and the ability to visualize the difference between water supply and demand throughout the Delta watershed.

It’s a significant improvement in the data management and methodology that supports the board and the Division’s action with respect to managing in a drought where there is more demand than there is supply in the system,” said Mr. George.

All water right holders and claimants are required under the order to certify their compliance and to sign up for electronic notifications going forward or agree to frequently review the website where the updates are posted.

All licenses with authority to divert and use water within the Delta watershed granted after the Water Commission came into existence in 1914 have been curtailed to preserve water for more senior water rights holders.

In addition, within the Delta, Byron-Bethany Irrigation District and Banta Carbona Irrigation District had their pre-1914 water rights curtailed; their water rights were perfected prior to 1914 and are junior enough to be curtailed and are not supported by any other water right, such as a riparian right or a supply contract.  

Mr. George said he worked with the two irrigation districts ahead of time, so they were prepared for the August 20 order.  Both entities immediately complied with that order because they planned for it.  The curtailment lasted only 11 days because applying the methodology only made curtailments necessary for August; those were lifted by September.  And it’s the end of the irrigation season in any case.

The important part of that is they complied, and they received information on an electronic basis for the regular updates,” he said. “Although they disagree with and have challenged the Board’s authority, they complied. They’re working with us to try and recognize that aside from the regulatory issue of curtailments, the real issue here is physical lack of water because of the drought.”

Riparian rights in the Delta have not been curtailed because the methodology doesn’t support a curtailment finding at this time, he said.

As you would expect, challenges have ensued,” Mr. George said. “The Water Board has been petitioned to reconsider the adoption of the regulations and to reconsider the orders that were issued under it.  In addition, challenges have been filed directly with the courts asking the court to intervene in what complainants have indicated they believe is an excess of exercise of authority by the Water Board.”


Voluntary dry-year response program

Based on dry conditions early in this year, the boards of the North, Central, and South Delta Water Agencies directed their staffs to work together to develop a Dry Year Response Program and asked the Office of the Delta Watermaster to convene the group for the planning exercise. So since February, they have been meeting regularly with the general managers or designated representatives of each of the three water agencies and a small group of their trusted advisors to develop a Dry Year Response Program. 

Mr. George acknowledged that although drought becomes an emergency, it is a predictable event and is better managed through a predictable management program than an ad hoc emergency response.  

With drought planning, you get predictability, but with emergency response, you have to suffer through a great deal of uncertainty,” he said.  “So that was the objective of these discussions.”

The participants have kept their respective boards apprised of the progress being made, thus maintaining their support for the process.  The resulting program aims to present a unified voice for the Delta while acknowledging regional differences and recognizes the opportunities for responding to future drought conditions must be voluntary at the water user level because the Delta water agencies do not own the water rights; their constituents do.

The three components that have come out of this process are:

  • A suite of potential water conservation actions that are different in different parts of the Delta to recognize these regional differences
  • To recognize that within the Delta, water shortage or drought is not experienced as physical water shortage, but rather as a risk to water quality, so what can be done to protect water quality and to avoid salinity intrusion
  • Improvements in data so that as alternatives are being considered, everyone is working from a better, more coherent, shared data set.

Mr. George said the group is developing a pilot for the coming water year since there is a significant risk of continued drought in 2022 and reservoir storage is severely depleted.

In fact, we will go into the new water year next week with dangerously depleted storage that threatens the delicate balance between demands on our water supply and the extreme variability of that supply and the inherent threats to both ecosystem function and water supply uses or demands on the Delta,” said Mr. George.  “Because of the reduced supply in the rim reservoirs, the risk is that there may not be sufficient freshwater net outflow to hold Bay salinity out in the bay and increasing the risk of intrusion of salt into the interior Delta.”

As a result of this risk, I have informally started to think about this mantra in the Delta:  Pray for rain, plan for drought, but be prepared for floods; do what we can to reverse the subsidence that increases those risks. Restore the ecosystem as we can so that it can function better through dry periods. Always tend to the levees because, without the levees, we lose control of the system. Beware of climate change, which threatens all of this to go on steroids. And finally, to protect the water rights, not only in the Delta and in the Delta watershed, but the water rights that serve all of California, its people, its ecosystem, its economy, the sociology, all of those things that are critical and central in the Delta.”

Open ET

Open ET is getting close to being launched.  Folks in the Delta have been part of the beta testing process for months.   Once Open ET is publicly available, it will be used for the Delta Alternative Compliance Plan for measuring diversions in the Delta.  It will also provide for the first time a georeferenced connection between points of diversion.

We know where the points of diversion are, but we don’t have the connection between them and a georeferenced place of use,” said Mr. George.  “That’s partly because some of these places of use were determined as early as the middle to the end of the 19th century, so we didn’t have GIS mapping, we didn’t have computer digitizing and georeferencing capabilities. We’re getting that for the first time through the Delta Alternative Compliance Plan; all water users in the Delta who want to take advantage of the Delta Alternative Compliance Plan will come as participants with a GIS indication of their place of use. So we’ll have the user saying, ‘that’s my point of diversion, and this is the place of use which is served.’ That’s going to allow us to gain a great deal more insight.”

The launch of Open ET will provide consistent, credible, and transparent data and timely insight on actual water use in the Delta that will be important for management and regulatory decisions. Coinciding with the release of Open ET will be the release of the Delta Alternative Compliance Plan, which will be in effect for the new water year that began October 1.   The first reports of water use under the new system will be due in February of 2023.

The legislature recently passed SB 155, which consolidated all water use reporting in the Delta and statewide to use a consistent water year.  Since the reporting will be consolidated to the water year, all the reports will be due on February 1 of the following year, which is much earlier than before.

This will provide much more accurate and consistent data, allowing for much more collaboration among different modeling efforts and different reporting efforts,” said Mr. George.  “So this really is a big breakthrough, a big leapfrog. And the high point on which I want to end a miserable water year in 2021 with hope for improvements in the water year that we’re about to enter into.”

Discussion period

Councilmember Maria Mehranian asked Mr. George to expand on how subsidence might be able to be reversed.

Mr. George:You and the other council members are well aware that the highly organic soils in the central part of the Delta are subject to subsidence not in the way that subsidence happens in Central Valley from over-pumping of groundwater; rather, it is through oxidation of those organic soils. So one of the ways to reverse subsidence which has been the subject of a lot of pilot testing and so forth is to deprive that organic soil of the oxygen necessary to oxidize the soils by keeping it saturated at all times.

So there are two major ways that are emerging to do that.  The first is that the Department of Water Resources has a large multi-year project on Twitchell Island, demonstrating that by keeping the soil saturated, you can regenerate essentially tules, which was the natural circumstance in the Delta before reclamation—and stopping the subsidence through depriving those organic soils of the oxygen necessary for the oxidation of the soils.  And with the natural decomposition of the annual crop of tules, you can actually stop subsidence and begin to rebuild it. Now that’s a long-term process, and it’s not possible throughout the Delta. So that’s one promising way of reducing subsidence and thereby reduce the impact or the pressure on our Delta levees. Because obviously, the subsidence behind those levees lowers the land level, you increase the hydraulic pressure on the outside of the levee.”

The second way is to grow a different crop, primarily rice. And so, there is an effort now to increase the irrigated acreage in the Delta devoted to rice. Because again, you flood the area, you deprive that organic soil of oxygen.

It’s important to note that these efforts to reverse subsidence are a trade-off with reducing water use, because both managed wetlands, growing tules or other things, or increasing riparian habitat, or cultivating rice wherein prior years, maybe you grew corn or tomatoes, actually increases overall water use, particularly in the short term. So how you proceed on these two issues of reversing subsidence and managing drought are in tension, which we have to manage. So that’s why reversing subsidence is among the mantra issues.”

Councilmember Daniel Zingali noted that Mr. George had said that the water exporters alleging the illegal diversions are not asking that those illegal diversions be added to exports but be applied to protection.  How much of a departure is that? How much optimism can we take from that in terms of a broader understanding that we’re all in this together?

Mr. George: “This particular complaint is not aimed at increasing exports this year, during the period of time that the complaint has been outstanding.  The complaint was filed in June at the beginning of the irrigation season. At that point, the Friant Water Authority and the other exporters recognized that because of the extreme drought, reducing diversions in the Delta was not going to result in the ability to export more water. Still, it would protect water in storage from needing to be released to meet those alleged unlawful diversions.

I don’t want to suggest that everybody’s singing Kum-ba-yah here because this is water rights in California. It’s never Kum-ba-yah; it’s always a contest because there is a certain amount of water, and there is a priority system for allocating that water in times of shortage.  So I would not say that the exporters in their complaint are foreswearing reducing unlawful diversions that are alleged in the Delta so that in future periods, they could be the beneficiaries of increased exports. I think it is, however, a recognition by everybody that, unlike how we came out of the 2015 drought, where there was a lot of grousing, frankly, about the regulatory drought, nobody is focusing on what’s actually happening in the system.  It misses the point that regardless of the regulatory environment, the physical environment is such that there may not be enough water in storage if 2022 is a dry water year to maintain a sufficient net freshwater outflow to hold salinity at bay. And the risk to the Delta is of salt intrusion, which would interfere with everything that we rely upon in a functioning freshwater estuary. So it is the recognition of the extreme risks that we face because our reservoirs are so depleted; if there’s not a wet year in 2022, the risk is there’s just not enough water in the system to repel salt, and that we could lose the functioning freshwater estuary through salinity intrusion. So it is that wolf at the door that has united everybody in recognizing that protecting as much storage as we can going into an uncertain year is that unifying factor.”

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