MEETING: Delta Watermaster breaks down water use in the Delta, addresses implementation of reduced reliance on the Delta

At the October 22nd meeting of the Delta Stewardship Council, Delta Watermaster Michael George gave a detailed presentation on estimating water use in the Delta, something he acknowledged doesn’t matter much when there’s plenty of water in the system, but in times of drought, it becomes very important.  He also discussed the implementation of the state’s policy of reducing reliance on the Delta and provided updates on the preparations for the next drought, progress on the alternative compliance plan for implementing SB-88 Delta measurement reporting, and efforts to addressing ongoing deterioration in the south Delta.


Estimating actual water use within the Delta – how much water is actually used and what it is used for, has become much more important to our thinking about the Delta and our managing the Delta in the face of current challenges and challenges that are over the horizon,” said Michael George.

Estimating water use of crops and vegetation

Crop evapotranspiration The actual consumptive use of the crop, and the evaporation of the water that’s needed to make that transpiration water available to help the crop grow.  For example, a process tomato field requires water that the plants then evaporate and transpire in order to grow. 

Riparian vegetation: There is the evapotranspiration of riparian vegetation of which there’s a lot in the Delta.  Mr. George noted that because the satellite can only see the canopy level, it cannot see the many other plants in the riparian areas that are also transpiring water at the same time, so it is difficult to measure.

Particularly as we look forward to having more riparian habitat as we reconnect floodplains and so forth, we’re going to have to take account of that ET of that riparian vegetation,” he said.

Evaporation from open water:  There are a lot of open channels in the Delta, and from those channels, there is unavoidable evaporation that is probably beneficial at some point, he said. 

Evapotranspiration of invasive aquatic weeds: The picture on the lower right hand side of the above slide shows a channel choked with hyacinth, a floating aquatic weed that is prevalent in the Delta.  Most of the bulk of the plant is below the surface of the water; the plants are filtering the water and feeding it up to the top where it evapotranspirates out into the atmosphere.

The scientific work on this is still preliminary, but on a preliminary basis, it appears that the hyacinth actually creates a wick up into the atmosphere that evaporates and transpires water about six times the level of the open water,” said Mr. George.  “In general, when there’s lots of water in the system, most of this means a lot less.  The reason we focus on it is that we’re looking at what happens when water becomes very acute.”

The largest managed water use in the Delta is for crop ET during the growing season; the second largest is the combination of riparian vegetation ET and open water evaporation.  The fastest growing and the most concerning is the wicking action of the floating aquatic vegetation and the loss of water in the system during acute periods, he said. 

Particularly the filtering of that water so that what’s evaporating is the purest freshest water in the system, because the hyacinth is actually a giant filtering mechanism so that is most disturbing and growing most rapidly.  Those aquatic weeds have lots of other problems associated with them, reducing dissolved oxygen, reducing fish passage, and lots of other reasons why we want to get rid of them.”

Estimating non-crop water use in the Delta

Domestic water use: Much of the interior Delta supply for domestic use is from groundwater.  Stockton withdraws water from the Delta, treats it, and serves it to its customers within the city.

Salt leaching:  In the summertime, Mr. George said that the Delta can be a salt sink as it can acquire a lot of salt that flows in and through the Delta, either from saltwater intrusion or from the recirculation of salts that accrue to the system through irrigation primarily from the San Joaquin Valley.

In the offseason, that salt gets leached often through rainfall or high winter flows, but sometimes when we have dry winters, farmers will capture freshwater from the channels and use it to leach the salt out of their system,” said Mr. George.  “That’s hard to measure and manage until we develop a system for doing that that involves the cooperation of farmers in the Delta who are carrying on these activities.”

Ecosystem uses:  In the non-growing season, there are certain ecosystem functions that increase their demand.  For example, farmers in the Sacramento Valley are taking water off the mainstem of the Sacramento River and using it to flood their rice fields, decompose the rice, and also create habitat for migratory birds on the Pacific Flyway.  There are also duck clubs that flood wetlands for hunting.

Gain from and loss to groundwater:  Mr. George acknowledged that it’s impossible to measure, but in general during dry periods, there may be water leaving the Delta channels to replenish groundwater supply and at other times, there is groundwater that replenishes the surface supply.  He noted this is most observable in the Delta islands that are significantly subsided and where the growing field is below the water table.

We don’t have to account for operable storage – yet

Currently, Mr. George said that we don’t have to worry about accounting for operable storage in the Delta – that is, taking water out of the system at one time to use it on a deferred basis in the Delta at another time. 

Clearly we have exports from the Delta and we have withdrawals from the Delta that go to storage, but that storage currently is used for demands that are outside, on the fringes, away from the Delta itself, so when we think about measuring and understanding water use in the Delta, at this point, we don’t need to worry about reservoir storage as an impact,” he said.  “In the future, we may.  For instance, if we see some of the expansion of groundwater and surface water storage projects, it is possible that to the extent that there is shortage in the Delta, people will take advantage of the opportunity to withdraw when their water rights are in priority, put it into storage so as to be able to return it for their use in the Delta.  That is another reason why it’s important now to get a better handle on what actual Delta water use is, because we don’t have to take this into account now but we may at a point in the future.

Acquisition of water supply in the Delta

Mr. George then turned to how that water supply is made available for in-Delta water uses.

Active diversion is the appropriation of the surface water supply. The picture on the slide shows a siphon on Staten Island which is a typical in-Delta diversion structure.  When the water level in the channel on the left side is higher than the growing field on the interior part of the island, the water will flow by gravity from the higher water level outside to the interior growing level.

Crop ET is a portion of that, and a portion runs off ad drainage water. 

Throughout the Delta, tailwater is captured and reused.  While typically tailwater is destined to be pumped off the island back into the surrounding channel, as it’s working its’ way down the system, it is often recaptured and used for irrigation. 

So when you’re thinking about crop ET on Staten Island, there is equipment on the waterside of the levee there is powering a meter to measure the amount of water that’s coming through that diversion structure on to the growing field, but that water accounts for not just one time through but captures the tailwater and reapplication,” he explained.  “So farm water management is an important part of understanding how water supply is actually used in the Delta.”

There is passive diversion or seepage.  There are places where water will seep through the levee, through the rip rap, and into the interior Delta.  This seepage is difficult to measure accurately; it’s just happening all the time, he said. 

You can get a bit of a handle on it by comparing water in through the diversion with water out through the drain pumps, so there are places where we’re working on that with the cooperation of farmers in the Delta, particularly on large islands that are held in single ownership.”

Precipitation doesn’t make such a difference in the dry summers, but can affect leaching and soil moisture content, he noted.

The basis for water diversions in the Delta

Mr. George then turned to the water rights that support the diversions in the Delta.

For a variety of reasons, riparian claims within the Delta have come to be the dominant basis for lawful diversion of water for crop ET,” he said.  “There is also a smattering of pre-1914 claims that were grandfathered into our water management system in 1914 when the Water Commission was set up; the legislature said if you perfected a priority application of water supplies, it’s outside the administration system.  After 1914, the Water Commission, the predecessor of the State Water Resources Control Board, began to grant licenses for water diversion and use within the Delta.  Then there are miscellaneous claims, such as claims to salvage water, claims to overlying groundwater rights, and other unspecified statutory and some specious claims.  In any case, all these are claimed one place or another, one time or another, as the basis for making diversions primarily for crop ET.

Mr. George reiterated that all of this may not matter much when there is plenty of water in the system, but in times of shortage, it all matters and it all matters very much, so this is part of planning for the next drought or shortage.

Applying the Tanaka Decision

Since the last drought, the Third District Court of Appeals has issued their final decision at the appellate level in the Tanaka case.  The case had been 10 years in the litigation process.  In August, the Supreme Court refused to review the case and so that made the Third District Court of Appeals decision the final unappealable published precedential decision.

This was very helpful in my role administering water rights in the Delta, because it is a fresh look at what are the principles behind supporting a claim for riparian water rights,” Mr. George said.  “We are currently involved in private confidential negotiations to settle a number of enforcement actions based on applying the principles enunciated by the Tanaka case.  We announced the first of those settlements last Friday. I’m hopeful we’ll be able to announce another one tomorrow, and we’re hoping that there are several more that we can settle without going to hearing by applying the principles of the Tanaka decision to the individual facts of these enforcement cases.”

While we do that and recognize that riparian rights are the dominant rights in the Delta, we’re also looking at applying where we can the principles in our overlap memo,” said Mr. George.  “Those principles generally stand for the proposition that if you have an adequate riparian supply, adequate to meet all beneficial needs on your property, you don’t have a basis for claiming an alternative or overlapping or additional pre-1914 water right, so we’re getting a better handle on the basis for the diversions.”

Moving to the next phase of the duplicate reporting project

Mr. George next discussed the QA/QC of the water use information that is reported to the State Water Board.  In the first phase, they identified and developed a first stage problem statement with help from colleagues and constituents in the Delta.  They are now moving to phase 2 where they will develop an agreed-upon way of avoiding overlap and duplicate reporting so that the Board can get a more accurate accounting of water use.

He explained that in the past, water for the same purpose and often drawn through the same point of diversion is accounted for in two different places: first in the report of the licensee for the license that may provide a basis of diverting water onto a whole island, and then again in July, when individual landowners and individual water rights claimants report the same water in their diversion & use statements.

We’re trying to squeeze that duplicate reporting out of the system to give us a better sense of what actual water demand in the Delta is,” he said.

The challenge of riparian and appropriative water rights in the Delta

In the end, as Delta Watermaster responsible for administering water rights in the Delta, I have to live with the inherent inconsistencies in the shortage allocation systems that the legislature has given us.  On the one hand, you have the riparian system that came to us when California became a state and the early legislature adopted the common law of England which includes the law of riparianism, and at a later point, primarily in response to the priority demands of the upstream miners, we got an overlay on the riparian system of a priority allocation system.  And that’s first in time, first in right.

These two systems which are overlain on each other are now coming into conflict in times of shortage, particularly in the Delta, where you’ve got both appropriative claim under licenses and some pre-1914 claims and riparian claims,” he continued.  “They share a shortage on a different basis – the riparians on a correlative basis and the appropriative rights in order of their priority.  So what we have is a system that allocates shortage in the same geographic area from the same watershed in two different fashions that are incompatible.”

Take-aways of actual in-Delta water use

Prevalence of riparian rights.  “Particularly in light of Tenaka and in light of the unique history of the Delta, it is riparian rights that are the most prevalent rights.”

The difficulty of distinguishing natural flows in the Delta.  “Riparians have the ability under common law to withdraw only certain kinds of water, specifically the natural flows in the watercourse to which their property is adjacent.  However, in the Delta, there’s a lot of different kinds of water mixing – there’s natural flow, there’s previously stored water that has been released for a specific use which riparians don’t under common law have a right to, and there are return flows from prior appropriations that riparians don’t have a right to.  Yet in the Delta, a riparian stands on his or her levee and looks down and sees water, there’s no good way to differentiate among them.”

There’s case law in the state of California that suggests if you comingle water, you have to deal with the consequences, so to the extent that there is water comingled in these channels to which a riparian does not have a common law right, it may be that there is no way to enforce against a riparian who in good faith takes water out of the channel because an enforcer like the Delta Watermaster cannot differentiate and say you took some water to which you were not entitled.”

Apparent over-reporting of actual water use.  “Besides the duplicate reporting, there are those who have been reporting high estimates for the fear of a day when all water rights would be cut back on a percentage basis, so they reported a high amount of water use so that they could justify the amount they needed in the case of a cutback.  We’ve seen precisely that judicial response in adjudications of groundwater basins, so it’s not a silly or unfounded concern.  But the result of that is that we have significant overreporting of actual water use which we’re now trying to get down to.” 

The challenge of administering in times of shortage curtailment,particularly because of the overreporting of water use in the past and because of the duplicate reporting and because of the inconsistency of the shortage allocation system.”

There is actually less variability of water use in the Delta than has been estimated and modeled.  “We thought there was more variability between wet years and dry years, and there’s a lower volume that we formerly estimated.  That has real world consequences because those estimates find their way into models.  We use the models to manage within the system, so this is an important effort and that’s why I wanted to take a deep dive in talking to you about the intricacies of identifying and getting a consistent set of data that are widely respected and agreed to be credible so that we can begin to move off of arguments about what’s happening and get into the discussion what should we do about it.” 


Next, Mr. George took a deep dive into the state policy of reduced reliance on water supply from the Delta, beginning with the words written in statute in Water Code Section 85021: 

“It is the policy of the state of California to reduce reliance on the Delta in meeting California’s future water supply needs through a statewide strategy of investing in improved regional supplies, conservation, and water use efficiency.  Each region that depends on water from the Delta watershed shall improve its regional self-reliance for water through investment in water use efficiency, water recycling, advanced water technologies, local and regional water supply projects, and improved regional coordination of local and regional water supply efforts.”

It’s a very clear, very straightforward state policy, but as with many things, it’s harder when you start to think about how it gets actually implemented, he said.  One thing that has to be taken into account is the extensive variability and volatility of the Delta water supply and the head-snapping juxtapositions of drought and flood.  One concept that has emerged in terms of managing with the Delta is called the ‘big gulp, little sip’ strategy, which proposes to take water out when there is a lot of water in the system (big gulp) and storing it so during dry times, less water is diverted (little sip). 

That’s an overall strategy that we’ve talked about in the Delta to deal with this variability and volatility which we recognize is likely to increase as the result of climate change,” said Mr. George.  “But in applying this strategy for managing the highly variable and volatile system, we need to take account of the different challenges faced by urban and ag users in dealing with that extreme variability of supply.”

He then listed four:

Volumetric affordability: Affordability on an acre-foot basis is obviously higher for urban users than ag users. 

Immediacy and recurrence of need:  With many growers migrating to permanent crops, there is a hardened demand because permanent crops cannot be fallowed.  So that demand is hardened and it occurs precisely during the warm summer months when shortages are likely to be most acute.

Infrastructure rehabilitation and expansion:  Both ag and urban users are facing real problems with deferred maintenance and loss of functionality in infrastructure across the board, Mr. George noted. 

Available revenue streams: Urban water users are in a far better position to organize themselves as they have with respect to reduced reliance to increase their stormwater capture, to increase south of Delta storage, and thinking of things like Diamond Valley Reservoir. They are increasing their use of groundwater storage, becoming involved in asymmetric water trades with agricultural water users particularly in the San Joaquin Valley, desalination, significant programs for conservation, and reduced demand.  All of those things are differentially available or affordable on the urban system compared to the ag side, and that relates directly to the differential availability of revenue streams to support it.”

Improving Management, Avoiding Cost, or Chasing the Chimera?

So what are the implications of that?  “People are looking at the Delta and trying to figure out what reduced reliance means to them, and I categorize these as how can we improve the management of what we have or improve how we use the Delta for all these various uses,’ said Mr. George.  “There’s also a lot of work on how do we avoid the costs associated with improved management or reduced reliance, and then what are the temptations for what I call ‘chasing the chimera’ of squeezing more water out of the Delta for use somewhere else.”

He pointed out that there have been a number of recent cases and contexts where the straightforward policy of reduced reliance has come into actual focus and implementation:

Real-time project operations.  “One is in how we migrate to the improved real-time management of operating the systems we already have – better SCADA systems, better real-time analysis of what’s going on in the ecosystem, improved measurement of diversion and use throughout the entire watershed and the export community that relies on it,” he said.  “Some of that has been contentious.  Think about the lawsuits that are going on over the new biological opinions or the incidental take permit.  Those regulatory efforts to constrain and manage so as to avoid damage … in all the operations where we try and manage water supplies within the watershed, so there’s good creative stuff that’s going on there, but some conflict about how that change in project operations is going to affect the system.”

Delta conveyance:  “We’re also involved in consideration of alternative conveyance, which the Delta Plan has endorsed in concept, and now we have the Design and Construction Authority trying to figure out what the best way to accomplish that objective is.  Again, highly controversial and undoubtedly subject to a lot of pushback and almost inevitable litigation.”

San Joaquin Valley Blueprint:  Mr. George said he is a big supporter of the San Joaquin Valley Blueprint, which is an effort to bring together all the water users in the San Joaquin Valley to address the effects of SGMA implementation and make up for the deficit of 2.5 MAF per year.  “As they think within this broad-based blueprint about what they can do to come to grips with that reduction of 2.5 MAF on average over time, they are looking at a lot of San Joaquin Valley infrastructure improvements, getting greater supply reliability through groundwater storage, replenishing those overtaxed groundwater basins, finding the right places to do that, and lots of stuff that are the no regrets activities that the San Joaquin Valley would like to do to put itself in a better position to deal with the reduction of groundwater that’s going to come through SGMA implementation.”

However, in addition to that, they are naturally looking at what they can do to augment the supply and it’s not unusual that they should look to the Delta and figure out are there water supplies there that can be successfully wrung out of the Delta and used to augment San Joaquin Valley supply,” he continued.  “I’ve been pretty vocal in saying that I think that is ‘chasing a chimera’ by and large because even if you look at the times at which there’s a lot of supply in the Delta, we don’t have the infrastructure to capture it at those brief and unpredictable periods of time.  And the cost of that infrastructure, even if it could be permitted and even if the funds could be raised to support it and maintain it, it would be used only a few days per year and not in every year because those big flows that make up the average of water “lost” from the Delta come in very short periods.  So I’ve tried to weigh in with the blueprint to suggest that they need to be careful about putting much planning into getting a significant increment of water from the Delta.”

San Diego County de-annexation: Two member agencies of the SDCWA have proposed to their local LAFCO to withdraw from the San Diego County Water Authority so as to take water under contract from a different Met member agency.  “I weighed in on that to tell LAFCO, the SDCWA, and the deannexing agencies, and the alternative Met water supplier that they all need to take a look at that section of the state water code about reduced reliance.  What we wouldn’t want to have happen is for areas where there is a significant investment in the very kinds of regional reliance and reduced reliance on the Delta, which is expensive, like desalination of some of these other projects for harvesting wastewater and turning it into tap water – those are expensive.  And we need to take into account, and the users and LAFCO and others should think about, even though they are hundreds of miles from the Delta, whether their actions are in concert with the state policy of reduced reliance.”

Orange County planning.  “The Metropolitan Water District of Orange County was gracious enough to invite me recently to speak to their membership in a virtual forum about what they should know about what’s going on the Delta,” Mr. George said.  “Orange County is one of the leaders in these very intelligent asymmetric water transfer transactions which are multi-year transactions an agency in Orange County will agree with an ag agency in the San Joaquin Valley, in which when there is lots of water, we’ll give you the water this year, say 100 acre-feet for example, and we’ll expect to get back from you in a future year 50 acre-feet, or half of that.  That’s what I mean by an asymmetric trade and they do it so as to manage this volatility in the availability of supply.”

But one of the things that I mentioned to them in the forum was that you need to be careful about thinking about those asymmetric transactions because of how the demand in the Central Valley relates to the urban demand, so these are all contexts in which people are struggling with exactly how they apply this relatively simple straightforward requirement for reduced reliance.”

Takeaways on reduced reliance

Measuring by rate, volume, or time?  We need to figure out what reduced reliance means, he said.  “Is it how many CFS are taking out at a moment?  Is that what we’re trying to reduce?  Or is it overall volume?  Do we allow for that variability of rate?  Take a lot when there’s a lot of water, take a little when there’s not much water, but the volume is about the same?  Are we looking at a time, and are we only caring about that increased reliance in times of shortage or in times when we can predict or expect to have a shortage?” 

Evaluating methods for capturing ‘excess’ supply:  “We need to evaluate what are the methods for capturing that ‘excess supply’.”

Enforcing through a ‘consistency determination’:  In terms of the Delta Plan, the enforcement of the reduced reliance through the consistency determination process gets at that problem, except where whatever is the issue is not a covered action.  “Go back to that San Diego issue I referred to earlier.  The deannexation of those two agencies from San Diego and their annexation or contracting with another Met member agency is not a covered action because it doesn’t take place in the Delta.  But does it imply an increased reliance on the Delta supply because those two agencies will reduce their diversity of supply available through the San Diego County Water Authority, in favor of a less diverse supply that at the margin, and that probably means more Delta water going to that use.  It kind of doesn’t matter whether it’s even the same molecules of water, because if more of their mix is from the Delta, that means that certain other demands can’t be achieved from that Delta supply.”

With adapting to climate change, it’s not likely to come gradually, but more likely to be a black swan event – one that is predictable at some point but is always a surprise when it shows up, such as an earthquake, a levee failure, a flood, a storm surge with a King tide.  “It’s the confluence of events that impacts or overwhelms us, so as we think about our traditional process of planning for the next drought or planning for the next shortage condition, we really need to be thinking about climate change in both of these areas, the gradual increment of sea level, the change in our precipitation patterns, the volatility, but also these black swan events.”


Presenting credible and accessible data:  Capturing, presenting, and using credible and accessible data is important to inform the operational flexibility that is needed. 

We clearly need to use our infrastructure better, more intensively, but more wisely based on what we’re monitoring, what we understand, and shared understanding of what the data are, so that’s why we’re spending so much time within the office of the Delta Watermaster focusing on these issues,” said Mr. George.  “That’s how we’re going to be able to appropriately manage risks in the future.  Importantly in managing those risks, we have to make tradeoffs.  We all know that there are tradeoffs in almost all the Delta management decisions we make, and because there are tradeoffs, we’ve got constituents on either side prepared to fund their lawyers to take us into court and fight us, whoever us is.”

“So having better data and having people understand that data and use that data should help us to argue more about how we should implement what we learn from the data and spend less time arguing about what the data tell us.  That has the potential at least to reduce the friction in every decision we make, that friction of litigation, of permitting, etc, that constipates us in taking actions that could actually have some adaptive management benefit for the Delta.”

Finally, we have to do this all in the context where we’re facing the dual challenges with the frog in the pot and the black swan event presented by climate change.”

Public comment

During the public comment section, Osha Meserve with Local Agencies of the North Delta noted that with respect to aquatic weeds, they do get flushed out by higher flows.  “So certainly in the Council’s thinking around this issue which is identified as an action item in the water resilience portfolio report under 12.2 to manage invasive weeds, certainly I think flows are one of the things among others that need to be addressed to try to address weeds.   In addition, I throw harmful algal blooms under this weed heading as well as flows are one of the best ways to minimize algal blooms as well.”

Ms. Meserve also pointed out that with respect to groundwater and surface water interactions in the Delta, if river levels are lowered from large diversions on the Sacramento River, that also reduces groundwater recharge to the South American subbasin as well as the Eastern San Joaquin subbasin, which extensive evidence was presented about this problem in the Water Fix water rights hearings a couple of years ago. 

Integration with SGMA is going to require taking a look at these issues about how large diversions could also impact our ability to reach sustainability, for instance, in the South American subbasin which is in the process of preparing it’s GSP, because the Sacramento River is a losing reach in that area and actually helps recharge the subbasin, and so this is yet another driver for implementing that policy of reduced reliance.”

With respect to overlapping water rights in the Delta, Ms. Meserve noted that from her perspective, Delta water users don’t agree with the theory that there cannot be overlapping rights.  “That’s an ongoing discussion that lawyers and others are having about what the water rights system of California allows and what’s appropriate.  Certainly, all the water users know that we should not be double reporting and we cannot be double using and Delta water users don’t have anywhere to put water they can’t use.  Of course, everyone is subject to reasonable use.  So I hope to make progress on that discussion and come to a good place with the Watermaster on how to make sure that the databases are accurate and helpful but at the same time, not undermine the senior water rights that come in a few different forms for Delta water users.”

Lastly, with the San Joaquin Valley Blueprint, Delta stakeholders are not part of that process and have not been invited to participate.  “I would say, I do have a large concern about the Blueprint seems to intend to make up a 2.5 MAF overdraft in the South San Joaquin Valley with increased water deliveries from the Delta potentially … they do indicate that their interest in the idea of exporting an additional 2.2 MAF per year by making more aggressive exports from the Delta, so I just want to flag for the Council and others that there is controversy around the approach and the Blueprint.  … To the extent that the Blueprint robs Peter to pay Paul in terms of taking freshwater out of the Delta to try and make up for a problem with groundwater recharge, I don’t think that is sustainable and that’s probably something that will have to get worked out in the SGMA implementation years … “


Preparing for the next drought

Last year was a relatively dry year and the state is headed into the next year with warmer temperatures and lower reservoir storage, they are preparing for next year in case it’s a drought.  Since the last drought, they have been working on improving data analytics, data accessibility, and the transparency of the information, much of which is reported by water users.  They are working to do a better job of QA/QC’ing that data and making it transparent and available for everyone to use, so they can take that information and work it into their drought planning.

They have done a lot of outreach to those water users so they understand how the Water Board is using the data and how they can help improve datasets by better more consistent and more timely reporting.  He pointed out that within the Delta, they have 100% compliance with water reporting.  But by and large, all the data is being received on a timely basis and they are now working through the QA/QC process. 

Alternative Compliance Plan

The work continues on the alternative compliance plan for complying with the SB-88 regulations to measure diversions in the Delta.  All the diversions in the Delta under SB-88 and the implementing regulations are designed to be measured with a device, a meter, or with some other comparable method to give a high degree of reliability, which, due to the uniqueness of the Delta, is often not possible.  So an ad hoc group called the Delta Measurement Experimentation Consortium has been working the past four years on how to implement the measurement requirement are proposing an alternative.

They are now working on the process to create the software connection between the heritage report management system and the cutting edge Open ET system that is coming online that will use computer analysis of satellite images to identify crop evapotranspiration at the field level.  The alternative plan of compliance is scheduled to be available by January 1, 2022.

Addressing deterioration in the Delta

Delta Watermaster Michael George has been spotlighting the ongoing deterioration in the Delta for a couple of years now.  There has been the extensive deterioration in ecosystem function, flood resilience, water quality, as well as water supply which is due to extensive invasive aquatic weeds and sedimentation of the channels.

A voluntary ad hoc committee that has come together to identify the problem, describe it to broader audiences and is now in the process of releasing a request for proposals for professional consultants to come in and assist the group which will be funded by the group’s voluntary contributions.  The consultant will help define the size of the problem and to define options for dealing with the problem.

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