Tag Archives: water resource management

Close Diablo Canyon? More distributed solar instead

More calls for keeping Diablo Canyon have coming out in the last month, along with a proposal to match the project with a desalination project that would deliver water to somewhere. (And there has been pushback from opponents.) There are better solutions, as I have written about previously. Unfortunately, those who are now raising this issue missed the details and nuances of the debate in 2016 when the decision was made, and they are not well informed about Diablo’s situation.

One important fact is that it is not clear whether continued operation of Diablo is safe. Unit No. 1 has one of the most embrittled containment vessels in the U.S. that is at risk during a sudden shutdown event.

Another is that the decision would require overriding a State Water Resources Control Board decision that required ending the use of once-through cooling with ocean water. That cost was what led to the closure decision, which was 10 cents per kilowatt-hour at current operational levels and in excess of 12 cents in more likely operations.

So what could the state do fairly quickly for 12 cents per kWh instead? Install distributed energy resources focused on commercial and community-scale solar. These projects cost between 6 and 9 cents per kWh and avoid transmission costs of about 4 cents per kWh. They also can be paired with electric vehicles to store electricity and fuel the replacement of gasoline cars. Microgrids can mitigate wildfire risk more cost effectively than undergrounding, so we can save another $40 billion there too. Most importantly they can be built in a matter of months, much more quickly than grid-scale projects.

As for the proposal to build a desalination plant, pairing one with Diablo would both be overkill and a logistical puzzle. The Carlsbad plant produces 56,000 acre-feet annually for San Diego County Water Agency. The Central Coast where Diablo is located has a State Water Project allocation of 45,000 acre-feet which is not even used fully now. That plant uses 35 MW or 1.6% of Diablo’s output. A plant built to use all of Diablo’s output could produce 3.5 million acre-feet, but the State Water Project would need to be significantly modified to move the water either back to the Central Valley or beyond Santa Barbara to Ventura. All of that adds up to a large cost on top of what is already a costly source of water of $2,500 to $2,800 per acre-foot.

Why Californians aren’t meeting the state’s call for more water conservation

Governor Gavin Newsom called for a voluntary reduction in water use of 15% in July in response to the second year of a severe drought. The latest data from the State Water Resources Control Board showed little response on the part of the citizenry and the media lamented the lack of effort. However, those reports overlooked a major reason for a lack of further conservation.

The SWRCB conservation reports data shows that urban Californians are still saving 15% below the 2013 benchmark used in the last drought. So a call for another 15% on top of that translates to a 27% reduction from the same 2013 baseline. Californian’s have not heard that this drought is worse than 2015 yet the state is calling for a more drastic overall reduction. Of course we aren’t seeing an even further reduction without a much stronger message.

In 2015 to get to a 25% reduction, the SWRCB adopted a set of regulations with concomitant penalties which pretty much achieved the intended target. But that effort required a combination of higher rates and increased expenditures by water agencies. It will take a similar effort to move the needle again.

The State Water Board needs to act to start Flood MAR pilot projects

I recently presented to CDWR’s Lunch-MAR group the findings for a series of studies we conducted on the universe of benefits from floodwater managed aquifer recharge (MAR) and the related economic and financing issues. I also proposed that an important next step is to run a set of pilots to study the acceptability of on-farm floodwater recharge projects to growers, including how do they respond to incentives and program design, and what are the potential physical consequences.

The key to initiating these pilots is getting a clear declaration from the State Water Resources Control Board that excess floodwaters are surplus and available. Unfortunately, the Water Board has not provided sufficient clarification on how these projects can take “advantage of seasonal or occasional flood waters that overtop the banks of a stream and are then directed into a designated recharge area.” Instead, the Board’s website says that such diverted floodwaters cannot be stored for future beneficial use–which obviates the very purpose of retaining the floodwaters in the first place.

The Board should be at least issuing temporary use permits for floodwaters above certain designated levels as being available for pilot projects on the basis that non-use of those floodwaters constitute a surrender of that right for the year. Then those agencies interested in flood MAR can design projects to experiment with potential configurations.

“What are public benefits of conveyance?” presented to the California Water Commission

Maven’s Notebook posted a summary of presentations to the California Water Commission by Richard McCann of M.Cubed, Steve Hatchett of Era Economics, and David Sunding of the Brattle Group. Many of my slides are included.

The Commission is developing a framework that might be used to identify how shares of conveyance costs might be funded by the state of California. The Commission previously awarded almost $3 billion in bond financing for a dozen projects under the Proposition 1B Water Storage Investment Program (WSIP). That process used a prescribed method including a Technical Guide that determined the eligible public benefits for financing by the state. M.Cubed supported the application by Irvine Ranch Water District and Rio Bravo-Rosedale Water Storage District for the Kern Fan water bank.

How to choose a water system model

The California Water & Environmental Modeling Forum (CWEMF) has proposed to update its water modeling protocol guidance, last issued in 2000. This modeling protocol applies to many other settings, including electricity production and planning (which I am familiar with). I led the review of electricity system simulation models for the California Energy Commission, and asked many of these questions then.

Questions that should be addressed in water system modeling include:

  • Models can be used for either short-term operational or long term planning purposes—models rarely can serve both masters. The model should be chosen for its analytic focus is on predicting with accuracy and/or precision a particular outcome (usually for short term operations) or identifying resilience and sustainability.
  • There can be a trade off between accuracy and precision. And focusing overly so on precision in one aspect of a model is unlikely to improve the overall accuracy of the model due to the lack of precision elsewhere. In addition, increased precision also increases processing time, thus slowing output and flexibility.
  • A model should be able to produce multiple outcomes quickly as a “scenario generator” for analyzing uncertainty, risk and vulnerability. The model should be tested for accuracy when relaxing key constraints that increase processing time. For example, in an electricity production model, relaxing the unit commitment algorithm increased processing speed twelve fold while losing only 7 percent in accuracy, mostly in the extreme tail cases.
  • Water models should be able to use different water condition sequences rather than relying on historic traces. In the latter case, models may operate as though the future is known with certainty.
  • Water management models should include the full set of opportunity costs for water supply, power generation, flood protection and groundwater pumping. This implies that some type of linkage should exist between these types of models.

Davis Should Set Its Utility Reserve Targets with a Transparent and Rigorous Method

The City of Davis Utilities Commission is considering on February 19 whether to disregard the preliminary recommendations of the Commission’s Enterprise Fund Reserve Policies subcommittee to establish a transparent, relatively rigorous and consistent method for setting City reserves. The Staff Report, written by the now-departed finance director, ignored the stated objectives of both the Utilities and Finance and Budget Commissions to develop a consistent set of policies that did not rely on the undocumented and opaque practices of other communities. Those practices had no linkage whatsoever to risk assessment, and the American Water Works Association’s report that the Staff relied on again to reject the Commission’s recommendation again fails to provide any documentation on how the proposed targets reflect risk mitigation—they are simply drawn from past practices.[1]

The City’s Finance & Budget Committee raised the question of whether the City held too much in reserves over five years ago, and the Utilities Commission agreed in 2017 to evaluate the status of the reserves for the four City enterprise funds—water, sanitation/waste disposal, sewer/wastewater, and stormwater. A Utilities Commission subcommittee reviewed the current reserve policies and what is being done by other cities. (I was on that subcommittee.) First, the subcommittee found that the City was using different methods for each fund, and that other cities had not conducted risk analyses to set their targets either. The subcommittee conducted a statistical analysis that allows the City to adjust its reserve targets for changing conditions rather than just relying on the heuristic values provided by consultants.

The subcommittee’s proposal adopted initially by the Utilities Commission achieved three objectives that had been missing from the previous informal reserves policy. Two of these would still be missing under the Staff’s proposal:

  1. Clearly defining and documenting the reserves held for debt coverage. While these amounts were shown in previous rate studies, the documented source of those amounts generally not included and the subcommittee’s requests brought those to the fore. The Staff method appears to accept continuance of that practice. The Staff proposes to keep those separate, which differs from past practice which rolled all reserves together.
  2. Reserve targets are first set based on the historic volatility of enterprise net income. In other words, the reserves would be determined transparently with a rigorous method on the basis of the need for those reserves. The method uses a target that is statistically beyond the 99th percentile in the probability distribution. And this target can be readily updated for new information each year. The Staff report rejects this method to adopt a target that refers to the practice of other communities, and none of those practices appear to be based on analytic methods from research done by the subcommittee.
  3. Reserve targets are then adjusted to cover the largest single year capital improvement/replacement investment made historically to ensure enough cash for non-debt expenditures. Because the net income volatility is a joint function of revenues, operating expenditures and non-debt capital expenditures, the latter category is not separated out of the analysis. However, an added margin can be incorporated. That said, the data set for the fiscal years of 2008/2009 to 2016/2017 used by the subcommittee found that setting the target based on the volatility has been sufficient to date. The Staff report appears to call for a separate, unnecessary reserve fund for this purpose based on annual depreciation that has no relationship to risk exposure, and implicitly duplicates the debt payments already being made on these utility systems. This would be a wasteful duplication that sets the reserves too high.

The Finance and Budget raised at least two important issues in its review:

  1. Water and sewer usage and revenues may be correlated so that the reserves may be shared between the two funds. However, further review shows that the funds have a slight negative correlation, indicating that the reserves should be held separately.
  2. The water fund already has an implicit reserve source when a drought emergency is declared because a surcharge of 25% is added to water utility charges. I agree that this should be accounted for in the historic volatility analysis. This reduces the volatility in fiscal years 2014/2015 and 2015/2016, and reduces the water fund volatility reserve from 26% to 21%.
  3. Working cash reserves are unnecessary because the utility funds are already well established (not needing a start up reserve), and that the volatility reserves already cover any significant lags in the revenues that may occur. This observation is valid, and I agree that the working cash reserves are duplicative of the other reserve requirements. The working cash reserves should be eliminated from the reserve targets for this reason.

Finally, the Staff proposal raises an issue about the appropriate basis for determining the sanitation/waste removal reserve target. The Staff proposes to base it solely on direct City expenses. However, the enterprise fund balance shows a deficit that includes the revenues and expenses incurred by the contractor, first Davis Waste Removal and then Recology. We need more specificity on which party is bearing the risk of these shortfalls before determining the appropriate reserve target. Given the current City accounting stance that incorporates those shortfalls, I propose using the Utility Commission’s proposed method for now.

Based the analysis done by Utilities Commission subcommittee and the recommendations of the Finance & Budget Committee, the chart above shows the target % reserves for each fund without the debt coverage target. It also shows the % reserve targets implied by the Staff’s proposed method.[2] The chart also shows corresponding dollar amount for the proposed total target reserves, including the debt reserves, and the cash assets held for those funds in fiscal year 2016/2017. Importantly, this new reserve target shows that the City held about $30 million of excess reserves in 2016/2017.

[1] It appears the Staff may have misread the Utilities Commission’s recommendation memorandum and confused the proposed targets policies with the inferred existing policies. This makes it uncertain as to whether the Staff fully considered what had been proposed by the Utilities Commission.

[2] The amounts shown in the October 16, 2019 Staff Report on Item 6B do not appear to be consistent with the methodology shown in Table 1 of that report.

Moving forward on Flood-MAR with pilots

The progress on implementing floodwater managed aquifer recharge programs (Flood-MAR) reminds me of the economist’s joke, “sure it works in practice, but does it work in theory?” A lot of focus seems to be on trying to refine the technical understanding of recharge, without going with what we already know about aquifer replenishment from decades of applications.

The Department of Water Resources Flood-MAR program recently held a public forum to discuss its research program. I presented a poster (shown above) on the findings of a series of studies we conducted for Sustainable Conservation on the economic and financial considerations for establishing these programs. (I posted about this last February.)

My conclusion from the presentations and the other publications we’ve followed is that the next step is to set up pilots using different institutional set ups and economic incentives. The scientists and engineers can further refine their findings, but we generally know where the soils are better for percolation versus others, and we know that crop productivity won’t fall too much where fields are flooded. The real issues fall into five categories, of which we’ve delved into four in our Floodwater Recharge Memos.

Benefits Diagrams_Page_5

The first is identifying the beneficiaries and the potential magnitude of those benefits. As can be seen in the flow chart above, there many more potential beneficiaries than just the local groundwater users. Some of these benefits require forecast informed reservoir operations (FIRO) to realize those gains through reduced flood control space, increased water supply storage and greater summertime hydropower output. Flood-MAR programs can provide the needed margin of error to lower the risk from FIRO.

FloodMAR Poster - Financing

The second is finding the funding mechanisms to compensate growers or to build dedicated recharge basins. We prepared a list of potential financing mechanisms linked to the potential beneficiaries. (This list grew out of another study that we prepared for the Delta Protection Commission on feasible options for beneficiary-pays financing.)

FloodMAR Poster Incentives

The third is determining what type of market incentive transactions mechanisms would work best at attracting the most preferred operations and acreage. I have explored the issues of establishing unusual new markets for a couple of decades, including for water rights transfer and air quality permit trading. It is not a simple case of “declaring markets exist” and then walking away. Managing institutions have important roles in setting up, running and funding any market, and most particularly for those that manage what were “public goods” that individuals and firms were able to use for free. The table above lists the most important considerations in establishing those markets.

The fourth assessing what type of infrastructure investment will produce the most cost-effective recharge. Construction costs (which we evaluated) is one aspect, and impacts on agricultural operations and financial feasibility are other considerations. The chart at the top summarizes the results from comparing several case studies. These will vary by situation, but remarkably, these options appear to cost substantially less than any surface storage projects currently being proposed.

The final institutional issue to be addressed, but not the least important, is determining the extent of rights over floodwaters and aquifers. California state law and regulations are just beginning to grapple with these issues. Certain areas are beginning to assert protection of their existing rights. This issue probably represents the single biggest impediment to these programs before attracting growers to participate.

All of these issues can be addressed in a range of pilot programs which use different variables to test which are likely to be more successful. Scientists and engineers can use these pilots to test for the impacts of different types of water diversion and application. Statistical regression analysis can provide us much of what we know without having to understand the hydrological dynamics. Legal rights can be assessed by providing temporary permits that might be modified as we learn more from the pilots.

Is it time to move forward with local pilot programs? Do we know enough that we can demonstrate the likely benefits? What other aspects should we explore before moving to widespread adoption and implementation?

Using floods to replenish groundwater

ALMOND  ORCHARD FLOODING

M.Cubed produced four reports for Sustainable Conservation on using floodwaters to recharge aquifers in California’s Central Valley. The first is on expected costs. The next three are a set on the benefits, participation incentives and financing options for using floodwaters in wetter years to replenish groundwater aquifers. We found that costs would range around $100 per acre-foot, and beneficiaries include not only local farmers, but also downstream communities with lower flood control costs, upstream water users with more space for storage instead of flood control, increased hydropower generation, and more streamside habitat. We discussed several different approaches to incentives based on our experience in a range of market-based regulatory settings and the water transfer market.

With the PPIC’s release of Water and the Future of the San Joaquin Valley, which forecasts a loss of 500,000 acres of agricultural production due to reduced groundwater pumping under the State Groundwater Management Act (SGMA), local solutions that mitigate groundwater restrictions should be moving to the fore.

Don Cameron at Terranova Ranch started doing this deliberately earlier this decade, and working with Phil Bachand and UC Davis, more study has shown the effectiveness, and the lack of risk to crops, from this strategy. The Department of Water Resources has implemented the Flood-MAR program to explore this alternative further. The Flood-MAR whitepaper explores many of these issues, but its list of beneficiaries is incomplete, and the program appears to not yet moved on to how to effectively implement these programs integrated with the local SGMA plans. Our white papers could be useful starting points for that discussion.

(Image Source: Chico Enterprise-Record)

 

 

 

Building Drought Resilience in California’s Cities and Suburbs from PPIC

Then And Now: California's Drought Officially Declared To Be Over

M.Cubed partner David Mitchell is the lead author on this PPIC report that reviews the responses by urban agencies to the California’s recent drought and looks at the lessons learned. He’s speaking during a webinar on June 16 at noon. In addition, he co-authored an opinion article for the Sacramento Bee.

Current winter setting a new California-wide record precipitation accumulation | Center for Western Weather and Water Extremes (CW3E)

Source: Current winter setting a new California-wide record precipitation accumulation | Center for Western Weather and Water Extremes (CW3E)