Tag Archives: Flood MAR

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.

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


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)