Established in 1887 as the first irrigation district in California and with an irrigation system built in the early 1900s, Turlock Irrigation District (TID) has spent $60 million over the past 20 years maintaining aging infrastructure while modernizing to save water and meet future needs. It is also moving forward with existing initiatives such as Project Nexus, a pilot project that will install solar panel canopies over sections of the district’s irrigation canals. In this interview, General Manager Michelle Reimers tells Irrigation Leader about the district’s efforts to build on its past while responding to the challenges of a less-predictable climate.
Irrigation Leader: Please tell us about your background and how you came to be in your current position.
Michelle Reimers: I started with the district in 2006 as a communications specialist. My degree is in organizational communications, and my hope was to work in an advertising agency, but there aren’t a lot of options for that in Turlock. My grandparents had an almond orchard, and when I was young, I spent my summers helping them farm. Because of that experience, I was interested in agriculture and water. That’s what led me to apply for a public information officer job at TID. Later, I was promoted to oversee government affairs. Eventually, I became the assistant general manager of external affairs, overseeing communications, government affairs, customer service, and all our public benefit programs on the energy side. In 2020, I became the general manager.
Irrigation Leader: Please tell us about TID’s history and its current services.
Michelle Reimers: We were the first irrigation district established in California and are currently celebrating our 135th anniversary. Our irrigation system was built in the early 1900s, and it still serves us today. We’re one of only four utilities in California that provide both water and retail electricity. We irrigate about 150,000 acres and serve about 4,700 growers. On the energy side, we provide power to about 239,000 people in our service area. We are also a balancing authority, which means we have a diverse portfolio of power generation and have the reliability requirements to protect our service territory from any kind of statewide rolling blackout. On the water side, we receive our water from the Tuolumne River, which starts in Yosemite National Park. We supply mostly surface water, but we also use groundwater. We’ve done conjunctive use since our inception.
Irrigation Leader: What are the main crops grown by your irrigators?
Michelle Reimers: The main crop is tree nuts, including almonds and walnuts, but we also have corn, oats, and alfalfa, which support the dairies, which are a big industry here as well.
Irrigation Leader: What infrastructure does TID own and operate?
Michelle Reimers: We operate Don Pedro Reservoir, a 2‑million-acre-foot reservoir that we own in conjunction with Modesto Irrigation District. TID is the operator of the 203‑megawatt hydroelectric facility there. The two districts also own the La Grange Diversion Dam, which was built in 1893. That dam doesn’t hold water; it just backs it up enough to divert it into our canal systems. We have 250 miles of gravity-fed canals. We also have Turlock Lake, a 50,000 acre-foot regulating reservoir where we hold the water that starts the irrigation system.
On the energy side, we have a diverse power portfolio. We own a couple of natural gas–fired power plants. In addition to our large hydro facility, we have some small hydro on our canal systems. We also own a wind farm in Washington State, and we have a power purchase agreement with a solar field in Lancaster, California.
Irrigation Leader: To what degree is your source of water susceptible to cutbacks during drought years?
Michelle Reimers: Unlike the many fill-and-spill reservoirs in California, our system is built to weather droughts, and we manage it differently. In response to a drought, we can start making cutbacks earlier than others do. Our reductions aren’t as drastic as those you hear about at state and federal projects, where often the numbers are altered or adjusted monthly depending on what is happening with the hydrology, sometimes going down to a zero allocation. We have more flexibility because we own, operate, and manage our own resources. That’s proved to be beneficial to our growers.
Irrigation Leader: How has climate change affected TID’s operations, and how is the district seeking to better navigate drought cycles?
Michelle Reimers: Climate change is real. We’re finding that wet years are wetter, dry years are happening more frequently, and dry periods are longer in duration. In 2012, we started measuring the snow in our watershed with the help of the U.S. Department of Agriculture and a company called Airborne Snow Observatories (ASO). Essentially, ASO takes a plane up in the watershed and uses lidar to take precise measurements that are 97–99 percent accurate. That is dramatically different from the approach used by the California Department of Water Resources (DWR), which puts a stick in the snow to measure its depth and takes maybe 17 measurements in a huge watershed. We’re also partnering with the Scripps Institute of Oceanography and its forecast-informed reservoir operations program to learn more about atmospheric rivers, which are severe precipitation events. We are also one of the only agencies that use an hourly hydrological model. It was custom built for our watershed. It takes all the data from our 135‑year history to help us understand how our watershed is handling the climate.
I’ll give you a couple of examples to illustrate how useful these predictive tools are. The year 2017 was really wet. That was the year when Oroville Dam had a partial failure. We, too, had to use our spillway. The difference, however, is that we had seen what was coming and what was up in the watershed, and we asked for a deviation from the U.S. Army Corps of Engineers to start releasing. We released water 17 days earlier than what the flood control manual would have told us to. Starting early allowed us to open just one of our three spillway gates, which is huge for us. We own the flood obligations on the Tuolumne, and our river channels are narrow, so opening three spillway gates would have caused significant damage downstream. The next year, the same technology informed us that the snow content wasn’t as robust as everybody had thought, so again we asked the Army Corps for a deviation. We saved about 150,000 acre-feet of water that year. Finally, we did an ASO flight in February 2021 and again saw that the snow content wasn’t as ample as people thought. We were able to start making cutbacks. We brought the data to the TID board of directors, and they set the annual amount of available water for growers accordingly. Our calculations were off by less than 2 percent. The state’s forecast, however, was off by 700,000 acre-feet.
Irrigation Leader: Given that you are in the third consecutive year of drought, what has TID done to conserve and most efficiently use the water that is available?
Michelle Reimers: We are investing more in the lower end of our system. It’s a gravity-fed system that is meant to spill, but in an era like this, every drop matters. We’re making a lot of investments in automatic gates. Turlock Lake is a regulating reservoir, and we constructed another reservoir downstream in our system that works on the same concept. It temporarily stores water so that we can start the system over again, which saves water. It has reduced the groundwater pumping in the area and gets water to customers more quickly. We’re looking at adding additional regulating reservoirs to our system.
Irrigation Leader: How have the Sustainable Groundwater Management Act (SGMA) and other regulatory initiatives affected the district?
Michelle Reimers: I wouldn’t necessarily say that SGMA has hit us negatively, because we have basically been using surface water and groundwater conjunctively since our inception. We were one of the only areas that were not critically overdrafted. We have a long history of flood irrigating and recharging the aquifer in wet years and then using that underground water in drier years. We’ve also been monitoring groundwater for decades. One positive outcome of SGMA is that neighboring areas and cities included in our groundwater sustainability agency (GSA) have had to analyze their groundwater practices. Forming the GSA brought all the partners that pump groundwater into one room to have conversations about solutions for the future. If any reduction in pumping is required, we prefer that it is done in a healthy and balanced way to keep the aquifers sustainable.
A lot of state regulatory actions have affected us, specifically those that pertain to river flows and the relicensing of the Don Pedro Project. We’re in litigation over that. It’s made it challenging to understand how much additional water the state would like and whether it’s for the environment or to supplement the state’s supplies where they’re short. When you don’t have certainty, it’s hard to plan. With that said, we are moving forward on seeking additional water storage in our system. Initially, we were looking to increase storage in Don Pedro, and while that is still on the table, we are also taking another look at how we can add more storage throughout the system.
Irrigation Leader: Please tell us about your repair and modernization efforts.
Michelle Reimers: We’ve spent about $60 million on our irrigation system in the past 20 years. Drop automation is a priority for the district. We have about 400 drops and about 1,600 side gates in our system. We’ve permanently installed 122 Rubicon SlipMeters and have another 79 Rubicon FlumeMeters that rotate throughout the system. We are trying to automate in a thoughtful and affordable way, since all our costs are passed directly to our customers. We’ve implemented the regulating reservoir, which saves us about 9,000 acre-feet of water each year; we are working on building another; and when that is complete, we have another on the docket. About 90 percent of our canals are lined. It takes a huge amount of time and money each year just to make sure they’re maintained. The hydroelectric plant at the Don Pedro Project is over 50 years old and is at the end of its useful life. We are in the process of replacing the turbines. The goal is to extend the life of the plant for another 50 years
Irrigation Leader: You were selected to launch Project Nexus, a pilot to install solar panels over irrigation canals. Please tell us about this project.
Michelle Reimers: California has imposed a goal of reaching 60 percent renewable energy by 2030 and going 100 percent carbon free by 2045. With our land valued at $50,000– $70,000 an acre, it wouldn’t make sense to take farmland out of production to install solar panels or other forms of renewable energy facilities. I came across an article about a study on installing solar over canals that the University of California, Merced, had just completed and thought, “We have 250 miles of those—maybe this is something we should look at.” We reached out to the University of California, Merced, where researchers were working with a private firm that had developed this concept. We met all the selection criteria, which is how we were chosen for the pilot project. It is the first public-private-academic partnership in the United States. DWR is also involved because $20 million in the state budget was allotted to test this concept.
We have selected two areas in which to install the panels: one in the upper system over a canal with a 110‑foot span and the other in an area with a 20‑foot span. We are supposed to break ground by the end of this year, so the project should be up and running by our next irrigation season. The project will produce about 5 megawatts of renewable energy. We’ll be studying its effects on evaporation. More importantly, we’re hopeful that the shade will reduce the algae in our system. It is really hot here, over 100 degrees at the height of the summer, and we get a lot of algae growth in our canals. That is expensive to treat both physically and chemically. We’re excited to see whether this approach helps solve that issue in addition to generating renewable energy.
Irrigation Leader: What are the district’s other top issues today?
Michelle Reimers: We’re relicensing the Don Pedro project with the Federal Energy Regulatory Commission to hopefully receive a new 40–50 year license. We are in litigation with the state over the regulatory flow requirements of the Bay-Delta Water Quality Control Plan Update. We’re also working through SGMA. Modernizing our system in a thoughtful way has been a top priority. Climate change and regulatory uncertainties mean we need to think outside the box. We’re looking at additional storage. On the energy side, we’re focused on reliability, making sure we’re resourced appropriately, and meeting all the mandated thresholds that have been placed upon us.
Irrigation Leader: What is your vision for the future?
Michelle Reimers: I take pride in the fact that we were the first irrigation district in California. We want to continue to be a leader in both the water and energy landscapes. We’re taking advantage of new opportunities and modernizing our systems while also respecting what we’ve built and not walking away from that. We are striking the balance between honoring the past and adapting for the future.