Turlock Irrigation District (TID) is the first publicly owned irrigation district in the state of California and is one of only four today that provides irrigation water and power to residential, commercial, industrial and agricultural customers. The district has historic water rights dating back to the late 1850’s, with most of the water it supplies to growers diverted from the Tuolumne River.
In 1923, TID, along with Modesto Irrigation District, built the first Don Pedro Dam to store irrigation water and generate carbon-free hydroelectric power for customers in the Central Valley of California. It was the construction of the dam that propelled TID to become a public power agency. Currently, the Don Pedro powerhouse has the capacity to provide a total of 203 MW of hydroelectric power.
Excellence Through Technology
Through private, state and federal partnerships, TID has been able to pioneer the use of innovative technologies through its Airborne Snow Observatory (ASO) program and Forecast-Informed Reservoir Operations (FIRO) program, both of which support the enhancement of TID’s water management operations. The ASO uses Light Detection and Ranging (LiDAR) technology to measure snow depth across vast areas, providing a highly accurate assessment of snowpack and water content affecting the Tuolumne River Watershed. Using these tools, TID integrated these tools into its own in-house hydrologic models. The Hydrocomp Forecasting and Analysis Model (HFAM) is one of the only hourly and physically-based models used for water operations in the state of California.
2023 Water Year Challenges
'Water Year' refers to the period between October 1 and September 30 of the following year as the period hydrologists and water managers use to report precipitation and water-related data. 2023 was one of the wettest years on record in California. The state recorded 141% of its average precipitation statewide, with the Sierra Nevada snowpack reaching an impressive 237% of average by April 1.
This spike in water availability required TID's Hydrology team to be nimble in how they prepared to make flood control releases based on the increasing elevation of the reservoir, current snowpack conditions, and the knowledge of additional forecasted storms. At the same time, the Power team was facing historical hikes in natural gas prices, which would have undoubtedly impacted the cost to provide power to their electric customers.
TID's incredibly accurate data enabled operators to make the decision to make pre-flood releases when their reservoir was only at a level of 700 feet, nowhere near flood control level of 801 feet. Without the use of technology, such action would have been highly questioned in the past. The reliable forecasting and modeling showed that there would be more precipitation coming to the area, and that the quality of the snowpack would enable early releases while still finishing the year with a full reservoir.
“The use of new technologies and data increases drought resilience, improves flood protection for our communities, and proved invaluable when operating the Don Pedro Dam and Powerhouse during the 2023 water year. Without TID’s historic investment in modeling and incorporation of technology and data in partnership with private, state and federal entities, it would have been very difficult for the TID Board to make such a consequential decision to release water before runoff was behind Don Pedro Dam.,” stated TID General Manager Brad Koehn.
Early releases were critical to evacuate water consistently to provide room for flood control, and to maximize the use of that water as free fuel for hydrogeneration. The resulting hydropower generated created a nearly $20 million offset of natural gas purchases typically required to run the district’s natural gas power plants. Additionally, early releases meant the district's actions were not compounding the impact of neighboring agency releases later in the season.
Turlock Irrigation District’s operational excellence is the result of proactive leadership and long-range planning. Taking advantage of technological advancements, securing funding to develop customized forecasting tools, and putting in place the infrastructure to provide reliable, cost-efficient service to their customers enabled them to ride the 2023 wave of water in a manner that validates the impact of years of proactive management.
In recognition of the years of effort that culminated in a successful water management outcome in an extraordinary year, Turlock Irrigation District is the recipient of the CSDA 2024 Excellence in Technology Award. The award was presented to TID General Manager Brad Koehn by CSDA President Pete Kampa in January 2025.
"I was honored to personally present the Excellence in Innovation and Technology to the Turlock Irrigation District (TID)", stated CSDA President Pete Kampa. "As one of the first special districts formed in the state of California, TID continues to strategically push to the cutting edge of innovation in the water and power industry, much to the benefit of their customers and the population in general. By implementing this technology, they not only maximized hydroelectric power generation and its revenue, but also at the same time kept this local reservoir in a pristine, full condition to the benefit of recreation, the environment, agricultural community and the local economy."
“TID is proud to be an industry leader in reservoir and watershed management operations through our use of technology, and we are honored to be recognized by CSDA. We appreciate the unique challenges facing special districts and the opportunity to both support our CSDA peers and learn from their experiences,” stated Koehn.