Pilot project aims to improve reservoir operations in Texas Posted on May 9, 2023

How new technology could impact future water supply reliability and flood control

With summer just around the corner, many Texans are planning visits to cool off at lakes across the state. While recreational use is a nice bonus, most of these water destinations were built to serve as reservoirs that play a crucial role in the state’s water supply and flood mitigation strategies. Reservoir operators are tasked with monitoring the water levels at these sites, which can be a delicate balance in a state that experiences both frequent flooding and drought.

Recent improvements to weather and hydrologic predictions have motivated water agencies to explore how these predictions can potentially be used for reservoir operations to alleviate the impacts of droughts and select flood events. This methodology, known as forecast-informed reservoir operations (FIRO), uses forecasted rainfall and real-time information on water inflows to reservoirs, rainfall in the watershed, and water demands on the reservoirs to adapt operations and better manage water supply. These predictions can be used to increase water supply by selectively storing water from rainfall events rather than releasing it downstream.

“If you can safely increase the amount of water being held temporarily in the flood control pool, you are able to increase supply temporarily,” said Dr. Nelun Fernando, Manager of the Water Availability Program at the Texas Water Development Board (TWDB). “FIRO offers the potential to help ensure water availability during periods of drought in a cost-effective way.”

The TWDB is partnering with the University of Texas at Arlington, the United States Army Corps of Engineers Fort Worth District, the National Weather Service West Gulf River Forecast Center, and the Brazos River Authority on a FIRO pilot project in the Little River watershed region of the Brazos River basin. With funding from the United States Bureau of Reclamation, the project began in the summer of 2022 to study how temporary deviations to water stored in Lake Georgetown’s flood pool can be strategically retained using improved rainfall forecasts.

This pilot project stemmed from a 2019 workshop organized by the TWDB, the University of Texas at Arlington, and the National Oceanic and Atmospheric Administration’s (NOAA’s) National Integrated Drought Information System to determine if FIRO could be a viable strategy for reservoir operators in Texas. The workshop brought together reservoir operators, forecasters, researchers, water suppliers, and other stakeholders to identify the issues that make FIRO operations in Texas more challenging in comparison to other states. For example, because Texas is such a large state with diverse climates, the storm systems responsible for runoff and flooding are more difficult to predict beyond a short timeframe.

As part of the pilot project, partners convene monthly to share problems or gaps that arise in the forecasts to help inform and improve NOAA products that are currently in the research phase. The results of the project will inform and shape upcoming Texas FIRO activities, which will ultimately produce FIRO guidelines and practice.

“Floods and droughts are proverbial grand challenges confronting the state of Texas. FIRO, if effectively practiced, has the potential to help address water reliability and flood risks,” said Dr. Yu Zhang, Associate Professor, Department of Civil Engineering at the University of Texas at Arlington. “The Brazos FIRO pilot is the first step towards this goal. Its vision is to facilitate broad, objective integration of National Weather Service ensemble streamflow and weather forecasts in reservoir operations in the state of Texas.”

The pilot project is scheduled to conclude in the summer of 2025. While more research is needed before FIRO can be widely implemented as a water management strategy, it may be a cost-effective approach to increasing resilience to flooding and drought in Texas.

In September 2023, the TWDB, the University of Texas at Arlington, and the National Integrated Drought Information System will jointly host the second Texas FIRO workshop.

One notable example where FIRO is being implemented in the United States is at Lake Mendocino in Northern California. That pilot program involved making temporary changes to the reservoir’s established operating rules to incorporate the use of forecasts to determine reservoir releases. During operational testing in 2019 and 2020, the use of FIRO helped manage flood risks and increased water storage in Lake Mendocino by almost 20 percent.

This article is posted in Flood / Technology / Weather / Drought / Water Supply .