Imbalances in the Colorado River Basin continue to grow
Looming shortages in the Colorado River Basin were the central focus of the Board’s afternoon agenda on Tuesday, July 19th.
During the four-hour-long agenda item, River District Directors heard from Andy Mueller, General Manager of the Colorado River District; Kevin Rein; State Water Engineer; Chuck Cullom, Executive Director of the Upper Colorado River Commission; and Katrina Grantz, Assistant Director for the Upper Colorado Basin at the U.S. Bureau of Reclamation.
Below is a brief summary of the discussion. The full recording can be found here.
In the District
On June 14th, Camille Touton, Bureau of Reclamation Commissioner, testified to a Senate Committee that the seven states in the Colorado River Basin need to develop plans to reduce their total consumptive use by between 2 and 4 million acre feet before the middle of August. If the states are not able to do so, the Commissioner indicated that the Bureau of Reclamation will take unilateral action to reduce system consumption.
Andy Mueller shared the perspective of the River District. “The Upper Basin states have taken the Commissioner’s words at face value and are working cooperatively together to develop and implement plans to reduce Upper Basin Consumptive uses.”
The urgency of the situation is apparent even in national headlines. The inflow into Lake Powell continues to be extremely poor. The combination of the poor hydrology and the Lower Basin’s continued high depletions from Lake Mead have set up a significant crisis in the management of the Colorado River.
Mueller stressed that any meaningful solution must address the continued overuse of the Colorado River’s waters by the Lower Basin states (Arizona, California and Nevada) which have taken no shortages until this year, despite the drastically reduced hydrology of the last twenty-plus years. Without those reductions, there is understandable concern that any Upper Basin conserved water will simply be funneled through the Hoover Dam and irretrievably consumed by the Lower Basin.
While the Upper Basin’s consumptive uses from the Colorado River System declined from 4.5 million acre feet to approximately 3.5 million acre feet, between 2019 and 2021, during the same period, the Lower Basin’s mainstem consumptive depletions from the system have increased by over 600,000 acre feet.
However, if the Colorado River’s hydrology average yield no longer sustains enough water for each basin to receive its share under the Compact of 1922 (7.5 million acre-feet per year for the Upper and Lower basin states), each state may need to play a part in curtailing water use. Colorado does not have a playbook for how cuts to water users would be administered within the state.
State of Colorado
State Engineer Kevin Rein discussed the mechanics of a Colorado River Compact curtailment and the steps his office is or is not taking to prepare for such a possibility.
“We are in compliance with the Compact,” Rein pointed out. “When it comes to using our allocation, we are way under. At the state engineer’s office, there is nothing telling me to curtail. In fact, if you have the legal right to water, and a beneficial use to put to it, then I’m encouraging people to use their water.”
Rein stated that he does not believe the Compact will become an issue at least through the year 2025.
Both Andy Mueller and Director Taylor Hawes (Summit County), pressed Rein on why the state still has not shared its protocol for administering Compact Compliance. Hawes suggested that the state spend more time investigating what she called “no-regret steps” which would move us forward without taking a toll on water users.
“What about shepherding water?” Hawes asked. “Can we develop more tools to be able to measure and shepherd water as it travels through our state?”
Directors were insistent on understanding when they would see some rule-making progress, but Rein declined to offer any definitive timeline.
Upper Colorado River Commission
The next presenter was Chuck Cullom, Executive Director of the Upper Colorado River Commission (UCRC). Cullom opened by identifying some of the major differences between the management of water in the Upper and the Lower Basin states.
“Your systems here in the Upper Basin are supply dominated,” Cullom observed. “That is a fundamentally different framework of thinking than the Lower Basin which sits downstream of the two largest reservoirs in the country. When a water user in the Lower Basin puts in their order on January 1st, they can plan for that water being delivered. No uncertainty.”
He went on to share how, while there are hundreds of diversions in Colorado, ditches and headgates scattered along the many rivers and tributaries, in the Lower Basin there are only about 25 major “turnoffs” that play into how the system is managed. While in Colorado, one water user’s diversion has cascading effects on the water use of their neighbors, in the Lower Basin, users do not have to wonder how much water they will ever have day to day.
Cullom also pointed out that the accounting of water use in the Lower Basin is different than the realities seen by headwaters states. “[The Bureau of Reclamation] does not assess the physical tax of evaporation and loss against anyone’s water rights. This is the significant driver of the structural deficit.”
In response to the Bureau of Reclamations call for a reduction of 2-4 million acre feet in 2023, the Upper Colorado River Commission recently sent a letter to the Bureau of Reclamation offering a five– point plan to address water conservation across the states of Colorado, Wyoming, Utah and New Mexico. The five points are summarized below, you can read the letter here.
- Reauthorize and fund the System Conservation Pilot Project
- Commence development of a 2023 Drought Response Operations Plan
- Consider an Upper Basin Demand Management program
- Use Bipartisan Infrastructure Law funding to accelerate enhanced measurement, monitoring, and reporting
- Continue strict water management and administration within the available annual supply
The Lower Basin states have yet to provide a clear plan to address the Bureau’s water use directive in any significant way.
Bureau of Reclamation
The final presentation was by Katrina Grantz, Assistant Director for the Upper Colorado Basin at the U.S. Bureau of Reclamation. She shared the data and forecast modeling which compelled the Bureau to increase the urgency in its communication with basin states and stakeholders.
A consistent theme in Grantz’s presentation, one which was echoed in many other discussions throughout the board meeting, was how important accurate modeling is to water managers across the West. Unfortunately, in recent years, those models have failed to accurately predict streamflow based on snowpack. In fact, early season forecasts have consistently over-estimated inflow to Lake Powell (and other reservoirs). This is partly due to unprecedented drought, as most models rely on historical data. (link to hydrology).
Grantz pointed out that only once between 1964 and 2000 did inflow into Powell drop below 7 million acre feet for two consecutive years. However, since 2000, this has occurred three separate times. “We are seeing not only drier years,” she said. “But drier back-to-back years.”
According to Grantz, these lower flow years, when juxtaposed, exponentially increase the likelihood of Lake Powell falling below not only the target elevation of 3525’, but also below the power pool of 3490’. It is at this level that Glen Canyon Dam can no longer produce electricity.
However, as Grantz confirmed to the Board, the biggest concern for the Bureau of Reclamation is not power production, but rather the inability to send water safely downstream. Once the dam is out of operation, the bypass tunnels would become the primary means of delivering water to Mead through the Grand Canyon. The bypass tunnels were not designed to be used in this capacity and significant safety concerns exist around possibly erosion. 
Once the stakes were established, Grantz explained how the Bureau of Reclamation’s “Protection Volume Analysis and Results” projected exactly how much water would be needed to protect those critical levels. These results were what dictated the unprecedented Drought Operations Plan in 2022 which will release 500,000 from Flaming Gorge and lower the release from Powell to 7 million acre feet.
Lake Powell Necessary Protections slide image
Grantz re-iterated that while major cuts are necessary, useful solutions can only be found if the burden is shared across the entire basin and in every sector.
After Grantz’s presentation, Mueller suggested that the Bureau revisit the accounting used to determine Compact compliance- I.e. how much water the Upper Basin delivers to the Lower. Currently, the BoR does not take into account any losses due to transit and evaporation. “We’re talking 1.1 to 1.3 million acre feet per year, and over the last twenty years, that adds up to almost the content of Lake Powell. We get charged for all of that. There’s a failure of proper accounting in the Lower Colorado Region.”
Grantz said that it’s a complicated legal answer with a lot of interlocking pieces, and she concluded by saying, “We aren’t there, yet. And we need to look at a whole range of solutions.”
