Colorado River Basin Water Supply Conditions – Below Normal…Again
The hydrology report presented at the Second Quarterly Board Meeting of 2022 was much the same as the last.
Dave Kanzer, Director of Science and Interstate Matters, and Don Meyer, Senior Water Resources Engineer, once again shared data telling a story of below-average snowpack, above-average temperatures, low runoff forecasts, and dry conditions in the soil and the atmosphere.
“Aridification is a trend that has been observed in the Colorado River Basin over the last 22 years, and the ‘mega-drought,’ as it has become to be called, is not abating,” said Kanzer.
Unfortunately, one important metric did change since the previous board meeting, which Kanzer discussed during his basin-wide analysis: Lake Powell dropped below the ‘target elevation’ of 3,525 feet in March.
Water managers originally chose this target elevation to protect the hydropower production capabilities of Glen Canyon Dam. Turbine efficiency is compromised the lower the lake level drops, and it becomes entirely impossible below the level of 3,490 feet. Water releases coordinated by the Bureau of Reclamation last fall were intended to protect this critical elevation, with almost 181,000 acre feet of water released from the storage reservoirs in the Upper Basin states. Blue Mesa, for example, was drained to almost 25% of its capacity. These releases were projected to raise the level of Lake Powell by three feet, however, due to consistently below-average inflow, Powell has only continued to drop.
The reservoir is currently hovering around 3,522 feet as spring inflow has slowed its descent.
The Colorado Basin River Forecast center currently predicts that flows into Lake Powell will be less than 70% of average. Kanzer reminded the Board of Directors that this new average, and any other average which relies on data from the National Oceanic and Atmospheric Administration (NOAA), is a ‘new normal.’ Current averages are calculated from environmental conditions present in the years of 1991 to 2020 – a significantly drier period than the previous 30-year average, which included the epic eighties.
Since the Board of Directors adjourned, the Bureau of Reclamation has released the 2022 Drought Response Operations plan. This water management plan will prioritize keeping Lake Powell at or above the target elevation by releasing 500,000 acre-feet of water from Flaming Gorge Reservoir.
On the West Slope
Hydrological conditions within the boundaries of the River District are also facing considerable strain, and Don Meyer shared that it is unlikely that any local reservoirs will fill in Water Year 2022.
“These conditions, the lower-than-normal snowpack and dry soils, lead to higher demands for water. This is going to negatively impact reservoir storage across the Upper Colorado River Basin and the prospect for refilling them is not optimistic.”
Precipitation has been inconsistent and unpredictable. Powerful storms in December and January backed up against extremely dry weeks in January and February. The total amounts of snow are currently close to seasonal total averages, but forecasters are not expecting run off to change the outlook in any significant ways.
Across the basin as a whole and within the river district, dry soil conditions persist. All the melting snow must overcome this significant deficit before it can become streamflow. The northwestern corner of the state in particular faces aridity both in the local soil and atmosphere, and high winds are keeping humidity levels at historic lows.