Dropping water levels at Lake Powell will have growing impact on San Juan County
Dropping elevations at Lake Powell continue to have impacts in San Juan County with longer-reaching impacts on the area if levels at the lake continue to drop.
Access to Lake Powell via Halls Crossing motorized boat launch in San Juan County closed on July 21, 2021, as a result of dropping lake levels, and has yet to re-open.
When it will re-open depends on rising levels from the lake. Coming off the heels of a dry winter it's unclear when that might happen, if it does at all, in 2022.
The United States Bureau of Reclamation a federal agency that oversees water resource management shared in March that a very dry January and February decreased the snowpack that feeds into the Colorado River Basin and Lake Powell.
As a result, Lake Powell’s projected unregulated inflow forecast for water year 2022 was decreased by approximately 2.2 million acre-feet from January through February.
The National Parks Service (NPS) at Glenn Canyon Recreation Area is taking steps to continue access to the lake in lower levels with ramp expansion projects underway at the south end of the lake in Arizona as well as in the north in Kane County, Utah.
While work is underway to extend the ramp at Bullfrog in Kane County. The NPS said last summer that the Halls Crossing Ramp cannot be extended due to the area’s topography.
That means access to the lake via Halls Crossing will remain closed to motorized vessels until lake levels rise high enough for it to re-open.
Similarly, the Charles Hall Ferry which connects Highway 276 across the lake does not operate at lake elevations below 3,575 feet.
Levels were last high enough for Halls Crossing motorize launch in July 2021. During May and June of 2021, Lake Powell levels were listed at 3,560 feet. At the end of July, lake elevations were at 3,553 feet.
The last readings at the lake were at 3,522 feet elevation. While inflow via snow runoff and storms are anticipated to lift lake levels, reports from federal forecasts show levels will likely be lower than last year.
Each month the United States Bureau of Reclamation releases projections forecasting Lake Powell water levels over the next 24-months. Using models the agency calculates what the minimum, most probable, and maximum inflow into the lake may be
The March 2022 forecast show the most probable scenario would see Lake Powell levels rise by about 20 feet from now through June peaking at 3,545 (15 feet lower than last year) with a continuous drop of elevation starting in July and going through March of 2023 when the levels are forecasted to be 20 feet lower than today.
That most probable inflow scenario reflects conditions which, statistically, would be exceeded 50% of the time. Meaning the forecast is just that, a forward-looking projection for the lake.
The March 2022 study shows that maximum inflow into the lake would see the lake rise to around 3,575 feet in June 2022 and up to 3,610 feet elevation in July 2024. According to the study water levels would exceed this mark just 10-percent of the time.
A minimum inflow into the lake would see an elevation at around 3,500 feet in March 2023 and a drop below 3,490 feet in March 2024. According to the 24-month study water levels would meet or exceed this mark 90-percent of the time.
The 3,490 feet elevation is significant as that level is the minimum level required to generate hydropower at the Glen Canyon Dam.
The Glen Canyon Powerplant produces around five billion kilowatt-hours of hydroelectric power annually for customers throughout the US. Among the customers for the power include the Navajo Tribal Utility Authority (NTUA) and the Utah Associated Municipal Power Systems (UAMPS).
Both utility companies serve San Juan County with NTUA providing power to the Navajo Nation in Utah and Blanding City being a member of UAMPS.
While it is unknown exactly how much of Blanding’s power today comes from the Glen Canyon Powerplant, an August 2020 report by the city noted that 9-percent of its power came from the hydroelectric project in Page, Arizona.
The city presentation also noted that because of federal subsidies the Glen Canyon Powerplant comes at a price less than half as expensive as wind and coal projects also in the city portfolio as reported in August 2020.
Meanwhile, NTUA reports a much higher percentage of its power portfolio is supplied by the Glen Canyon Dam, about 42-percent.
When asked about what an eventual drop below the minimum pool to generate hydro-power at the dam would mean for users, NTUA Deputy General Manager Srinivasa Venigalla said potentially higher cost of electricity for NTUA customers.
Preventing the Lake from reaching that low level has been the focus of federal agencies and the four western states that make up the Upper Colorado River Commission.
The Bureau of Reclamation along with the Upper Colorado Basin states of Utah, Colorado, New Mexico, and Wyoming developed and are now implementing a 2019 Drought Contingency Plan.
Part of that plan has included releasing additional water from upstream projects to reduce the risk of Lake Powell reaching critical elevations below the identified target of 3,525 feet.
From July 2021 through October 2021 an additional 161 thousand acre-feet of water from Blue Mesa Reservoir in Colorado and Flaming Gorge Reservoir in Wyoming and Utah was released to Lake Powell.
Another measure included temporarily reducing monthly releases from Glen Canyon Dam in order to hold back 350 thousand acre-feet of water in Lake Powell from January 2022 through April 2022 for release later in the year.
The bureau reports the two actions prevented Lake Powell from dropping significantly below the target elevation of 3,525 feet during the spring of 2022.
“Reclamation is not planning to take further action to address this temporary dip below 3,525 feet because the spring runoff will resolve the deficit in the short term,” said Reclamation Upper Colorado Basin Regional Director Wayne Pullan in a March news release. “However, our work is not done. Lake Powell is projected to drop below elevation 3,525 feet again later this year. Reclamation and the Upper Division States continue to collaborate with stakeholders and partners to develop and implement additional actions later this year if appropriate.”
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