Glen Canyon AMP Technical 

Working Group 

Basin Hydrology and Operations 

January 25, 2024 

1 
Upper Basin Storage (as of January 23, 2024) 

Reservoir 

Percent 

Current 

Live 

Storage 

Current 

Live 

Storage 

(maf) 

Live 

Storage 

Capacity 

(maf) 

Elevation 

(feet) 

Fontenelle 52 0.17 0.33 6,482.90 

Flaming 

Gorge 86 3.14 3.67 6,026.59 

Blue Mesa 69 0.57 0.83 7,489.25 

Navajo 66 1.09 1.65 6,042.76 

Lake Powell 35 8.20 23.31 3,565.71 

UC System 

Storage 44 13.30 29.93 

Total System 

Storage 42 24.84 58.48 

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3 
Weather Prediction Center and Climate 

Prediction Center Precipitation Forecasts 

4 
Upper Colorado SWE and Observed Inflows 

https://www.nrcs.usda.gov/Internet/WCIS/AWS_PLOTS/basinCharts/Proj/WTEQ/assocH 

UC2/14_Upper_Colorado_Region.html 

https://waterwatch.usgs.gov/index.php 

5 
 

 

 

Forecast Development 

April 1 

January 1 

January 1st Forecast 

• What we know: 

• About 40% snowpack 

accumulation 

• Fall Soil Moisture 

conditions 

• What we don’t know: 

• Jan-May weather 

• About 60% of the 

snowpack accumulation 

April 1st Forecast 

• What we know: 

• About 98% of the 

snowpack accumulation 

• Dec-March weather 

• What we don’t know: 

• April-May weather 

• Snowmelt pattern 

6
 

 

 

Most Probable January Forecast

Water Year 2024 

April – July 2024 

Forecasted Unregulated Inflow 

as of January 4, 2024 

Reservoir Inflow 

(kaf) 

Change 

from 

Dec 

Percent 

of Avg1 

Fontenelle 535 -80 73 

Flaming Gorge 675 -130 70 

Blue Mesa 490 -45 77 

Navajo 375 -62 60 

Powell 4,200 -600 66 

January midmonth = 4,700 kaf (74% of avg) 

Water Year 2024 

Unregulated Inflow Forecast 

as of January 4, 2024 

Reservoir Inflow 

(kaf) 

Change 

from 

Dec 

Percent 

of Avg1 

Fontenelle 878 -83 82 

Flaming Gorge 1,155 -134 82 

Blue Mesa 728 -49 81 

Navajo 536 -64 59 

Powell 6,918 -701 72 

January midmonth = 7,418 kaf (77% of avg) 

1

Averages are based on the 1991 through 2020 period of record. 

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8 
 

Upper Colorado Basin 

Hydrology and Operations 

Projections Based on January 

2024 24-Month Study 

9 
 

 

 

 

 

 

Upper Basin Reservoir Operations 

Water Years 2024 and 2025 

• Lake Powell will be operated consistent with the 2007 Interim Guidelines, the Upper Basin 

Drought Response Operations Agreement and Upper Basin Records of Decision 

• Lake Powell WY 2024 will operate in the Mid-Elevation Release Tier where Lake Powell will 

release 7.48 maf 

• Reclamation will also ensure all appropriate consultation with Basin Tribes, the Republic of 

Mexico, other federal agencies, water users and non-governmental organizations with respect 

to implementation of these monthly and annual operations. 

10 
 

 

DROA Recovery - BM 

• November 2023 recovery amount 

0 AF 

• December 2023 recovery amount 

of 13 kaf 

• Incremental Recovery at Blue 

Mesa COMPLETED by midnight

12/29. 

• Icing target ACHIEVED at 7490.05’ 

on midnight 12/31. 

11 
 

 

 

 

DROA Recovery - FG 

• November 2023 recovery amount 

46 kaf at Flaming Gorge. 

• December 2023 recovery amount 

of 50.3 kaf 

• Projected to achieve incremental 

recovery in February 2024 and the

May 1 Drawdown Target of 6,027 

(mod-dry target) 

12 
 

 

 

 

 

 

 

Drought Response Operations Agreement (DROA) 

Completed DROA Volumes1,2 

Reservoir 

2021 

DROA 

Volume 

(kaf) 

2022 

DROA 

Volume 

(kaf) 

2023 

DROA 

Volume 

(kaf)4 

Total 

DROA 

Volume 

(kaf) 

Flaming 

Gorge 125 3283 -358 95 

Blue Mesa 36 0 -36 0 

Navajo 0 0 0 0 

Total DROA 

Volume 

(kaf) 

161 328 -394 95 

1

DROA operational year is from May through April. 

2Positive values indicate Drought Response Operations Releases and negative 

values indicate Drought Response Operations Recovery 

3 463 kaf of DROA releases prior to DROA release suspension on March 6, 2023. 

-135 kaf of DROA recovery from March 7, 2023 through April 30, 2023 

13 4DROA volumes through September 2023 
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Reclamation Operational Modeling

Model Comparison 

Colorado River Mid-term Modeling System (CRMMS) 

24 CRSS -Month Study Mode 

(Manual Mode) 

Ensemble Mode 

(Rule-based Mode) 

Primary Use 

AOP tier determinations and 

projections of current 

conditions 

Risk-based operational planning 

and analysis 

Long-term planning, comparison of 

alternatives 

Simulated Reservoir 

Operations Operations input manually Rule-driven operations 

Probabilistic or 

Deterministic 

Deterministic – single 

hydrologic trace 

Deterministic OR 

Probabilistic 30 (or more) 

hydrologic traces 

Probabilistic – 100+ traces 

Time Horizon (years) 1 - 2 1 - 5 1 - 50 

Upper Basin Inflow Unregulated forecast, 1 trace Unregulated ESP forecast, 30 traces Natural flow; historical, paleo, or 

climate change hydrology 

Upper Basin Demands Implicit, in unregulated inflow forecast Explicit, 2016 UCRC assumptions 

Lower Basin Demands Official approved or operational Developed with LB users 

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Mead ESP

Most Probable End of CY 2025 Projection: 

1,044.33 feet (28% full) 

Min/Max Range: 1,038.56 to 1,072.08 feet 

Most Probable End of CY 2024 Projection: 

1,056.19 feet (31% full) 

Min/Max Range: 1,053.70 to 1,064.89 feet 

18 
Upper Colorado Basin 

Hydropower

Maintenance 

19 
Glen Canyon Dam Power Plant Unit Outage Schedule for 2024 

20 
Glen Canyon Dam Power Plant Unit Outage Schedule for 2025 

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24 
Questions? 

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