GCDAMP Technical Work 

Group

Basin Hydrology, Operations and 

Water Quality

June 15, 2022

1
Upper Basin Storage (as of June 12, 2022)

Reservoir

Percent 

Current 

Live 

Storage

Current 

Live 

Storage

(maf)

Live 

Storage 

Capacity 

(maf)

Elevation

(feet)

Fontenelle 61 0.21 0.33 6,487.97 

Flaming 

Gorge 75 2.75 3.67 6,015.09

Blue Mesa 45 0.37 0.83 7,460.65 

Navajo 57 0.95 1.70 6,028.60

Lake Powell 27 6.64 24.32 3,536.20 

UC System 

Storage 35 11.04 30.94

2
Flaming Gorge and Yampa River SWE

3

FG June April-July Forecast = 520 kaf (54% of avg) Yampa June April-July Forecast = 880 kaf (74% of avg)
Upper Colorado SWE and Observed Inflows

4

https://waterwatch.usgs.gov/index.php
5

Precipitation and Temperature Outlook
6
Most Probable Jun

Water Year 

April – July 2022 

Forecasted Unregulated Inflow 

as of June 2, 2022 

Reservoir 

Unregulated 

Inflow 

(kaf) 

Percent 

of Avg 

Fontenelle 435 59 

Flaming Gorge 520 54 

Blue Mesa 430 68 

Navajo 310 49 

Powell 3,500 55 

Fla

7 Averages are based on the 1991 through 2020 period of record. 
Upper Colorado Basin

Projected Operations 

for Water Year 2022 

and 2023 Based on 

June 2022 Modeling

8
Upper Basin Drought Response Actions

9

• The Bureau of Reclamation announced on May 3, 2022, two separate urgent drought response 

actions that will help prop up Lake Powell by nearly 1 million acre-feet (maf) of water over the next 

12 months (May 2022 through April 2023). To protect Lake Powell, more water will flow into the lake 

from upstream reservoirs and less water will be released downstream:

• Under a Drought Contingency Plan adopted in 2022, approximately 500 thousand acre-feet (kaf) of water 

will come from Flaming Gorge Reservoir, located approximately 455 river miles upstream of Lake Powell 

(2022 Plan). 

• For more information: https://www.usbr.gov/uc/DocLibrary/Plans/20220429-2022DroughtResponseOperationsPlan-ApprovalMemo508-DOI.pdf. 

• Another 480 kaf will be left in Lake Powell by reducing Glen Canyon Dam’s annual release volume from 

7.48 maf to 7.00 maf (GC Operational Adjustment), in accordance with Sections 6 and 7.D of the 2007 

Interim Guidelines.

• For more information: https://www.usbr.gov/uc/DocLibrary/Plans/20220503-2022DROA-GlenCanyonDamOperationsDecisionLetter508-DOI.pdf
June 2022 24MS 2022 Plan Operations

10

Flaming Gorge Operations Lake Powell Operations
11
12
13

Placeholder schedule for 

modeling purposes. Release 

pattern subject to change. 
End of Water Year 2022 Projections

June 2022 24-Month Study Most Probable Inflow Scenario1, 2

Based on a Lake Powell Unregulated Inflow Forecast of 5.61 maf (58% of average)

Lake Powell 3,700 24.3 maf

Not to Scale

18.5 maf 3,660

1.9 

maf Dead Storage

0.0 maf 3,370

5.9 maf 3,525

3,525.79 feet

5.98 maf in storage

25% of capacity

7.00 maf

9.5 maf 3,575

1 WY 2022 unregulated inflow into Lake Powell is based on the CBRFC forecast dated 6/3/22.

2 The teacup diagram displays projected “physical” elevations and storages for Lake Powell and Lake Mead. 

1,219.6 Lake Mead 26.1 maf

9.6 maf

1,145

1,075

2.5 

maf Dead Storage

895 0.0 maf

1,090 10.9 maf

1,025 6.0 maf 1,037.23 feet

6.79 maf in storage

26% of capacity 

16.2 maf

15
End of Calendar Year 2022 Projections

June 2022 24-Month Study Most Probable Inflow Scenario1, 2

Based on a Lake Powell release of 7.00 maf in WY 2022 and 7.05 maf in WY 2023

Lake Powell 3,700 24.3 maf

Not to Scale

18.5 maf 3,660

1.9 

maf Dead Storage

0.0 maf 3,370

5.9 maf 3,525

3,519.66 feet

5.60 maf in storage

23% of capacity

9.5 maf 3,575

1 WY 2022 & WY 2023 unregulated inflow into Lake Powell is based on the CBRFC forecast dated 6/3/22.

2 The teacup diagram displays projected “physical” elevations and storages for Lake Powell and Lake Mead. The operating determinations for upcoming years, however, will be 

determined by projected “effective” elevations. Based on June 2022 24-Month Study modeling, the effective elevations for end of calendar year 2022 for Lake Powell is 3,511.37 feet 

and 1,045.95 feet for Lake Mead.

1,219.6 Lake Mead 26.1 maf

9.6 maf

1,145

1,075

2.5 

maf Dead Storage

895 0.0 maf

1,090 10.9 maf

1,025 6.0 maf 1,039.06 feet

6.97 maf in storage

26% of capacity 

16.2 maf

16
End of Calendar Year 2022 Projections: 

Effective and Tier Determination Elevations

June 2022 24-Month Study Most Probable Inflow Scenario1

Based on a Lake Powell release of 7.00 maf in WY 2022 and 7.05 maf in WY 2023

Lake Powell 3,700 24.3 maf

Not to Scale

18.5 maf 3,660

1.9 

maf Dead Storage

0.0 maf 3,370

5.9 maf 3,525

3,504.35 feet

9.5 maf 3,575

1 WY 2022 & WY 2023 unregulated inflow into Lake Powell is based on the CBRFC forecast dated 6/3/22.

1,219.6 Lake Mead 26.1 maf

9.6 maf

1,145

1,075

2.5 

maf Dead Storage

895 0.0 maf

1,090 10.9 maf

1,025 6.0 maf 1,045.95 feet

16.2 maf

17

3,511.37 feet Lake Mead

For Lake Mead, the 

effective and tier 

determination 

elevations are the 

same.

Lake Powell

The projected end of 

calendar year elevation 

used to set the following 

year’s operating tier 

appears in purple. 

The projected effective 

end of calendar year 2022 

elevation after the 

operating tier is set and 

the annual release volume 

is revised appears in blue.
End of Calendar Year 2022 Lake Powell and 

Lake Mead Elevations1,2

Physical Elevations: Real-time or projected 

elevations based on a 7.00 maf release from Lake 

Powell in WY 2022 and 7.05 maf in WY 2023.

Reservoir End of Calendar Year 2022

Physical Elevation 

Lake Powell 3,519.66

Lake Mead 1,039.06

Powell Tier Determination: Projected elevation 

“as if” the additional 0.48 maf were released from 

Powell in WY 2022 and with an 8.23 maf WY 

2023 Powell release.

Reservoir End of Calendar Year 2022

Powell Tier Determination Elevation 

Lake Powell 3,504.35

Lake Mead NA

Effective Elevation & Mead Operating Condition 

Determination: Projected elevation “as if” the additional 

0.48 maf were released from Powell in WY 2022, with an 

adjusted WY 2023 Powell release of 7.05 maf.

Reservoir End of Calendar Year 2022

Effective Elevation

Lake Powell 3,511.37

Lake Mead 1,045.95

1 For more information: https://www.usbr.gov/uc/DocLibrary/Plans/20220503-2022DROA-GlenCanyonDamOperationsDecisionLetter-508-DOI.pdf. 2 Both the Powell Tier Determination and Effective Elevations are “as if” the additional 0.48 maf were released from Powell in WY 2022. Powell’s Tier Determination elevation is used to set 

the WY 2023 operating tier. For Mead, the Effective Elevation is used to set the CY 2023 operating condition. The Department of Interior and Reclamation will work with the Basin States to 

18 determine the manner in which to operate Glen Canyon Dam to ensure the benefits of these actions are preserved. 
19

The chart above displays projected “physical” elevations for Lake Powell. The operating determination for upcoming years, however, will be 

based on a projected “tier” elevation in the August 2022 24-Month Study. Based on June 2022 24-Month Study modeling, Lake Powell’s 

operating condition for water year 2023 is projected to be within the Lower Elevation Balancing Tier. The Department of Interior and 

Reclamation will work with the Basin States to determine the manner in which to operate Glen Canyon Dam to ensure the benefits of the 

drought actions are preserved. 
Lake Mead End of Month Elevations1

Projections from the June 2022 24-Month Study Inflow Scenarios

Most Probable End of CY 2022 Projection: 

1,039.06 feet (26% full)

Min/Max Range: 1,037.63 to 1,046.32 feet Most Probable End of CY 2023 Projection: 

1,019.94 feet (22% full)

Min/Max Range: 1,011.05 to 1,041.80 feet

20

The chart above displays projected “physical” elevations for Lake Mead. The operating determination for upcoming years, however, will be 

based on a projected “effective” elevation in the August 2022 24-Month Study. Based on June 2022 24-Month Study modeling, Lake Mead’s 

operating condition for calendar year 2023 is projected to be within the 1,045 – 1,050 elevation band.
Upper Colorado Basin

Hydropower 

Maintenance

21
Glen Canyon Dam Power Plant Unit Outage Schedule for 2022

22
Glen Canyon Dam Power Plant Unit Outage Schedule for 2023

23
24



Water Quality

28


Questions?

31