New 1991-2020 Averages being used this year.
Lake Powell Water Supply Outlook, February 1, 2022

Lake Powell Water Supply Outlook, February 1, 2022

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by Ashley Nielson
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Lake Powell Sub-Basin Summaries




*Median of forecasts within each basin.





*Median of forecasts within each basin.







*Median of forecasts within each basin.




Upper Green Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Yampa/White Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Duchesne Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Lower Green Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Upper Colorado Mainstem Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Gunnison Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Dolores Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

San Juan Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.


Upper Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Green
Daniel, Nr, Warren Bridge, At April-July165 205 240 94 265 330
Pine Ck
Fremont Lk, Abv April-July60 68 80 79 95 105
New Fork
Big Piney, Nr April-July148 195 250 70 315 365
Green
Fontenelle Reservoir, Fontenelle, Nr April-July370 500 615 84 740 930
Big Sandy
Farson, Nr April-July21 29 36 72 44 56
Green
Green River, Wy, Nr April-July360 490 605 82 775 950
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July25 30 36 69 54 62
Viva Naughton Reservoir April-July30 37 48 66 75 93
Blacks Fork
Robertson, Nr April-July57 65 77 88 93 110
Ef Smiths Fork
Stateline Reservoir, Robertson,nr April-July19 22 25 89 30 34
Green
Flaming Gorge Reservoir April-July450 600 750 78 1050 1250


Yampa/White Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Yampa
Stagecoach Rsvr, Abv April-July20 23 26 96 30 36
Steamboat Springs April-July175 200 230 88 255 320
Elk
Milner, Nr April-July275 300 355 108 380 445
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July58 70 80 113 90 110
Yampa
Maybell, Nr April-July650 750 890 97 950 1200
Little Snake
Slater, Nr April-July105 120 145 94 170 195
Dixon, Nr April-July195 235 280 85 340 410
Lily, Nr April-July190 240 285 88 370 435
Yampa
Deerlodge Park April-July840 1000 1170 98 1300 1600
White
Meeker, Nr April-July175 200 225 87 245 365
Watson, Nr April-July170 200 230 85 250 390


Duchesne Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Big Brush Ck
Vernal, Nr, Red Fleet Res, Abv April-July8.5 11.5 14.5 74 18 23
Ashley Ck
Vernal, Nr April-July20 25 36 78 42 60
West Fork Duchesne
Vat Diversion, Blo April-July10 12.5 14.5 85 17 25
Duchesne
Tabiona, Nr April-July71 80 92 89 105 130
Rock Ck
Upper Stillwater Reservoir April-July55 64 74 103 81 112
South Fork Rock Ck
Docs Div, Blo April-July4.5 5.5 6.5 89 8 10
Rock Ck
Mountain Home, Nr April-July68 77 87 100 98 135
Currant Ck
Currant Ck Reservoir April-July12.5 16 18.5 105 23 31
Strawberry
Strawberry Reservoir, Soldier Springs April-July27 35 45 75 62 82
Starvation Reservoir, Duchesne, Nr April-July55 70 85 90 120 170
Duchesne
Duchesne, Nr, Knight Div, Abv April-July135 160 175 93 200 260
Lake Fork
Moon Lake Reservoir, Mtn Home, Nr April-July45 53 60 94 67 92
Yellowstone
Altonah, Nr April-July42 55 62 103 67 91
Whiterocks
Whiterocks, Nr April-July33 38 52 102 56 77
Uinta
Neola, Nr April-July44 55 72 100 79 110
Duchesne
Myton April-July170 220 265 87 340 500
Randlett, Nr April-July180 235 290 83 360 570


Lower Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
White
Blo Tabbyune Ck, Soldier Summit, Nr April-July6 8.5 10.5 83 14 20
Fish Ck
Scofield, Nr, Reservoir, Abv April-July18 21 24 92 29 39
Price
Scofield Reservoir, Scofield, Nr April-July22 27 31 91 38 53
Green
Green River, Ut April-July1800 2100 2450 87 2900 3900
Huntington Ck
Electric Lake April-July8 9.5 11.5 102 14 18
Power Plant, Blo April-July30 34 41 103 46 57
Seeley Ck
Joes Vly Reservoir, Orangeville, Nr April-July33 40 44 86 49 64
Ferron Ck
Ferron, Nr April-July21 25 30 86 34 47
Muddy Ck
Emery, Nr April-July10.5 12 13.5 74 16 24


Upper Colorado Mainstem Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Colorado
Lake Granby, Granby, Nr April-July155 190 210 93 235 280
Willow Ck
Willow Ck Reservoir, Granby, Nr April-July30 42 52 104 64 84
Fraser
Winter Park April-July13 16.5 18.5 99 20 22
Williams Fork
Williams Fork Reservoir, Parshall April-July55 68 78 81 88 110
Muddy Ck
Wolford Mountain Reservoir April-July24 32 44 85 53 70
Blue
Dillon Reservoir April-July105 130 150 90 170 200
Green Mtn Reservoir April-July175 225 255 91 290 345
Colorado
Kremmling, Nr April-July550 680 790 91 900 1100
Eagle
Gypsum, Blo April-July190 250 285 85 330 420
Colorado
Dotsero, Nr April-July880 1120 1260 90 1420 1770
Frying Pan
Ruedi Reservoir, Basalt, Nr April-July90 115 130 96 145 175
Roaring Fork
Glenwood Springs April-July500 575 635 97 700 880
Colorado
Glenwood Springs, Blo April-July1420 1720 1920 92 2200 2700
Cameo, Nr April-July1600 1900 2100 93 2400 3050
Cisco, Nr April-July2500 3000 3400 83 4000 5200
Lake Powell, Glen Cyn Dam, At April-July3400 4300 5000 78 5800 8050


Gunnison Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Taylor
Taylor Park Reservoir April-July79 90 100 106 109 146
Almont April-July119 138 153 104 165 225
East
Almont April-July148 168 187 106 205 275
Gunnison
Gunnison, Nr April-July275 330 365 104 395 555
Tomichi Ck
Gunnison April-July30 42 50 75 60 93
Lake Fork
Gateview April-July72 81 93 79 103 136
Gunnison
Blue Mesa Reservoir April-July435 515 585 92 650 860
Morrow Point Reservoir April-July460 550 620 90 690 905
Crystal Reservoir April-July500 610 680 88 750 985
Muddy Ck
Paonia Reservoir, Bardine, Nr April-July47 60 70 86 80 122
Nf Gunnison
Somerset, Nr April-July175 215 240 91 265 370
Surface Ck
Cedaredge April-July11.5 14.8 17 116 19 25
Uncompahgre
Ridgway Reservoir April-July54 66 72 78 78 101
Colona April-July62 76 85 71 95 133
Delta April-July27 45 58 53 70 105
Gunnison
Grand Junction, Nr April-July830 1000 1130 85 1250 1750


Dolores Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Dolores
Dolores April-July99 135 160 74 194 260
Mcphee Reservoir April-July110 151 185 73 225 310
San Miguel
Placerville, Nr April-July55 75 86 75 98 127
Dolores
Cisco, Nr April-July190 270 340 67 410 590


San Juan Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
San Juan
Pagosa Springs April-July115 142 163 84 192 230
Carracas, Nr April-July190 235 280 85 320 390
Navajo Reservoir, Archuleta, Nr April-July310 395 455 72 525 680
Bluff, Nr April-July475 620 775 70 865 1030
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July29 35 40 82 47 58
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July35 42 48 83 57 72
Little Navajo
Oso Div Dam,bl,chromo,nr April-July2.4 3.1 3.8 62 4.6 7.5
Piedra
Arboles, Nr April-July82 102 123 68 138 180
Los Pinos
Vallecito Reservoir, Bayfield, Nr April-July108 129 142 80 156 200
Animas
Durango April-July225 270 305 79 345 430
Florida
Lemon Reservoir, Durango, Nr April-July24 30 36 75 43 54
La Plata
Hesperus April-July11 13.7 16.4 71 19.3 26
Mancos
Mancos, Nr April-July6.9 10.5 13.3 77 15.7 24

Differences between the full period forecasts and the residual forecasts may not exactly equal the actual observed volumes due to rounding conventions (see Definitions section).

Green End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Green
Fontenelle Reservoir, Fontenelle, Nr 180.2 109 54 153.5 93 165.5 334.0
untitled Big Sandy
Big Sandy Reservoir, Nr Farson 6.5 38 17 7.9 47 16.9 38.3
Blacks Fork
Meeks Cabin 10.5 92 35 4.2 37 11.4 29.9
untitled Ef Smiths Fork
Stateline Reservoir, Robertson,nr 5.5 100 39 3.7 68 5.5 13.9
untitled Green
Flaming Gorge Reservoir 2900.9 94 77 3151.0 102 3081.2 3749.0
untitled Strawberry
Strawberry Reservoir, Soldier Springs 829.2 102 75 920.0 113 811.3 1105.9
Starvation Reservoir, Duchesne, Nr 133.7 96 81 143.9 103 139.7 165.3
untitled Rock Ck
Upper Stillwater Reservoir 13.3 131 42 9.1 90 10.1 31.4
untitled Lake Fork
Moon Lake Reservoir, Mtn Home, Nr 23.8 120 65 12.1 61 19.9 36.5
untitled Big Brush Ck
Red Fleet Reservoir, Vernal, Nr 10.6 60 41 15.8 89 17.7 25.7
untitled Price
Scofield Reservoir, Scofield, Nr 17.8 70 27 32.8 128 25.6 65.8
untitled Seeley Ck
Joes Vly Reservoir, Orangeville, Nr 21.5 56 34 38.4 100 38.5 62.5
untitled Huntington Ck
Electric Lake 11.1 63 35 19.3 109 17.6 31.5
untitled
TOTAL 4164.5 95 73 4511.7 103 4360.8 5689.6


Upper Colorado End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Colorado
Lake Granby, Granby, Nr 340.5 93 69 407.3 111 367.8 490.3
untitled Willow Ck
Willow Ck Reservoir, Granby, Nr 7.5 91 83 7.5 91 8.3 9.1
untitled Williams Fork
Williams Fork Reservoir, Parshall 60.5 88 62 69.3 101 68.4 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 30.9 68 47 53.5 118 45.1 66.0
untitled Blue
Dillon Reservoir 196.3 88 77 210.3 94 224.2 254.0
Green Mtn Reservoir 59.6 78 41 72.2 94 76.5 146.9
untitled Homestake Ck
Homestake Reservoir 28.8 90 67 40.3 126 31.8 43.0
untitled Frying Pan
Ruedi Reservoir, Basalt, Nr 57.7 82 57 60.2 85 70.8 102.0
untitled Plateau Ck
Vega Reservoir, Collbran, Nr 5.7 45 17 5.3 42 12.6 32.9
untitled Taylor
Taylor Park Reservoir 58.3 86 55 65.1 96 68.1 106.2
untitled Gunnison
Blue Mesa Reservoir 236.4 46 29 400.1 78 515.2 827.9
Morrow Point Reservoir 104.5 95 89 105.8 96 109.9 117.0
Crystal Reservoir 16.2 108 92 15.6 104 15.0 17.5
untitled Muddy Ck
Paonia Reservoir, Bardine, Nr 0.5 21 3 1.7 67 2.6 16.7
untitled Uncompahgre
Ridgway Reservoir 65.1 96 78 53.2 79 67.5 83.0
untitled Dolores
Mcphee Reservoir 166.7 65 44 167.9 66 256.3 381.1
untitled
TOTAL 1435.3 74 51 1735.3 89 1940.2 2790.6
Colorado
Lake Powell 6335.2 44 26 9638.5 67 14430.3 24322.0
untitled
TOTAL 6335.2 44 26 9638.5 67 14430.3 24322.0


San Juan End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Los Pinos
Vallecito Reservoir, Bayfield, Nr 38.6 56 31 38.4 56 68.5 125.4
untitled San Juan
Navajo Reservoir, Archuleta, Nr 859.1 67 51 1064.6 83 1277.0 1696.0
untitled Florida
Lemon Reservoir, Durango, Nr 13.2 73 33 10.7 59 18.1 39.8
untitled
TOTAL 910.9 67 49 1113.7 82 1363.6 1861.2

Precipitation Maps




Definitions

10% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 10% chance of being exceeded. Previously referred to as "Reasonable Maximum Forecast".

50% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 50% chance of being exceeded. Previously referred to as "Most Probable Forecast".

90% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 90% chance of being exceeded. Previously referred to as "Reasonable Minimum Forecast".

Acre-Foot (af): The volume equal to one acre covered one foot deep (43,560 cubic feet). See kaf below.

Average: The arithmetic mean. The sum of the values divided by the number of values. Values from 1991-2020 are used for this publication.

Categories: Much Above Average=Greater than 130%, Above Average=111-130%, Near Average=90-110%, Below Average=70-89%, Much Below Average=Less than 70%.

CBRFC: Colorado Basin River Forecast Center.

Forecast Period: The period from April 1 through July 31, unless otherwise noted.

kaf: Thousand Acre-Feet. See Acre-Foot above.

Inflow: The volume of water that flows into a reservoir or lake.

Median: The middle value of an ordered set of values. Half of the values are higher and half of the values are lower. When the set contains an even number of values the median is the average of the two middle numbers.

NOAA: National Oceanic and Atomospheric Administration.

NWS: National Weather Service.

Rounding Conventions:
RangeRound to
0-1.990.01
2.0-19.90.1
20-1991.0
200-9995.0
1000+3 significant digits


Streamflow: The volume of water that flows past a specific stream site.

Water Year: The 12-month period, October 1 through September 30. The water year is designated by the calendar year in which it ends. Thus, the year ending September 30, 2008, is called the "2008 water year."


Additional Information

Water supply forecasts take into consideration present hydrometeorological conditions and use average basin temperatures and precipitation for the forecast period. As the forecast season progresses, a greater portion of the future hydrologic and climatic uncertainty becomes known and monthly forecasts become more accurate. For more information on the tools we use, consult Water Supply Forecasting Tools.

Volume forecasts represent adjusted flows; that is, observed flows with upstream water use taken into account. Adjusted flows will closely approximate natural or unimpaired flows. However, not all upstream diversions or impoundments are measured or quantifiable. For specific adjustments used with each forecast point, consult the Guide to Water Supply Forecasting.

The Water Supply Outlook is issued monthly January through May by the Colorado Basin River Forecast Center. It represents a coordinated effort between the National Weather Service, Natural Resources Conservation Service, Bureau of Reclamation, U.S. Geological Survey and local water district managers.

Note: Data used in this report are provisional and are subject to revision.

For more information, or to be included on the mailing list, please contact:

Colorado Basin River Forecast Center
2242 W North Temple
Salt Lake City, UT 84116
(801) 524-5130
www.cbrfc.noaa.gov