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

Lake Powell Water Supply Outlook, March 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-July145 170 195 76 220 255
Pine Ck
Fremont Lk, Abv April-July50 57 70 69 77 95
New Fork
Big Piney, Nr April-July115 150 185 52 230 320
Green
Fontenelle Reservoir, Fontenelle, Nr April-July280 350 450 61 530 725
Big Sandy
Farson, Nr April-July18 22 28 56 34 50
Green
Green River, Wy, Nr April-July270 340 440 60 530 725
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July20 24 28 54 42 50
Viva Naughton Reservoir April-July23 29 34 47 54 70
Blacks Fork
Robertson, Nr April-July50 58 64 73 83 100
Ef Smiths Fork
Stateline Reservoir, Robertson,nr April-July16 19 21 75 26 31
Green
Flaming Gorge Reservoir April-July340 450 540 56 730 970


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-July19 21 23 85 26 30
Steamboat Springs April-July135 170 195 75 235 265
Elk
Milner, Nr April-July220 260 290 88 330 380
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July48 57 67 94 77 95
Yampa
Maybell, Nr April-July520 635 720 78 830 1000
Little Snake
Slater, Nr April-July80 100 125 81 147 180
Dixon, Nr April-July150 190 235 71 280 375
Lily, Nr April-July160 200 250 77 300 400
Yampa
Deerlodge Park April-July675 840 965 81 1100 1350
White
Meeker, Nr April-July155 180 205 79 230 310
Watson, Nr April-July150 180 210 78 235 330


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 10.5 14 71 16.5 21
Ashley Ck
Vernal, Nr April-July20 24 33 72 40 51
West Fork Duchesne
Vat Diversion, Blo April-July9 11 13 76 15 17.5
Duchesne
Tabiona, Nr April-July65 70 78 76 90 105
Rock Ck
Upper Stillwater Reservoir April-July48 55 65 90 72 90
South Fork Rock Ck
Docs Div, Blo April-July3.8 4.7 5.5 75 6.5 8
Rock Ck
Mountain Home, Nr April-July58 65 77 89 85 107
Currant Ck
Currant Ck Reservoir April-July11 13.5 16 90 19 23
Strawberry
Strawberry Reservoir, Soldier Springs April-July23 27 35 58 42 63
Starvation Reservoir, Duchesne, Nr April-July40 50 65 69 80 115
Duchesne
Duchesne, Nr, Knight Div, Abv April-July120 130 155 82 175 205
Lake Fork
Moon Lake Reservoir, Mtn Home, Nr April-July35 43 55 86 60 75
Yellowstone
Altonah, Nr April-July35 45 55 92 62 75
Whiterocks
Whiterocks, Nr April-July29 34 44 86 52 65
Uinta
Neola, Nr April-July40 48 62 86 72 90
Duchesne
Myton April-July140 165 220 72 260 350
Randlett, Nr April-July155 180 240 69 285 400


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-July5 7 8.5 67 10 16.5
Fish Ck
Scofield, Nr, Reservoir, Abv April-July15.5 18 21 81 24 34
Price
Scofield Reservoir, Scofield, Nr April-July19 22 27 79 31 45
Green
Green River, Ut April-July1380 1720 1900 68 2600 2900
Huntington Ck
Electric Lake April-July7 8.4 10 88 11.2 16
Power Plant, Blo April-July30 33 36 90 40 51
Seeley Ck
Joes Vly Reservoir, Orangeville, Nr April-July30 35 38 75 44 58
Ferron Ck
Ferron, Nr April-July19 23 26 74 31 43
Muddy Ck
Emery, Nr April-July9 11 12 66 13.2 21


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-July160 190 210 93 230 255
Willow Ck
Willow Ck Reservoir, Granby, Nr April-July30 40 50 100 60 72
Fraser
Winter Park April-July13 15 17 91 19 21
Williams Fork
Williams Fork Reservoir, Parshall April-July55 65 75 78 85 100
Muddy Ck
Wolford Mountain Reservoir April-July20 27 36 69 44 55
Blue
Dillon Reservoir April-July105 125 140 84 160 180
Green Mtn Reservoir April-July180 220 245 88 270 320
Colorado
Kremmling, Nr April-July550 660 760 87 860 1000
Eagle
Gypsum, Blo April-July190 240 275 82 315 375
Colorado
Dotsero, Nr April-July900 1050 1200 86 1350 1600
Frying Pan
Ruedi Reservoir, Basalt, Nr April-July85 110 130 96 145 165
Roaring Fork
Glenwood Springs April-July470 540 600 92 660 770
Colorado
Glenwood Springs, Blo April-July1400 1600 1820 88 2000 2450
Cameo, Nr April-July1550 1800 2000 88 2300 2700
Cisco, Nr April-July2550 3000 3400 83 3800 4700
Lake Powell, Glen Cyn Dam, At April-July3100 3800 4400 69 5100 7000


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 85 96 102 102 116
Almont April-July120 131 147 100 155 175
East
Almont April-July140 160 181 102 192 220
Gunnison
Gunnison, Nr April-July270 305 345 99 375 430
Tomichi Ck
Gunnison April-July28 38 47 70 54 76
Lake Fork
Gateview April-July72 85 93 79 103 135
Gunnison
Blue Mesa Reservoir April-July440 505 560 88 615 750
Morrow Point Reservoir April-July470 535 595 86 655 815
Crystal Reservoir April-July510 580 650 84 725 920
Muddy Ck
Paonia Reservoir, Bardine, Nr April-July50 60 70 86 79 97
Nf Gunnison
Somerset, Nr April-July180 205 230 87 250 290
Surface Ck
Cedaredge April-July10 12.6 15.3 105 17.1 20
Uncompahgre
Ridgway Reservoir April-July54 64 72 78 77 98
Colona April-July62 75 85 71 95 131
Delta April-July27 45 58 53 70 105
Gunnison
Grand Junction, Nr April-July860 980 1100 83 1180 1520


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 125 150 70 178 245
Mcphee Reservoir April-July110 143 168 66 197 285
San Miguel
Placerville, Nr April-July53 70 81 70 90 110
Dolores
Cisco, Nr April-July185 250 300 59 345 500


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 136 160 82 182 230
Carracas, Nr April-July191 230 270 82 305 385
Navajo Reservoir, Archuleta, Nr April-July315 380 455 72 520 680
Bluff, Nr April-July500 615 750 68 835 1030
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July29 35 40 82 46 54
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July35 42 48 83 55 67
Little Navajo
Oso Div Dam,bl,chromo,nr April-July2.4 2.9 3.6 59 4.6 5.6
Piedra
Arboles, Nr April-July86 103 123 68 138 175
Los Pinos
Vallecito Reservoir, Bayfield, Nr April-July109 129 142 80 161 198
Animas
Durango April-July230 265 305 79 350 430
Florida
Lemon Reservoir, Durango, Nr April-July24 30 36 75 42 53
La Plata
Hesperus April-July11.5 12.8 16.4 71 18.1 24
Mancos
Mancos, Nr April-July7.1 9.8 13.3 77 15.3 20

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 156.6 114 47 131.6 96 137.0 334.0
untitled Big Sandy
Big Sandy Reservoir, Nr Farson 6.8 40 18 8.1 48 17.0 38.3
Blacks Fork
Meeks Cabin 11.4 93 38 5.0 41 12.3 29.9
untitled Ef Smiths Fork
Stateline Reservoir, Robertson,nr 5.7 104 41 3.8 70 5.4 13.9
untitled Green
Flaming Gorge Reservoir 2905.8 95 78 3145.1 103 3062.9 3749.0
untitled Strawberry
Strawberry Reservoir, Soldier Springs 833.4 103 75 925.0 114 811.8 1105.9
Starvation Reservoir, Duchesne, Nr 141.3 97 85 152.3 104 146.0 165.3
untitled Rock Ck
Upper Stillwater Reservoir 9.3 101 30 4.7 51 9.3 31.4
untitled Lake Fork
Moon Lake Reservoir, Mtn Home, Nr 25.4 119 69 13.1 62 21.3 36.5
untitled Big Brush Ck
Red Fleet Reservoir, Vernal, Nr 11.0 61 43 16.1 89 18.2 25.7
untitled Price
Scofield Reservoir, Scofield, Nr 19.0 72 29 34.4 130 26.5 65.8
untitled Seeley Ck
Joes Vly Reservoir, Orangeville, Nr 21.9 57 35 38.2 99 38.6 62.5
untitled Huntington Ck
Electric Lake 10.7 62 34 19.0 109 17.3 31.5
untitled
TOTAL 4158.2 96 73 4496.4 104 4323.5 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 313.2 90 64 381.0 110 346.4 490.3
untitled Willow Ck
Willow Ck Reservoir, Granby, Nr 7.9 92 87 7.7 90 8.6 9.1
untitled Williams Fork
Williams Fork Reservoir, Parshall 59.7 89 62 67.1 100 67.2 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 30.4 68 46 53.0 118 44.8 66.0
untitled Blue
Dillon Reservoir 196.3 89 77 203.9 92 220.7 254.0
Green Mtn Reservoir 57.1 80 39 69.8 98 71.1 146.9
untitled Homestake Ck
Homestake Reservoir 28.7 93 67 23.5 76 31.0 43.0
untitled Frying Pan
Ruedi Reservoir, Basalt, Nr 55.8 83 55 58.7 87 67.4 102.0
untitled Plateau Ck
Vega Reservoir, Collbran, Nr 5.9 44 18 5.7 43 13.2 32.9
untitled Taylor
Taylor Park Reservoir 57.7 86 54 63.7 95 67.2 106.2
untitled Gunnison
Blue Mesa Reservoir 241.0 48 29 400.9 80 499.4 827.9
Morrow Point Reservoir 105.5 97 90 106.3 97 109.1 117.0
Crystal Reservoir 15.1 97 86 15.8 101 15.6 17.5
untitled Muddy Ck
Paonia Reservoir, Bardine, Nr 1.3 43 8 2.2 74 3.0 16.7
untitled Uncompahgre
Ridgway Reservoir 65.4 96 79 53.7 79 67.9 83.0
untitled Dolores
Mcphee Reservoir 168.4 65 44 167.3 65 257.8 381.1
untitled
TOTAL 1409.3 75 51 1680.3 89 1890.3 2790.6
Colorado
Lake Powell 6100.0 43 25 9225.6 65 14153.2 24322.0
untitled
TOTAL 6100.0 43 25 9225.6 65 14153.2 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 41.5 61 33 40.7 59 68.5 125.4
untitled San Juan
Navajo Reservoir, Archuleta, Nr 848.5 67 50 1051.9 83 1273.3 1696.0
untitled Florida
Lemon Reservoir, Durango, Nr 13.3 73 33 10.8 59 18.2 39.8
untitled
TOTAL 903.3 66 49 1103.4 81 1360.0 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