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

Lake Powell Water Supply Outlook, June 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-July155 164 180 71 210 230
June-July115 124 140 80 170 190
Pine Ck
Fremont Lk, Abv April-July53 57 65 64 72 79
June-July40 44 52 67 59 66
New Fork
Big Piney, Nr April-July139 148 175 49 210 240
June-July100 109 136 53 173 200
Green
Fontenelle Reservoir, Fontenelle, Nr April-July315 375 435 59 490 550
June-July200 260 320 67 375 435
Big Sandy
Farson, Nr April-July23 25 28 56 35 40
June-July13 14.9 18.4 58 25 30
Green
Green River, Wy, Nr April-July300 365 425 58 480 545
June-July190 255 315 66 370 435
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July16.4 18.5 21 40 25 30
June-July5 7.1 9.6 40 13.6 18.6
Viva Naughton Reservoir April-July28 31 35 48 39 45
June-July4 7 10.7 36 14.7 21
Blacks Fork
Robertson, Nr April-July55 59 65 74 72 79
June-July25 29 35 63 42 49
Ef Smiths Fork
Stateline Reservoir, Robertson,nr April-July17 18 20 71 22 25
June-July6.8 7.8 9.8 55 11.9 15
Green
Flaming Gorge Reservoir April-July380 455 520 54 610 705
June-July225 300 365 61 455 550


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-July7.8 9.6 11.3 42 12.5 14.3
June-July2.5 4.3 6 46 7.2 9
Steamboat Springs April-July162 182 200 77 215 240
June-July46 66 84 71 99 124
Elk
Milner, Nr April-July265 285 300 91 330 350
June-July98 119 133 81 163 183
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July36 38 39 55 41 44
June-July1 2.1 3.6 32 5.6 8.6
Yampa
Maybell, Nr April-July550 635 685 74 730 790
June-July144 230 280 74 325 385
Little Snake
Slater, Nr April-July100 108 115 74 130 140
June-July18 26 33 51 48 58
Dixon, Nr April-July174 189 205 62 230 250
June-July25 40 56 44 81 101
Lily, Nr April-July170 184 200 62 225 250
June-July25 39 55 44 80 105
Yampa
Deerlodge Park April-July700 795 880 74 950 1030
June-July155 250 335 70 405 485
White
Meeker, Nr April-July143 168 185 71 205 220
June-July45 70 87 64 107 122
Watson, Nr April-July136 159 175 65 200 220
June-July45 68 84 60 109 129


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-July9.8 10.3 11 56 12 13.5
June-July2 2.5 3.2 39 4.2 5.7
Ashley Ck
Vernal, Nr April-July24 26 28 61 32 35
June-July6.5 8.5 10.4 45 14.4 17.4
West Fork Duchesne
Vat Diversion, Blo April-July10.1 11 12 71 13 14
June-July1.5 2.4 3.4 40 4.4 5.4
Duchesne
Tabiona, Nr April-July61 70 75 73 82 88
June-July15 24 29 52 36 42
Rock Ck
Upper Stillwater Reservoir April-July51 54 60 83 65 70
June-July14 16.8 23 50 28 33
South Fork Rock Ck
Docs Div, Blo April-July3.6 4 4.7 64 5.3 6
June-July1.3 1.7 2.4 50 3 3.7
Rock Ck
Mountain Home, Nr April-July58 62 70 80 75 80
June-July17 21 29 53 34 39
Currant Ck
Currant Ck Reservoir April-July6.1 7 8 45 9 10
June-July0 0.86 1.9 27 2.9 3.9
Strawberry
Strawberry Reservoir, Soldier Springs April-July26 28 30 50 33 38
June-July0 2.5 4.5 23 7.5 12.5
Starvation Reservoir, Duchesne, Nr April-July33 34 35 37 40 53
June-July0 0.62 1.6 6 6.6 19.6
Duchesne
Duchesne, Nr, Knight Div, Abv April-July117 129 140 74 149 162
June-July32 44 55 50 64 77
Lake Fork
Moon Lake Reservoir, Mtn Home, Nr April-July36 39 45 70 48 52
June-July12 15.3 21 51 24 28
Yellowstone
Altonah, Nr April-July35 36 40 67 45 52
June-July15 16.8 20 49 25 32
Whiterocks
Whiterocks, Nr April-July23 26 30 59 32 37
June-July10 12.4 16.6 50 18.4 24
Uinta
Neola, Nr April-July28 33 40 56 43 50
June-July14 18.3 26 52 29 36
Duchesne
Myton April-July124 135 155 51 180 200
June-July7 17.8 38 24 63 83
Randlett, Nr April-July122 134 155 44 180 215
June-July4 15.5 37 20 62 97


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-July4.1 4.3 4.5 36 5 5.9
June-July0.2 0.43 0.63 23 1.1 2
Fish Ck
Scofield, Nr, Reservoir, Abv April-July13 14 16 62 17 19
June-July0.5 1.5 3.5 42 4.5 6.5
Price
Scofield Reservoir, Scofield, Nr April-July18.1 19 21 62 23 26
June-July0.5 1.4 3.4 33 5.4 8
Green
Green River, Ut April-July1230 1430 1600 57 1880 2120
June-July500 700 875 60 1150 1390
Huntington Ck
Electric Lake April-July6.4 7 7.5 66 8 9
June-July0.5 1.1 1.6 42 2.1 3.1
Power Plant, Blo April-July18.2 19.9 25 63 27 30
June-July5.2 6.9 12 57 14 17
Seeley Ck
Joes Vly Reservoir, Orangeville, Nr April-July25 29 36 71 40 43
June-July5.5 9.7 16.4 59 20 23
Ferron Ck
Ferron, Nr April-July17.8 19.6 22 63 24 26
June-July3.5 5.3 7.7 41 9.7 11.7
Muddy Ck
Emery, Nr April-July5.9 6.5 7.5 41 8 9
June-July2 2.6 3.6 33 4.1 5.1


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-July180 195 210 93 225 235
June-July93 108 122 84 138 148
Willow Ck
Willow Ck Reservoir, Granby, Nr April-July52 56 60 120 64 68
June-July1.6 5.6 9.6 46 13.6 17.6
Fraser
Winter Park April-July13 14.5 16 86 17 18
June-July7.8 9.3 10.8 81 11.8 12.8
Williams Fork
Williams Fork Reservoir, Parshall April-July66 72 78 81 83 88
June-July31 37 43 68 48 53
Muddy Ck
Wolford Mountain Reservoir April-July25 27 29 56 32 35
June-July2.1 4.1 6.5 36 9.1 12.1
Blue
Dillon Reservoir April-July113 120 128 77 135 143
June-July70 77 85 75 92 100
Green Mtn Reservoir April-July190 205 220 79 235 250
June-July109 124 139 75 154 169
Colorado
Kremmling, Nr April-July650 700 750 86 800 840
June-July285 335 385 73 435 475
Eagle
Gypsum, Blo April-July215 230 245 73 260 275
June-July109 124 138 64 154 169
Colorado
Dotsero, Nr April-July1000 1070 1140 81 1210 1280
June-July460 530 600 72 670 740
Frying Pan
Ruedi Reservoir, Basalt, Nr April-July95 103 110 81 118 125
June-July46 54 61 70 69 76
Roaring Fork
Glenwood Springs April-July460 490 520 79 550 580
June-July220 250 280 64 310 340
Colorado
Glenwood Springs, Blo April-July1500 1600 1700 82 1800 1900
June-July690 790 890 70 990 1090
Cameo, Nr April-July1600 1700 1800 79 1900 2000
June-July740 840 940 68 1040 1140
Cisco, Nr April-July2500 2700 2850 70 3050 3200
June-July905 1110 1260 57 1460 1610
Lake Powell, Glen Cyn Dam, At April-July2980 3230 3500 55 3850 4230
June-July1000 1250 1520 44 1870 2250


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-July73 77 81 86 86 93
June-July38 42 46 78 51 58
Almont April-July108 116 122 83 129 139
June-July52 60 66 73 73 83
East
Almont April-July140 147 155 88 163 175
June-July59 66 74 72 82 94
Gunnison
Gunnison, Nr April-July250 265 280 80 295 310
June-July110 129 140 68 155 173
Tomichi Ck
Gunnison April-July25 28 31 46 34 38
June-July5 7.9 11.1 33 14 18
Lake Fork
Gateview April-July57 61 65 55 69 75
June-July18 22 26 34 30 36
Gunnison
Blue Mesa Reservoir April-July385 410 430 68 450 480
June-July145 170 190 54 210 240
Morrow Point Reservoir April-July400 425 445 64 470 500
June-July150 175 195 51 220 250
Crystal Reservoir April-July430 455 475 62 500 535
June-July155 180 200 48 225 260
Muddy Ck
Paonia Reservoir, Bardine, Nr April-July45 46 49 60 52 56
June-July1.7 2.6 6 24 8.7 12.3
Nf Gunnison
Somerset, Nr April-July198 205 215 81 225 235
June-July41 48 56 53 68 78
Surface Ck
Cedaredge April-July9.8 10.4 10.7 73 11.6 12.8
June-July1.7 2.3 2.6 39 3.5 4.7
Uncompahgre
Ridgway Reservoir April-July46 50 53 58 56 61
June-July19 23 26 44 29 34
Colona April-July51 54 58 48 62 70
June-July16 19 23 32 27 35
Delta April-July25 30 35 37 40 49
June-July3 7.5 13 25 17.4 27
Gunnison
Grand Junction, Nr April-July735 770 815 61 860 920
June-July190 225 270 42 315 375


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-July116 120 128 60 134 140
June-July10 14.8 22 27 28 34
Mcphee Reservoir April-July123 129 135 53 140 149
June-July10 15.4 22 26 27 36
San Miguel
Placerville, Nr April-July51 55 59 51 62 66
June-July13 17.1 21 31 24 28
Dolores
Cisco, Nr April-July205 210 220 44 230 245
June-July20 25 32 18 41 58


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 116 123 63 129 136
June-July8.5 10.3 16.5 20 23 30
Carracas, Nr April-July182 186 198 60 205 220
June-July14 17.5 30 22 38 50
Navajo Reservoir, Archuleta, Nr April-July295 300 310 49 325 340
June-July5 9.5 20 8 34 48
Bluff, Nr April-July530 550 565 51 605 640
June-July40 61 76 16 118 150
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July28 29 31 63 32 34
June-July2 3.6 5 25 6.7 8
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July33 34 37 64 39 40
June-July3.9 5 8 31 10 11.8
Little Navajo
Oso Div Dam,bl,chromo,nr April-July2.6 2.7 2.8 46 3 3.1
June-July0.07 0.15 0.3 18 0.43 0.6
Piedra
Arboles, Nr April-July75 78 83 46 85 91
June-July4.6 7 12 19 14.7 20
Los Pinos
Vallecito Reservoir, Bayfield, Nr April-July95 98 103 58 109 115
June-July15 17.9 23 26 29 35
Animas
Durango April-July183 194 205 53 215 230
June-July36 47 58 29 66 85
Florida
Lemon Reservoir, Durango, Nr April-July24 25 27 56 29 31
June-July2.6 3.5 5.1 22 7 9
La Plata
Hesperus April-July11.3 11.7 12.2 53 12.9 13.7
June-July1.1 1.5 2 22 2.7 3.5
Mancos
Mancos, Nr April-July8.8 9.2 9.6 56 9.8 10.8
June-July0 0.4 0.8 22 0.93 2

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 158.3 83 47 151.6 79 190.9 334.0
untitled Big Sandy
Big Sandy Reservoir, Nr Farson 17.9 60 47 18.8 63 29.7 38.3
Blacks Fork
Meeks Cabin 28.4 113 95 16.6 66 25.1 29.9
untitled Ef Smiths Fork
Stateline Reservoir, Robertson,nr 12.8 122 92 8.3 79 10.5 13.9
untitled Green
Flaming Gorge Reservoir 2769.2 89 74 3148.8 101 3103.0 3749.0
untitled Strawberry
Strawberry Reservoir, Soldier Springs 875.8 101 79 903.7 105 864.6 1105.9
Starvation Reservoir, Duchesne, Nr 152.2 99 92 153.0 99 153.9 165.3
untitled Rock Ck
Upper Stillwater Reservoir 18.4 123 59 21.4 143 15.0 31.4
untitled Lake Fork
Moon Lake Reservoir, Mtn Home, Nr 30.2 121 83 13.8 55 24.9 36.5
untitled Big Brush Ck
Red Fleet Reservoir, Vernal, Nr 15.6 68 61 17.1 75 22.8 25.7
untitled Price
Scofield Reservoir, Scofield, Nr 31.7 73 48 33.3 77 43.1 65.8
untitled Seeley Ck
Joes Vly Reservoir, Orangeville, Nr 37.4 76 60 37.6 77 49.0 62.5
untitled Huntington Ck
Electric Lake 15.6 69 49 18.0 80 22.6 31.5
untitled
TOTAL 4163.5 91 73 4541.8 100 4555.2 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 424.5 111 87 401.4 105 382.8 490.3
untitled Willow Ck
Willow Ck Reservoir, Granby, Nr 7.1 81 78 7.4 84 8.8 9.1
untitled Williams Fork
Williams Fork Reservoir, Parshall 88.2 110 91 73.0 91 79.8 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 49.0 83 74 64.6 110 59.0 66.0
untitled Blue
Dillon Reservoir 215.6 94 85 222.9 97 228.9 254.0
Green Mtn Reservoir 79.3 83 54 70.8 74 95.3 146.9
untitled Homestake Ck
Homestake Reservoir 15.3 65 35 19.7 84 23.5 43.0
untitled Frying Pan
Ruedi Reservoir, Basalt, Nr 74.7 96 73 68.4 88 77.5 102.0
untitled Plateau Ck
Vega Reservoir, Collbran, Nr 26.2 85 80 17.4 57 30.8 32.9
untitled Taylor
Taylor Park Reservoir 74.0 95 70 70.1 90 78.2 106.2
untitled Gunnison
Blue Mesa Reservoir 334.9 58 40 350.0 60 580.7 827.9
Morrow Point Reservoir 110.9 99 95 113.1 101 111.6 117.0
Crystal Reservoir 16.5 98 94 17.1 102 16.8 17.5
untitled Muddy Ck
Paonia Reservoir, Bardine, Nr 15.6 113 94 15.7 113 13.8 16.7
untitled Uncompahgre
Ridgway Reservoir 65.8 96 79 61.4 89 68.6 83.0
untitled Dolores
Mcphee Reservoir 257.3 77 68 189.0 57 333.2 381.1
untitled
TOTAL 1855.0 85 66 1761.7 80 2189.2 2790.6
Colorado
Lake Powell 6346.0 42 26 8366.4 55 15119.4 24322.0
untitled
TOTAL 6346.0 42 26 8366.4 55 15119.4 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 73.0 92 58 56.6 72 79.1 125.4
untitled San Juan
Navajo Reservoir, Archuleta, Nr 898.3 67 53 1044.6 77 1350.6 1696.0
untitled Florida
Lemon Reservoir, Durango, Nr 19.0 84 48 13.2 59 22.6 39.8
untitled
TOTAL 990.3 68 53 1114.4 77 1452.2 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