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

Upper Colorado 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 Cody Moser, Ashley Nielson
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Upper Colorado Summary




*Median of forecasts within each basin.


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.


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

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).

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

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


Hydrologist: Cody Moser, Ashley Nielson