Lake Powell Water Supply Outlook, January 1, 2017

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by CBRFC
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-July210 255 305 124 340 405
Pine Ck
Fremont Lk, Abv April-July87 97 110 112 121 138
New Fork
Big Piney, Nr April-July305 370 430 121 495 590
Green
Fontenelle Res, Fontenelle Nr April-July590 770 930 128 1080 1370
Big Sandy
Farson, Nr April-July41 54 62 119 70 89
Green
Green River, Wy, Nr April-July595 785 945 129 1120 1420
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July36 45 59 109 72 93
Viva Naughton Res April-July48 63 82 111 107 141
Blacks Fork
Robertson, Nr April-July60 83 94 106 112 134
Ef Smiths Fork
Stateline Res, Robertson,nr April-July19.2 23 27 104 32 39
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July780 1020 1230 126 1440 1990


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-July14.5 15.9 18.5 80 20 27
Steamboat Springs April-July131 167 225 87 260 315
Elk
Milner, Nr April-July200 250 325 102 370 410
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July36 55 75 103 86 95
Yampa
Maybell, Nr April-July475 645 875 94 1000 1200
Little Snake
Slater, Nr April-July71 100 145 93 170 194
Dixon, Nr April-July141 205 300 87 350 445
Lily, Nr April-July138 215 315 91 360 510
Yampa
Deerlodge Park April-July610 860 1180 95 1340 1600
White
Meeker, Nr April-July158 188 240 86 265 325
Watson, Nr April-July168 205 255 91 290 340


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-July14.6 20 22 105 27 32
Ashley Ck
Vernal, Nr April-July34 48 52 104 62 77
West Fork Duchesne
Vat Diversion, Blo April-July12.2 17.2 19.7 106 24 31
Duchesne
Tabiona, Nr April-July77 96 115 106 135 158
Rock Ck
Upper Stillwater Res April-July61 72 84 114 100 122
South Fork Rock Ck
Docs Div, Blo April-July5.5 7.1 8.2 112 10.1 12.6
Rock Ck
Mountain Home, Nr April-July72 86 99 113 120 150
Currant Ck
Currant Ck Res April-July13.4 17.8 21 105 25 33
Strawberry
Solider Springs,nr April-July35 56 69 97 88 119
Starvation Res, Duchesne, Nr April-July71 104 125 112 168 215
Duchesne
Duchesne, Nr, Knight Div, Abv April-July147 178 210 108 245 300
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July53 64 75 114 87 106
Yellowstone
Altonah, Nr April-July50 62 70 115 79 100
Whiterocks
Whiterocks, Nr April-July41 53 62 115 71 89
Uinta
Neola, Nr April-July54 70 85 115 100 123
Duchesne
Myton April-July210 295 365 111 455 585
Randlett, Nr April-July240 345 440 114 550 730


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-July7.8 16.3 20 129 25 28
Fish Ck
Scofield, Nr, Reservoir, Abv April-July23 28 34 113 42 48
Price
Scofield Res, Scofield, Nr April-July29 37 46 112 57 67
Green
Green River, Ut April-July2000 2560 3130 106 3520 4700
Huntington Ck
Electric Lake April-July9.2 12.2 15.6 117 19.2 23
Power Plant, Blo April-July32 43 49 123 63 71
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July39 49 61 109 69 85
Ferron Ck
Ferron, Nr April-July27 34 40 105 46 58
Muddy Ck
Emery, Nr April-July13.7 18.8 21 106 27 34


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-July135 170 215 98 245 330
Willow Ck
Willow Ck Res, Granby, Nr April-July25 38 50 106 58 85
Fraser
Winter Park April-July13 16 20 103 22 26
Williams Fork
Williams Fork Res, Parshall, Nr April-July60 78 95 99 107 135
Muddy Ck
Wolford Mountain Reservoir April-July24 38 52 96 66 85
Blue
Dillon Res April-July100 130 155 95 183 220
Green Mtn Res April-July165 215 260 95 300 380
Colorado
Kremmling, Nr April-July500 660 830 97 945 1240
Eagle
Gypsum, Blo April-July180 230 285 85 335 450
Colorado
Dotsero, Nr April-July790 1050 1300 93 1530 2030
Frying Pan
Ruedi Res, Basalt, Nr April-July73 97 120 86 140 190
Roaring Fork
Glenwood Springs April-July405 500 600 87 675 875
Colorado
Glenwood Springs, Blo April-July1220 1630 1920 91 2210 2900
Cameo, Nr April-July1380 1790 2120 90 2450 3300
Plateau Ck
Cameo, Nr April-July69 90 110 89 130 205
Colorado
Cisco, Nr April-July2500 3250 3900 88 4700 5800
Lake Powell, Glen Cyn Dam, At April-July4100 5330 6500 91 7750 9800


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 Res April-July62 76 81 82 102 137
Almont April-July95 117 125 81 160 220
East
Almont April-July105 135 158 87 188 270
Gunnison
Gunnison, Nr April-July220 285 310 84 400 575
Tomichi Ck
Gunnison April-July37 54 66 89 74 105
Lake Fork
Gateview April-July70 92 108 88 124 150
Gunnison
Blue Mesa Res April-July425 500 575 85 700 925
Morrow Point Res April-July475 550 625 84 750 975
Crystal Res April-July550 625 700 84 825 1050
Muddy Ck
Paonia Res, Bardine, Nr March-June55 68 83 86 90 120
April-July53 67 82 85 90 120
Nf Gunnison
Somerset, Nr April-July180 215 255 86 300 400
Surface Ck
Cedaredge April-July10 15 17 101 21 28
Uncompahgre
Ridgway Res April-July61 81 88 87 105 128
Colona April-July74 100 114 83 140 185
Delta April-July49 75 88 78 117 160
Gunnison
Grand Junction, Nr April-July950 1100 1250 84 1580 1930


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-July170 200 240 98 285 345
Mcphee Res April-July200 235 285 97 335 425
San Miguel
Placerville, Nr April-July75 95 110 86 130 165
Dolores
Cisco, Nr April-July320 390 500 88 580 815


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-July132 160 178 83 210 280
Carracas, Nr April-July225 275 310 82 375 520
Navajo Res, Archuleta, Nr April-July400 520 580 79 770 990
Farmington April-July625 815 900 82 1160 1450
Bluff, Nr April-July590 790 890 81 1130 1450
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July37 45 49 91 60 75
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July40 49 55 85 68 87
Piedra
Arboles, Nr April-July110 145 168 80 210 275
Los Pinos
Vallecito Res, Bayfield, Nr April-July122 150 172 89 205 250
Animas
Durango April-July270 345 390 94 435 505
Florida
Lemon Res, Durango, Nr April-July32 40 48 87 57 73
La Plata
Hesperus April-July14 19 24 104 29 36
Mancos
Mancos, Nr April-July22 30 34 110 42 55

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 Res, Fontenelle Nr 203.2 116 59 197.5 113 175.3 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 22.0 142 57 19.4 125 15.5 38.3
Blacks Fork
Meeks Cabin 9.7 94 33 5.6 54 10.3 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 6.0 104 43 5.7 99 5.8 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3130.4 101 83 3225.3 104 3094.9 3749.0
untitled Strawberry
Solider Springs,nr 766.8 116 69 792.0 120 659.7 1105.9
Starvation Res, Duchesne, Nr 142.1 106 86 144.7 108 134.1 165.3
untitled Rock Ck
Upper Stillwater Res 14.5 139 46 10.8 103 10.4 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr 22.3 100 61 19.9 89 22.4 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 20.8 119 81 15.6 89 17.5 25.7
untitled Price
Scofield Res, Scofield, Nr 12.3 43 19 9.8 34 28.5 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 29.8 75 48 37.1 94 39.7 62.5
untitled Huntington Ck
Electric Lake 15.9 81 51 17.3 88 19.6 31.5
untitled
TOTAL 4395.9 104 77 4500.7 106 4233.8 5700.4


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 453.9 121 93 468.3 125 375.1 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 7.8 102 86 7.9 104 7.6 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 75.8 114 78 79.3 119 66.5 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 51.1 113 77 43.5 97 45.1 66.0
untitled Blue
Dillon Res 228.4 101 90 236.6 104 226.9 254.0
Green Mtn Res 72.4 81 49 70.3 78 89.8 146.9
untitled Homestake Ck
Homestake Res -9999.0 -99 -99 41.4 126 32.9 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 69.6 91 68 71.9 94 76.8 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 11.1 93 34 11.2 94 12.0 32.9
untitled Taylor
Taylor Park Res 69.2 102 65 69.8 103 68.1 106.2
untitled Gunnison
Blue Mesa Res 592.5 108 71 624.5 114 549.9 829.5
Morrow Point Res 109.4 98 93 112.2 101 111.6 117.0
Crystal Res 16.5 108 94 15.3 99 15.4 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 1.6 38 10 1.1 25 4.2 16.7
untitled Uncompahgre
Ridgway Res 62.1 90 75 62.6 91 68.8 83.0
untitled Dolores
Mcphee Res 293.1 109 77 243.8 90 270.1 381.1
untitled
TOTAL 2114.6 106 77 2159.7 107 1987.9 2749.1
Colorado
Lake Powell 11796.9 66 49 11826.6 67 17744.8 24322.0
untitled
TOTAL 11796.9 66 49 11826.6 67 17744.8 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 Res, Bayfield, Nr 82.2 132 66 85.9 138 62.1 125.4
untitled San Juan
Navajo Res, Archuleta, Nr 1296.8 97 76 1397.0 104 1341.1 1696.0
untitled Florida
Lemon Res, Durango, Nr 20.2 98 51 20.8 101 20.7 39.8
untitled
TOTAL 1399.2 98 75 1503.8 106 1423.8 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 1981-2010 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