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Colorado State Basin Outlook Report for April, 2012


	COLORADO Water Supply Outlook Report as of April 1, 2012

March was a very dry month across Colorado, marking the fourth 
consecutive month of below average snowpack and year to date 
precipitation totals for the state.  Statewide snowpack percentages 
declined dramatically after a brief boost on March 1, leaving the 
state with the lowest snowpack percentage reported since 2002 and the 
second lowest in the entire 45 year historical record.  Forecasts for 
spring and summer streamflow volumes are well below average across 
the entire state. While many water users may have a feeling of déjà 
vu remembering conditions in 2002, reservoir storage provides a 
little optimism going into this runoff season.  Most of the state's 
major river basins are reporting above average reservoir storage with 
the notable exceptions of the Upper Rio Grande and Arkansas basins. 
Judicious use of existing supplies will be critical in minimizing 
impacts and there is always the potential for unexpected late season 
snowfall and above average spring precipitation to help ease impacts.


	SNOWPACK

Colorado's statewide snowpack percentage took a huge hit during 
March.  The current readings are now only 52 percent of average down 
29 percentage points from the report on March 1.  The current 
snowpack is just 46 percent of last year's April 1 snowpack report.  
Not since the memorable drought year of 2002, when the state also had 
an April 1 snowpack that was 52 percent of average, has conditions 
been this poor.  Exacerbating matters is the fact that by this date, 
nearly 100 percent of the seasonal snowpack has accumulated in an 
average year. Currently, the lowest snowpack percentages occur in the 
Colorado and combined Yampa and White River basins which are 49 and 
47 percent of average respectively.  The combined San Juan, Animas, 
Dolores, and San Miguel basins are reporting only 54 percent of 
average.  This past month, the Upper Rio Grande basin saw its 
snowpack percentage decrease sharply from last month’s reading of 83 
percent of average and is currently only 53 percent. The state's best 
snowpack percentage occurs in the North Platte basin which is 
reporting a snowpack at 57 percent of average, the Arkansas and 
Gunnison basins follow close behind, both reporting 56 percent of 
average. All basins have percentages well below those reported last 
year at this time; ranging from only 38 percent of last year in the 
Colorado basin, to a high of 69 percent of last year in the Upper Rio 
Grande basin.  During March, warm temperatures induced snowmelt at a 
number of SNOTEL sites.  Across southern Colorado, some lower 
elevation sites have already melted out and earlier season melt is 
even occurring at the higher elevation sites.  At current melt rates; 
many sites will be completely melted out about a month earlier than 
normal.


	PRECIPITATION

Precipitation totals for March, measured at NRCS SNOTEL sites, were 
well below average across the state. Statewide precipitation for the 
month was a dismal 29 percent of average. The South Platte was the 
driest basin with precipitation totals at only 17 percent of average. 
The Arkansas and Upper Rio Grande basins recorded the highest monthly 
totals in the state at 41 and 40 percent of average respectively. The 
remaining basins ranged from 27 percent of average in the Colorado 
basin to 36 percent of average in the Gunnison basin.  Water year 
precipitation totals have dropped to below average in all basins but 
year to date percentages are still slightly skewed by the abnormally 
wet conditions in October.  Basin wide water year totals range from 
only 70 percent of average in the Colorado basin, to a high of 91 
percent of average in the Upper Rio Grande basin. Water year to date 
precipitation for the state is 78 percent of average.  


	RESERVOIR

Statewide reservoir storage was reported to be 108 percent of average 
at the end of March.  The combined Yampa and White River basins boast 
the highest storage amounts in the state, currently storing 128 
percent of average volumes for this date.  Storage volumes in the 
other major basins range from only 73 percent of average in the Upper 
Rio Grande basin, to 122 percent of average in the Gunnison River 
basin.  Statewide 2012 storage volumes are slightly above where they 
were this time last year.  Only the Arkansas and Upper Rio Grande 
basins are reporting volumes less than those reported last year.  The 
Arkansas basin average storage is currently at only 86 percent of 
average and 95 percent of last year’s amounts. Storage in the Upper 
Rio Grande basin continues to be the lowest in the state, at only 73 
percent of average. Reservoirs in the state are currently at 60 
percent of capacity.


	STREAMFLOW

Colorado's water users can anticipate very low streamflow volumes 
this summer. Due to extremely poor snowpack conditions spring and 
summer streamflow volumes may approach the minimum volumes on record. 
Projected inflow into Dillon Reservoir is only 60 percent of average 
and forecasts elsewhere in the Colorado basin are slightly lower. 
Clear Creek at Golden is expected to flow at 66 percent of average 
this season. The forecast for the Cache la Poudre River is only 53 
percent of average.  The Gunnison River near Gunnison is only 
expected to see volumes at 45 percent of average. All of these 
forecasts assume normal precipitation amounts throughout the April to 
July forecast period.  Should the current weather trend continue into 
spring and summer, these forecasts will continue to decline even 
further.
	

Special Note on Interpreting Forecasts

According to the National Water and Climate Center (NWCC), “a water 
supply forecast is a prediction of streamflow volume that will flow 
past a point on a stream during a specified season, typically in the 
spring and summer.  These forecasts are given not as a single number, 
but as a range of numbers to reflect risk and forecast uncertainty. 
Each month, five forecasts are issued for each forecast point and 
each forecast period. Unless otherwise specified, all forecasts are 
for streamflow volumes that would occur naturally without any 
upstream influences.”
The forecasts we typically emphasize in this report are the 50 
percent exceedance probability forecasts because they are in the 
middle of the range of forecasts with 50 percent chance that actual 
volumes will be above or below the predicted volume. The 50 percent 
exceedance forecasts assume that typical weather patterns will 
prevail into the forecast season. In a water year such as this one, 
when conditions have been anything but typical, it is important to 
pay attention to the other forecasts provided. If the dry conditions 
that occurred in March continue into the rest of spring and summer it 
may be prudent to use the 70 or 90 percent exceedance forecasts for 
management purposes this season. If we receive late season snowfall 
or above average precipitation this spring, actual streamflow volumes 
may be more in line with the 50 or 30 percent exceedance forecasts.


	GUNNISON RIVER BASIN as of April 1, 2012

In the last few weeks of March the snowpack in the Gunnison River 
basin began melting. April 1 measurements show the basin's snowpack 
at just 56 percent of average. If April proves to be as warm and dry 
as March was, what little snow is left will rapidly disappear. Sub-
basin snowpack's all decreased significantly from what was reported 
on March 1. The Uncompahgre watershed saw the largest drop from 88 
percent of average on March 1 to 56 percent on April 1.The other sub-
basins snowpack's current reports ranged from 70 percent of average 
in the Surface Creek drainage to 57 percent of average reported for 
the Upper Gunnison.
In March the basin received even less precipitation than the meager 
totals recorded in December of this water year. Precipitation 
measured at SNOTEL sites in the Gunnison basin was a just 36 percent 
of average for the month. Year to date precipitation totals dropped 
from 88 percent of average on March 1 to 78 percent of average as of 
April 1. Reservoir storage in the basin continues to track along at 
above average with reservoirs storing 808,000 acre-feet, 145,000 
acre-feet more than is typically stored this time of year. Current 
water supply forecasts have dropped an average of 20 percent from 
those issued last month. At this point well below average runoff 
volumes are expected at all forecast points in the basin, ranging 
from 36 percent of average expected for Tomichi Creek at Gunnison to 
67 percent of average for Ridgway Reservoir Inflow.

================================================================================
                              GUNNISON RIVER BASIN
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
Taylor Park Reservoir Inflow (2)
   APR-JUL       36       45        52       51        59       71       103  

Slate R nr Crested Butte
   APR-JUL       38       43        47       53        51       56        89  

East R at Almont
   APR-JUL       63       77        88       46        99      118       192  

Gunnison R near Gunnison (2)
   APR-JUL      116      150       175       45       200      245       390  

Tomichi Ck at Sargents
   APR-JUL      9.1     12.4      15.0       47      18.0       23        32  

Cochetopa Ck bl Rock Ck nr Parlin
   APR-JUL      3.6      5.6       7.3       42       9.4     13.0      17.3  

Tomichi Ck at Gunnison
   APR-JUL     13.6       22        29       36        38       53        81  

Lake Fk at Gateview
   APR-JUL       57       69        78       62        88      103       126  

Blue Mesa Reservoir Inflow (2)
   APR-JUL      225      285       330       46       375      455       720  

Paonia Reservoir Inflow (2)
   MAR-JUN       37       48        56       56        65       80       100  
   APR-JUN       29       40        48       51        57       72        95  
   APR-JUL       26       37        46       45        56       72       102  

NF Gunnison R nr Somerset (2)
   APR-JUL      113      137       155       51       174      205       305  

Surface Ck at Cedaredge
   APR-JUL      6.8      8.6      10.0       59      11.5     14.0      17.1  

Ridgway Reservoir Inflow (2)
   APR-JUL       46       59        68       67        78       94       102  

Uncompahgre R at Colona (2)
   APR-JUL       48       67        82       59        98      125       139  

Gunnison R nr Grand Junction (2)
   APR-JUL      455      605       720       46       845     1050      1560  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              GUNNISON RIVER BASIN
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
BLUE MESA                        830.0        538.9        494.9        404.5   
CRAWFORD                          14.0          9.0          7.9         10.8   
FRUITGROWERS                       3.6          3.6          3.6          4.0   
FRUITLAND                          9.2          3.0          2.3          2.5   
MORROW POINT                     121.0        114.0        112.5        113.6   
PAONIA                            15.4          1.0          0.7          4.6   
RIDGWAY                           83.0         70.9         64.0         60.9   
TAYLOR PARK                      106.0         67.2         73.0         61.9   
================================================================================

================================================================================
                              GUNNISON RIVER BASIN
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
UPPER GUNNISON BASIN                 15                 48                 57
SURFACE CREEK BASIN                   3                 57                 70
UNCOMPAHGRE BASIN                     4                 54                 56
TOTAL GUNNISON RIVER BASIN           19                 49                 56
================================================================================


	UPPER COLORADO RIVER BASIN as of April 1, 2012

It seems that snow accumulation in the Colorado River basin may have 
already reached its peak in early March. The paltry snowpack the 
basin had accumulated this winter has diminished by 26 percent since 
the beginning of March. As of April 1, snow surveys reported the 
snowpack in the basin to be at 49 percent of average, this is the 
lowest April 1 snowpack percentage on record in the basin. Snowpack 
percentages in the sub-basins are quite variable, ranging from a 
high, 70 percent of average, report for the Plateau Creek drainage to 
just 47 percent of average recorded in the Roaring Fork and Upper 
Colorado basins.
March precipitation in the basin was just 27 percent of average 
making this the fifth month in a row that precipitation has been 
below normal. The lack of moisture in March reduced total water year 
precipitation in the basin from 80 percent of average on March 1 to 
70 percent of average measured on April 1. Fortunately the combined 
reservoir storage levels in the basin are 20 percent above average 
and 6 percent greater than they were this time last year.  Current 
water supply forecasts have decreased significantly from those issued 
last month. The largest decrease was for Muddy Creek below Wolford 
Mountain Reservoir, which is down 33 percentage points to just 42 
percent of average as of April 1. Elsewhere in the basin spring and 
summer runoff is expected to be range from 47 to 67 percent of 
average

================================================================================
                              UPPER COLORADO RIVER BASIN
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
Lake Granby Inflow (2)
   APR-JUL      102      130       150       67       172      205       225  

Willow Ck Reservoir Inflow (2)
   APR-JUL     11.9     18.6        24       47        30       40        51  

Williams Fk Reservoir Inflow (2)
   APR-JUL       38       48        55       58        63       75        95  

Dillon Reservoir Inflow (2)
   APR-JUL       68       86       100       60       115      138       167  

Green Mountain Reservoir Inflow (2)
   APR-JUL      116      147       170       61       195      235       280  

Muddy Ck bl Wolford Mtn Resv (2)
   APR-JUL     12.4     19.4        25       42        31       42        60  

Eagle R bl Gypsum (2)
   APR-JUL      118      153       180       54       210      255       335  

Colorado R nr Dotsero (2)
   APR-JUL      485      645       770       54       905     1120      1440  

Ruedi Reservoir Inflow (2)
   APR-JUL       53       66        75       53        85      100       141  

Roaring Fk at Glenwood Springs (2)
   APR-JUL      275      335       380       54       425      500       710  

Colorado R nr Cameo (2)
   APR-JUL      855     1100      1280       53      1470     1790      2420  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              UPPER COLORADO RIVER BASIN
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
DILLON                           254.0        243.1        221.8        214.5   
LAKE GRANBY                      465.6        338.2        320.6        263.7   
GREEN MOUNTAIN                   146.8         72.9         59.4         59.8   
HOMESTAKE                         43.0          0.5         23.4         22.5   
RUEDI                            102.0         71.3         64.7         61.9   
VEGA                              32.9         18.8         14.2         13.1   
WILLIAMS FORK                     97.0         82.4         79.5         54.8   
WILLOW CREEK                       9.1          6.6          5.7          6.8   
================================================================================

================================================================================
                              UPPER COLORADO RIVER BASIN
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
BLUE RIVER BASIN                      9                 39                 53
UPPER COLORADO RIVER BASIN           36                 37                 47
MUDDY CREEK BASIN                     4                 45                 63
PLATEAU CREEK BASIN                   3                 57                 70
ROARING FORK BASIN                    8                 39                 47
WILLIAMS FORK BASIN                   4                 40                 51
WILLOW CREEK BASIN                    4                 36                 60
TOTAL COLORADO RIVER BASIN           47                 39                 49
================================================================================


	SOUTH PLATTE RIVER BASIN as of April 1, 2012

The South Platte River basin's snowpack, while still above the 
statewide average, saw the largest decrease from conditions reported 
at the beginning of March.  The basin's snowpack dropped 34 
percentage points from 89 percent of average on March 1 to 55 percent 
of average on April 1. Unless the basin benefits from late season 
storms this spring, snow accumulation in the South Platte River basin 
has likely already peaked. The sub-basin's snow survey results range 
from only 49 percent of average in the Upper South Platte watershed, 
to 60 percent of average in the Saint Vrain watershed.  If warm 
temperatures and lack of snowfall continue this spring, the snowpack 
could disappear as many as 45 days earlier than the typical melt out 
date in some locations.  
Precipitation received in the basin during March was a bleak 17 
percent of average, the lowest percentage in the state. Precipitation 
for the water year is now only 79 percent of average.  Combined 
reservoir storage was a healthy 104 percent of average at the end of 
March. All streamflow forecasts for the basin have decreased from 
last month's predictions. They now range from only 45 percent of 
average for the Inflow to Elevenmile Canyon Reservoir to73 percent of 
average for Boulder Creek near Orodell. It is suggested that if dry 
and warm conditions persist in the basin this spring that it may be 
prudent for water users to use the 70 or 90 percent exceedance 
forecasts for management purposes.

================================================================================
                              SOUTH PLATTE RIVER BASIN
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
Antero Reservoir Inflow (2)
   APR-JUL      5.9      8.6      11.1       66      14.4       21      16.8  
   APR-SEP      6.8     10.1      13.3       61      17.5       26        22  

Spinney Mountain Res Inflow (2)
   APR-JUL     14.1       20        26       46        33       48        56  
   APR-SEP     16.5       24        32       46        42       62        69  

Elevenmile Canyon Res Inflow (2)
   APR-JUL     13.7       20        26       45        34       49        58  
   APR-SEP     15.7       24        32       44        43       65        72  

Cheesman Lake Inflow (2)
   APR-JUL       26       40        52       46        68      102       114  
   APR-SEP       32       49        65       46        86      131       140  

South Platte R at South Platte (2)
   APR-JUL       44       69        94       46       128      205       205  
   APR-SEP       54       86       118       46       162      260       255  

Bear Ck ab Evergreen
   APR-JUL      5.4      8.5      11.6       60      15.8       25      19.3  
   APR-SEP      7.5     11.8      16.0       64        22       34        25  

Bear Ck at Morrison
   APR-JUL      5.4      9.4      13.7       55      19.9       34        25  
   APR-SEP      7.5     12.9      18.6       60        27       46        31  

Clear Ck at Golden
   APR-JUL       41       59        72       66        85      103       110  
   APR-SEP       48       73        90       67       107      132       134  

St. Vrain Ck at Lyons (2)
   APR-JUL       49       59        66       70        73       83        94  
   APR-SEP       57       69        77       71        85       97       109  

Boulder Ck nr Orodell (2)
   APR-JUL       27       33        38       73        43       49        52  
   APR-SEP       30       39        45       75        51       60        60  

S Boulder Ck nr Eldorado Springs (2)
   APR-JUL       20       26        29       71        32       38        41  
   APR-SEP       23       29        34       74        39       45        46  

Big Thompson R at Canyon Mouth (2)
   APR-JUL       43       56        65       66        74       87        99  
   APR-SEP       52       68        79       66        90      106       119  

Cache La Poudre at Canyon Mouth (2)
   APR-JUL       87      110       130       53       153      195       245  
   APR-SEP       98      125       147       54       173      220       275  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              SOUTH PLATTE RIVER BASIN
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
ANTERO                            19.9         16.0         20.0         15.9   
BARR LAKE                         30.1         28.6         29.3         27.9   
BLACK HOLLOW                       6.5          3.6          2.7          4.0   
BOYD LAKE                         48.4         40.2         36.5         33.0   
BUTTON ROCK/RALPH PRICE           16.2         12.5         12.8         12.1   
CACHE LA POUDRE                   10.1         10.6         10.4          8.6   
CARTER                           108.9         74.6         88.2        100.9   
CHAMBERS LAKE                      8.8          5.8          3.6          3.3   
CHEESMAN                          79.0         66.8         71.2         60.8   
COBB LAKE                         22.3         19.2         20.0         13.9   
ELEVEN MILE                       98.0         99.8         99.4         96.4   
EMPIRE                            36.5         36.4         36.5         31.8   
FOSSIL CREEK                      11.1          9.5          7.4          7.9   
GROSS                             41.8         28.1         19.5         23.9   
HALLIGAN                           6.4          5.0          5.0          4.7   
HORSECREEK                        14.7         12.2         13.0         13.9   
HORSETOOTH                       149.7        137.5        104.7        119.1   
JACKSON                           26.1         26.1         25.5         29.9   
JULESBURG                         20.5         20.5         20.5         20.8   
LAKE LOVELAND                     10.3          9.1          7.5          9.0   
LONE TREE                          8.7          7.8          7.4          7.2   
MARIANO                            5.4          3.1          4.4          4.5   
MARSHALL                          10.0          8.5          4.6          6.0   
MARSTON                           13.0          4.7          3.1         13.3   
MILTON                            23.5         21.7         22.5         18.3   
POINT OF ROCKS                    70.6         69.4         70.6         68.8   
PREWITT                           28.2         24.5         24.4         25.0   
RIVERSIDE                         55.8         55.6         55.7         58.2   
SPINNEY MOUNTAIN                  49.0         46.4         39.1         32.1   
STANDLEY                          42.0         36.5         32.1         34.6   
TERRY LAKE                         8.0          5.5          5.2          5.4   
UNION                             13.0         12.3         12.2         11.1   
WINDSOR                           15.2         12.6         11.0         12.4   
================================================================================

================================================================================
                              SOUTH PLATTE RIVER BASIN
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
BIG THOMPSON BASIN                    7                 42                 57
BOULDER CREEK BASIN                   5                 49                 58
CACHE LA POUDRE BASIN                 8                 39                 55
CLEAR CREEK BASIN                     4                 42                 58
SAINT VRAIN BASIN                     4                 52                 60
UPPER SOUTH PLATTE BASIN             16                 51                 49
TOTAL SOUTH PLATTE BASIN             44                 44                 55
================================================================================


	YAMPA, WHITE, AND NORTH PLATTE RIVER BASINS as of April 1, 2012

The combined Yampa, White, North Platte and Laramie River basins did 
not receive noteworthy snowfall in March.  According to preliminary 
SNOTEL data, March snowfall in these basins was a mere 19 percent of 
average, all of which occurred during the first week of the month. 
April 1 snow surveys showed the snowpack at 52 percent of average and 
just 39 percent of what was reported this time last year. The Yampa 
and White basins snowpack reports were lower than the combined basin 
at just 49 and 46 percent of average respectively. The North Platte 
and Little Snake basins reports were higher than the combined basins 
at 57 and 56 percent of average respectively. 
Precipitation in these basins during March was just 28 percent of 
average, knocking the year to date precipitation down to 73 percent 
of average as of April 1. This is the fourth consecutive month to 
report below average year to date precipitation.  Reservoir storage 
in Stagecoach and Yamcolo reservoirs has increased for the third 
month in a row with current storage levels at 128 percent of average.  
After a boost last month, water supply forecasts plunged back down to 
well below average across the basins. The North Platte near Northgate 
currently has the lowest forecast as a percent of average in the 
state; it is expected to run at 20 percent of average from April to 
July. Elsewhere in the basins seasonal forecasts range from 68 
percent of average for the Laramie near Woods Landing to 39 percent 
of average on Elkhead Creek near Hayden.

================================================================================
                              YAMPA, WHITE, AND NORTH PLATTE RIVER BASINS
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
North Platte R nr Northgate
   APR-JUL       20       32        50       20        88      143       245  
   APR-SEP       23       38        57       21       100      163       270  

Laramie R nr Woods
   APR-JUL       44       67        83       68        99      122       123  
   APR-SEP       48       74        92       68       110      136       135  

Yampa R ab Stagecoach Reservoir (2)
   APR-JUL      5.9      9.2      12.0       52      15.4       21        23  

Yampa R at Steamboat Springs (2)
   APR-JUL      101      129       150       54       172      210       280  

Elk R nr Milner
   APR-JUL      133      166       190       59       215      255       325  

Elkhead Ck ab Long Gulch nr Hayden
   APR-JUL     13.7       22        28       39        35       47        71  

Yampa R nr Maybell (2)
   APR-JUL      320      410       500       51       600      780       990  

Little Snake R nr Slater (2)
   APR-JUL       52       68        80       50        93      114       159  

Little Snake R nr Savery (2)
   APR-JUL       97      143       180       55       220      290       330  

Little Snake R nr Lily (2)
   APR-JUL       88      141       185       51       235      310       365  

White R nr Meeker
   APR-JUL      106      137       160       55       185      225       290  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              YAMPA, WHITE, AND NORTH PLATTE RIVER BASINS
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
STAGECOACH                        36.4         33.7         21.3         24.6   
YAMCOLO                            8.7          6.6          8.1          6.9   
================================================================================

================================================================================
                              YAMPA, WHITE, AND NORTH PLATTE RIVER BASINS
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
LARAMIE RIVER BASIN                   4                 48                 65
NORTH PLATTE RIVER BASIN             11                 39                 54
TOTAL NORTH PLATTE BASIN             14                 42                 57
ELK RIVER BASIN                       2                 35                 47
YAMPA RIVER BASIN                    12                 35                 49
WHITE RIVER BASIN                     6                 39                 46
TOTAL YAMPA AND WHITE RIVER          17                 36                 47
LITTLE SNAKE RIVER BASIN              8                 43                 56
TOTAL YAMPA, WHITE AND NORTH         36                 39                 52
================================================================================


	ARKANSAS RIVER BASIN as of April 1, 2012

The snowmelt and runoff season is underway in the Arkansas basin. 
While the basin did receive some additional snow accumulation in the 
last month, the early melt out dramatically altered the snowpack 
average compared to last month. At the beginning of March, the 
snowpack was at 86 percent of average yet on April 1 the overall 
snowpack percentage for the basin had fallen to 56 percent of 
average. The Upper Arkansas sub-basin reported 52 percent of average 
snowpack conditions while the combined Cucharas and Huerfano 
drainages and the Purgatoire sub-basin recorded 70 and 66 percent of 
average conditions respectively.  . 
Year to date precipitation for the basin was 79 percent as of April 
1. Monthly totals for March registered a meager 41 percent of the 
average; this is the fifth month in a row to report below average 
precipitation in the basin. Reservoir storage within the Arkansas 
basin has dropped from 98 percent of average at the end of February 
to 86 percent of average at the end of March. Current streamflow 
forecasts for the basin have decreased anywhere between 20 and 40 
percent from those issued last month. The Arkansas River at Salida is 
forecast to flow at 50 percent of average, Chalk Creek near Nathrop 
is expected to flow at 40 percent of average and the Purgatoire River 
at Trinidad is expected to flow at 61 percent of average from April 
to July.

================================================================================
                              ARKANSAS RIVER BASIN
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
Chalk Ck nr Nathrop
   APR-JUL      3.9      6.8       9.2       40      12.0     16.7        23  
   APR-SEP      5.4      9.0      12.0       44      15.4       21        27  

Arkansas R at Salida (2)
   APR-JUL      113      122       128       50       134      144       255  
   APR-SEP      130      144       155       50       166      183       310  

Grape Ck nr Westcliffe
   APR-JUL      3.6      4.9       5.9       37       7.0      8.7      16.1  
   APR-SEP      6.0      7.2       8.0       41       8.9     10.3      19.6  

Arkansas R ab Pueblo (2)
   APR-JUL       95      144       185       48       230      315       385  
   APR-SEP       68      193       245       51       305      415       485  

Huerfano R nr Redwing
   APR-JUL      3.7      5.7       7.4       60       9.2     12.3      12.3  
   APR-SEP      5.2      7.8       9.8       63      12.1     15.8      15.5  

Cucharas R nr La Veta
   APR-JUL      2.7      5.0       6.9       61       9.1     13.0      11.3  
   APR-SEP      3.7      6.1       8.1       62      10.4     14.2      13.0  

Purgatoire R at Trinidad (2)
   MAR-JUL      6.4     13.8        21       62        29       44        34  
   APR-JUL      5.2     12.6      19.5       61        28       43        32  
   APR-SEP     17.7       23        27       61        31       38        44  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              ARKANSAS RIVER BASIN
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
ADOBE                             62.0         40.5         40.6         37.0   
CLEAR CREEK                       11.4          7.8          8.5          6.7   
CUCHARAS RESERVOIR                40.0          0.1          0.1          5.4   
GREAT PLAINS                     150.0          0.0          0.0         41.9   
HOLBROOK                           7.0          2.0          0.9          4.9   
HORSE CREEK                       27.0          0.0          0.0         12.6   
JOHN MARTIN                      616.0         45.5         64.1        137.3   
LAKE HENRY                         8.0          7.8          9.0          6.7   
MEREDITH                          42.0         37.0         39.7         19.0   
PUEBLO                           354.0        244.1        264.1        173.3   
TRINIDAD                         167.0         17.0         20.1         27.5   
TURQUOISE                        127.0         63.8         44.8         74.0   
TWIN LAKES                        86.0         39.1         39.0         42.5   
================================================================================

================================================================================
                              ARKANSAS RIVER BASIN
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
UPPER ARKANSAS BASIN                 10                 45                 52
CUCHARAS & HUERFANO RIVER BA          4                114                 70
PURGATOIRE RIVER BASIN                2                120                 65
TOTAL ARKANSAS RIVER BASIN           15                 54                 56
================================================================================


	UPPER RIO GRANDE BASIN as of April 1, 2012

Although there was some additional snowfall in the Upper Rio Grande 
River basin during March, early snowmelt has reduced the snowpack 
percentage by 30 percentage points from the report issued March 1. 
Current measurements are only 53 percent of average as of April 1, 
which is just 69 percent of the snowpack measured last year at this 
time. Snowpack measurements range from only 21 percent of average in 
the Alamosa Creek watershed, to 59 percent of average in the Upper 
Rio Grande sub-basin. 
Precipitation during March was only 40 percent of the average monthly 
total. Total year to date precipitation was 91 percent of average as 
of April 1, this is the first month in this water year that 
cumulative precipitation has fallen below average in the basin.  
Reservoirs in the basin are storing volumes that are 73 percent of 
average as of April 1. This is approximately 8,000 acre-feet less 
than was available last year at this time.  Current streamflow volume 
forecasts for April to September are below 74 percent of average at 
all forecast points in the basin. They range from only 35 percent of 
average for the San Antonio River at Ortiz to 74 percent of average 
at the Rio Grande at Thirty Mile Bridge. It is suggested that if dry 
and warm conditions persist in the basin this spring that it may be 
prudent for water users to use the 70 or 90 percent exceedance 
forecasts for management purposes.

================================================================================
                              UPPER RIO GRANDE BASIN
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
Rio Grande at Thirty Mile Bridge (2)
   APR-SEP       72       88       101       74       114      135       136  
   APR-JUL       64       76        85       72        95      110       118  

Rio Grande at Wagon Wheel Gap (2)
   APR-SEP      169      215       250       73       285      345       345  

SF Rio Grande at South Fork (2)
   APR-SEP       68       81        91       69       101      118       132  

Rio Grande nr Del Norte (2)
   APR-SEP      265      330       375       71       425      510       531  

Saguache Ck nr Saguache (2)
   APR-SEP     10.8     15.9        20       61        25       32        33  

Alamosa Ck ab Terrace Reservoir
   APR-SEP       35       42        48       69        54       64        70  

La Jara Ck nr Capulin
   MAR-JUL      3.6      4.8       5.8       67       7.0      9.1       8.7  
   APR-JUL      2.3      3.5       4.5       56       5.7      7.8       8.0  

Trinchera Ck ab Turners Ranch
   APR-SEP      3.3      5.3       7.0       58       8.9     12.1      12.0  

Sangre de Cristo Ck (2)
   APR-SEP      0.3      2.1       4.1       47       6.8     12.1       8.8  

Ute Creek
   APR-SEP      1.8      4.5       7.0       57      10.0     15.5      12.2  

Platoro Reservoir Inflow
   APR-JUL       33       39        43       67        48       56        64  
   APR-SEP       36       43        48       68        53       62        71  

Conejos R nr Mogote (2)
   APR-SEP      105      125       140       70       156      182       200  

San Antonio R at Ortiz
   APR-SEP      3.0      4.5       5.8       35       7.3     10.1      16.4  

Los Pinos R nr Ortiz
   APR-SEP       25       32        38       51        44       55        74  

Culebra Ck at San Luis (2)
   APR-SEP      5.3      8.8      12.0       52      15.8       23        23  

Costilla Reservoir Inflow
   MAR-JUL      3.1      4.3       5.4       51       6.7      8.9      10.6  
   APR-JUL      2.4      3.6       4.7       47       6.0      8.2      10.1  

Costilla Ck nr Costilla (2)
   MAR-JUL      6.2      9.1      11.7       45      14.9       21        26  
   APR-JUL      4.3      7.2       9.8       41      13.0     18.7        24  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              UPPER RIO GRANDE BASIN
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
CONTINENTAL                       27.0          5.8          5.6          5.9   
PLATORO                           60.0         15.5         21.6         24.5   
RIO GRANDE                        51.0         21.3         19.7         19.3   
SANCHEZ                          103.0          9.0         16.8         24.9   
SANTA MARIA                       45.0          8.5          6.9         10.8   
TERRACE                           18.0          7.6          5.2          7.6   
================================================================================

================================================================================
                              UPPER RIO GRANDE BASIN
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
ALAMOSA CREEK BASIN                   2                 45                 21
CONEJOS & RIO SAN ANTONIO BA          4                 63                 50
CULEBRA & TRINCHERA CREEK BA          5                 75                 48
UPPER RIO GRANDE BASIN               12                 71                 59
TOTAL UPPER RIO GRANDE BASIN         23                 69                 53
================================================================================


	SAN MIGUEL, DOLORES, ANIMAS, AND SAN JUAN RIVER BASINS as of April 1, 2012

Although the combined San Miguel, Dolores, Animas and San Juan River 
basins did receive additional snowfall in early March the amounts 
were nominal and the basins then lost 25 percent of their snowpack 
during the last week of March, according to preliminary SNOTEL data. 
April 1 snow measurements were just 54 percent of average for all the 
basins combined; a drop of 32 percentage points from surveys done on 
March 1. All sub-basins snowpack's were well below average as well, 
ranging from 59 percent of average in the San Juan basin to 45 
percent of average in the Dolores River basin.  
Prior to this month the San Miguel, Dolores, Animas and San Juan 
basins were one of only two major basins in the state with above 
average year to date precipitation. Minimal precipitation during 
March (32 percent of average) has caused year to date precipitation 
totals to drop to 88 percent of average as of April 1. Reservoirs in 
the basins have combined storage levels at 111 percent of average and 
106 percent of the levels reported last year at this time. As we head 
into the runoff season, forecasted spring and summer volumes for the 
rivers in these basins are now all expected to be less than 70 
percent of average.  Current forecasts range from 47 percent of 
average expected for the Inflow to McPhee Reservoir to 69 percent of 
average expected for the Inflow to Lemon Reservoir.

================================================================================
                              SAN MIGUEL, DOLORES, ANIMAS, AND SAN JUAN RIVER BASINS
                      Streamflow Forecasts - April 1, 2012
================================================================================
            |  <=== Drier ===  Future  Conditions  === Wetter ===>  |
            |                                                       |
Forecast Pt | ===============  Chance of Exceeding * ============== |
   Forecast |  90%       70%   |       50%       |  30%       10%   | 30 Yr Avg
   Period   |(1000AF)  (1000AF)|(1000AF) (% AVG.)|(1000AF)  (1000AF)| (1000AF)
================================================================================
Dolores R at Dolores
   APR-JUL       90      115       135       51       157      193       265  

McPhee Reservoir Inflow (2)
   APR-JUL       96      127       150       47       175      215       320  

San Miguel R nr Placerville
   APR-JUL       55       69        80       61        92      112       132  

Gurley Reservoir Inlet
   APR-JUL      7.9     10.1      11.7       64      13.5     16.5      18.3  

Cone Reservoir Inlet
   APR-JUL      0.6      1.3       2.0       61       2.9      4.6       3.3  

Lilylands Reservoir Inlet
   APR-JUL      1.0      1.4       1.7       58       2.1      2.7       2.9  

Rio Blanco at Blanco Diversion (2)
   APR-JUL       20       29        35       66        41       50        53  

Navajo R at Oso Diversion (2)
   APR-JUL       28       35        40       58        46       56        69  

San Juan R nr Carracas (2)
   APR-JUL      125      188       230       57       270      335       405  

Piedra R nr Arboles
   APR-JUL       97      123       140       61       157      183       230  

Vallecito Reservoir Inflow (2)
   APR-JUL       89      113       130       63       147      171       205  

Navajo Reservoir Inflow (2)
   APR-JUL      265      370       445       57       520      625       785  

Animas R at Durango
   APR-JUL      182      240       275       63       310      370       440  

Lemon Reservoir Inflow (2)
   APR-JUL       29       35        40       69        45       53        58  

La Plata R at Hesperus
   APR-JUL      9.4     12.0      14.0       56      16.2     19.8        25  

Mancos River Near Mancos
   APR-JUL     11.0     16.4        20       61        24       29        33  

================================================================================
   * 90%, 70%, 50%, 30%, and 10% chances of exceeding are the probabilities that
     the actual volume will exceed the volumes in the table.

   The average is computed for the 1971-2000 base period.

   (1) - The values listed under the 10% and 90% Chance of Exceeding are
         actually 5% and 95% exceedance levels.
   (2) - The value is natural volume - actual volume may be affected by upstream
         water management.
   (3) - Median value used in place of average.
================================================================================
                              SAN MIGUEL, DOLORES, ANIMAS, AND SAN JUAN RIVER BASINS
                   Reservoir Storage (1000AF) End of March
================================================================================
                                Usable     ********** Usable Storage *********
Reservoir                      Capacity    This Year    Last Year      Average
================================================================================
GROUNDHOG                         22.0          5.4         13.2         12.2   
JACKSON GULCH                     10.0          4.2          5.6          5.1   
LEMON                             40.0         16.2         15.1         21.2   
MCPHEE                           381.0        303.1        279.5        273.6   
NARRAGUINNEP                      19.0         19.0         18.9         15.5   
VALLECITO                        126.0         84.2         77.0         62.0   
================================================================================

================================================================================
                              SAN MIGUEL, DOLORES, ANIMAS, AND SAN JUAN RIVER BASINS
                   Watershed Snowpack Analysis - April 1, 2012
================================================================================
                                 Number of           This Year as Percent of
Watershed                        Data Sites          Last Year       Average
================================================================================
ANIMAS RIVER BASIN                    9                 66                 56
DOLORES RIVER BASIN                   6                 54                 45
SAN MIGUEL RIVER BASIN                5                 62                 51
SAN JUAN RIVER BASIN                  4                 64                 59
TOTAL SAN MIGUEL, DOLORES, A         23                 63                 54
================================================================================

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