| 2005 Weekly Update - Drought Conditions |
|
|
 |
| April 11, 2005 |
|
|
|
Umatilla Basin - McKay Reservoir (mouse over photo for more)
|
Umatilla Basin: The Umatilla River at Pendleton was flowing 588 cfs on April 11, 200, or about 55% of 1977 flows for the same date. There is currently sufficient water for all users, but flow is dropping as demand increases. Butter Creek is flowing at 18.5 cfs. The water master is regulating Butter Creek because there is insufficient water for all users.
In the Northeast portion of Oregon the water master reports precipitation has helped a great deal. However, flow in the Grande Ronde River above LaGrande has been consistently well below normal. A flow measurement on the river on April 8 totaled 438 cfs. This is about the peak flow so far this year, while the lowest flow recorded for the month of April in any of the past 5 years is 629 cfs. Prior to the recent rain, flow at the same location was less than half-current flow. Expected flow at this station for this time of year is typically 1000 to 2000 cfs. Flow in the river is expected to drop off quickly and remain low when the weather turns dry and warm.
Flow in the Willamette at Salem is above the target requested for fish by the fishery folks. If it keeps raining, we should be able to maintain that for a while. The Willamette Basin Project Reservoirs are up to about 700,000 acre-feet of conservation storage. About 400,000 acre-feet behind schedule, this is a big improvement over a month ago. Cottage Grove Reservoir and Dorena Reservoir are above normal operating level for this time of year, and Green Peter Reservoir is only about 4 feet below operating level. Detroit Reservoir is about 18 feet below normal operating level, but is gaining each day. Things are looking much better than they did 11 days ago.
Because of cooler weather and precipitation, stream flows are fairly strong although below average in the Hood River Basin. Hood River at Tucker Bridge on April 11 was 993 cfs, with the mean based on 44 years of record being 1353 cfs. A similar situation exists in the Fifteenmile Basin- flows are good but below average for this time of year. Precipitation for the month of March was 95% of average. However, since the beginning of the water year, only 56% of normal precipitation has fallen and snow pack is 25-30% of normal. April through September stream flow forecasts range from 42-50% of normal according to NRCS Water Supply Outlook Report, April 1, 2005).
The Governor issued a drought emergency declaration for Hood River County. Wasco County is collecting information and considering if/when to ask for a drought declaration. Rock Creek and Pine Hollow Reservoirs are approaching full capacity, but lack of natural flow may require the use of stored water earlier than usual.
Oregon Water Availability - Summary by Basin
Conditions listed as percent of normal for April 1, 2005
SWSI = Surface Water Supply Index
|
Basin
|
SWSI*
|
Snowpack
|
Reservoir
Content
|
Accumulated
Precipitation
|
Accumulated
Streamflow
|
Forecasted
Streamflow
|
|
Owyhee
|
-2.0
|
72%
|
46%
|
82%
|
34%
|
52%
|
|
Malheur
|
-2.3
|
72%
|
46%
|
82%
|
33%
|
29%
|
|
Grande Ronde,
Powder, Burnt
|
-2.8
|
53%
|
58%
|
70%
|
60%
|
41%
|
|
Umatilla
|
-3.0
|
26%
|
46%
|
54%
|
52%
|
46%
|
|
Upper John Day
|
-2.5
|
44%
|
-
|
67%
|
37%
|
48%
|
|
Upper Deschutes
|
-1.9
|
48%
|
92%
|
59%
|
43%
|
73%
|
|
Lower Deschutes
|
-3.3
|
48%
|
-
|
56%
|
48%
|
45%
|
|
Willamette
|
-3.0
|
31%
|
66%
|
57%
|
45%
|
59%
|
|
Rogue
|
-2.1
|
51%
|
95%
|
70%
|
44%
|
55%
|
|
Klamath
|
-2.2
|
51%
|
72%
|
68%
|
57%
|
42%
|
|
Lake
|
-1.4
|
73%
|
80%
|
68%
|
38%
|
55%
|
|
Harney
|
-1.9
|
46%
|
-
|
60%
|
53%
|
46%
|
|
North Coast
|
-2.6
|
-
|
-
|
70%
|
57%
|
-
|
|
South Coast
|
-2.4
|
-
|
-
|
70%
|
59%
|
-
|
|
| April 6, 2005 |
|
|
|
Deshutes River near Sunriver - (mouse over for more info.)
|
Water masters in central Oregon report the recent rain has improved conditions significantly. Although snow pack is still below normal, water conditions are better for agriculture. Initially, most irrigation districts were scheduled to start their canals on April 1st which, for them, is the start of irrigation season. However, most have delayed start-up by 4 days to nearly two weeks. This allows the districts to continue filling their reservoirs and thereby assure some water for later in the summer. The overall condition has improved, but severe water shortages are expected this summer due to low snow pack.
Flow in the Umatilla River at Pendleton is 950 cfs or 75% of average flow for the month of April. With the recent rain there is sufficient water available for all users on the Umatilla and Walla Walla Rivers. McKay Creek near Pilot Rock is flowing 107 cfs or 40% of average flow for the month of April. McKay Reservoir is storing 46% of normal and the water level is continuing to rise. Butter Creek near Pine City is flowing at 21 cfs. There is insufficient water for all users on Butter Creek, and the water master is currently denying water to some junior users.
In the southwest water conditions have improved and stream flows are running at near normal conditions. There has even been an increase in snow in the foothills, but the improvement is considered minor.
|
|
|
|
|
|
|
