BOARD02075

• Board Meeting Date: 5/22/2000
• Description: WSP Section - Colorado River Basin Issues - San Juan Basin Section 7 Consultation Issues
• Board Meetings - Doc Type: Memo

SOUTH PLATTE BASIN

Basinwide Conditions Assessment
The SWSI value of 1.5 indicates that for April the
. basin water supplies were above normal. Reservoir storage.
_the major component in this basin in computing the SWSI
lue, was normal as of the end of April. Storage in the
ajar plains reservoirs: Julesburg, North Sterling, and
Prewitt, increased overall by 320 acre-feet during April and
these reservoirs are at 93% of capacity. Storage in the
major upper basin reservoirs: Cheesman, Eleven Mile,
Spinney, and Antero, increased by 2,820 acre-feet overall
during April and these reservoirs are at 92% of capacity.
The Natural Resources Conservation Service reports that
May 1 snowpack is 85% of normal. Flow at the gaging
station South Platte River at Kersey was 520 cfs, as
compared to the long-term average of 992 cfs.
Because of the dry conditions in March, stream fiow
in the South Platte was approximately average for the month
of April. This is a major departure from the previous months
this year in which the stream flow far exceeded the average.
It is also a dramatic departure from last year when there
were storms that provided large amounts of rainfall on the
plains and significant snowfall in the mountains raising the
South Platte to fiood stage below the Big Thompson River.

Outlook
A significant aid to the water supply availability
during the month of April was non-charge Colorado Big
Thompson water made available to meet shortages on the
tributaries to the South Platte. This kept a call off most of
the tributaries within the Northern Colorado Water
.onservancy District boundaries.

Administrative/Manaoement Concerns
The snowpack dropped significantly the last few
days of April due to the dry conditions, warm temperatures,
and wind. Because of this drop, the overall average
snowpack conditions were below average by the end of
April. The conditions on the plains were also very dry by the
end of April. This has created some concern among water
administrators that this may be a somewhat dry year in
contrast to previous years. Nevertheless, because of the
excellent storage conditions and bank storage from previous
wet years, the overall water supply outlook for the South
Platte continues above average. As in most years, the
adequacy of the supply this year will be very dependent
upon precipitation within the next month or so.
Irrigation users began taking water along the South
Platte and tributaries toward the end of April. By the last
week of the month. the call on the South Platte was for
irrigation in District 2 above the confluence with the Saint
Vrain. The priority date of the call was 11-20-1885. This is
not an unusual call for this time of year.

Public Use Imoacts
None.

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Hofsetooth Eleven Mile Oleesman Jackson BaIT Lake

.A~. 4J3O Contents '/'J4/3O{()QContents

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