WSP00432

• File Number: 8441.700
• Description: Colorado Big Thompson Project - Annual Operating Plans
• Basin: South Platte
• Water Division: 1
• Date: 1/1/1990
• Title: Annual Operating Plans - Colorado Big Thompson Project - Water Year 1990-1991
• Water Supply Pro - Doc Type: Report/Study

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Lake Gra~by at only 26 percent of average, Green Mountain at 35 percent of
average, land Lake Estes and St. Vrain at only 17 percent of average. The
following' individual precipitation stations within the Project recorded very
low amou~ts in June.

Station

Amount Recorded. June 1990 (Inches)

Rank in Yrs. of Record

Allenspark
Breckenri:dge
Climax
Di 11 on
Estes Park
Flatiron'
GL6SSW
GLlNW

.31
.36
.51
.38
.34
.31
.29
.47

3rd lowest in 45 years
3rd lowest in 43 years
5th lowest in 41 years
7th lowest in 57 years
8th lowest in 81 years
4th lowest in 32 years
5th lowest in 42 years
4th lowest in 50 years

July through September precipitation was above normal on all watersheds.
The Green! Mountain watershed recorded 124 percent of average precipitation
for July!through September. A total of 5.77 inches of precipitation was
recorded vn the Willow Creek and Lake Granby watersheds from July through
Septembe~and this was III percent of average. Precipitation in the Lake
Estes area was much above average for the 3 months, at 144 percent of
average. : The 4.24 inches of precipitation recorded at Lake Estes in July
was the fourth highest in 81 years of record.

For water year 1990, the _ minimum recorded temperatures were .140F at
Green Mountain Reservoir on January 4, -220F at Lake Granby on January 4, and
-20oF at Uake Estes on December 22. Overall, winter temperatures were above
normal for the water year, except for a cold December.

Temperatures were 2 degrees above 'normal for April and temperatures were
4 degrees! below normal for May. June' temperatures were much above average
with fiv~ new record maximum daily temperatures set in Denver and one
maximum ~aily temperature record tied. The new maximum daily recorded
temperatures for Denver were 930F for June 4, 990F for June 25, and 1020F for
June 27, June 29, and June 30.

The heat, wave continued into early July, with record maximum daily
temperatures of 1020F being recorded for July 1 and July 2 in Denver. The
last 3 we~ks of July recorded below or near average temperatures. August
and Sept~mber daily temperatures were mixed, with overall monthly
temperatures being below normal. New maximum daily temperature records
occurred ~n Fort Collins on August 30 and September 13, with 960F and 970F
being rec~rded respectively. The 970F temperature recorded on September 13
was the highest September temperature ever recorded in Fort Collins.

The maximum recorded temperature was 8rF on July 1 at Green Mountain
Reservoir; The maximum temperature at Lake Granby occurred on June 30 and
July 2 and was 860F, and Lake Estes recorded a maximum temperature of 900F
on June 29.

Alva B. A~ams Tunnel (Adams Tunnel) diversions totaled 216,700 acre-feet
(92 percent of average) for the water year.

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