09 ‎(2)‎

• Board Meeting Date: 9/18/2007
• Description: ISF Section - Application of St. Vrain & Left Hand Water Conservancy District ‎(Case No. 1-02CW334)‎ - Pretrial Resolution
• Board Meetings - Doc Type: Memo

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statement, the District reviewed Boulder County's building records and identified homes of 56 of the
69 plan members along Middle St. Vrain Creek that were constructed prior to December 11, 1987.

Replacement Sources to Beaver Creek and South St. Vrain Creek

The District utilizes Beaver Park Reservoir as a source of augmentation water. Beaver Park
Reservoir is located on Beaver Creek, a tributary to South St. Vrain Creek above its confluence with
Middle St. Vrain Creek. According to the District's operations projection, releases from Beaver
Park average 24.6 acre-feet in August, 26.3 acre-feet in September and 18.59 acre-feet in October.
Releases from Beaver Park augment the flow in approximately 2.25 miles of Beaver Creek (on
which the CWCB has a 1.5 cfs ISF water right), approximately 7 miles of South St. Vrain Creek
from Beaver Creek to Middle St. Vrain Creek (on which the CWCB has an 8 cfs ISF water right),
and approximately 9 miles of South St. Vrain Creek (on which the CWCB has ISF water rights
ranging from 4 cfs to 20 cfs). Thus, Beaver Park Reservoir releases for augmentation of the
District's depletions in the greater St. Vrain basin during late summer and fall provide an overall
benefit to over 18 miles of the river system, which contains numerous CWCB ISF water rights.

Left Hand Creek and James Creek

Based on the current augmentation plan membership, the total depletions in the Left Hand basin are
23.83 acre-feet per year. Approximately 37% of these depletions are located downstream of the
Lake Ditch headgate, and therefore, downstream of the Left Hand Creek and James Creek ISF water
rights. The table below provides the average daily depletions by month of the District's
augmentation plan members affecting the ISF reaches.

Ave."age Daily Depletions by Month to each ISF Reach

Month Left Hand Creek James Creek above Left Hand Creek
above Spring Gulch Left Hand Creek below James Creek
Case No. 86CW301 Case No. W-9379-78 Case No. 86CW342
(cfs) (cfs) (cfs)
January 0.0026 0.0002 0.0059
February 0.0029 0.0002 0.0067
March 0.0026 0.0002 0.0060
April 0.0027 0.0002 0.0062
May 0.0029 0.0107 0.0273
June 0.0032 0.0207 0.0472
July 0.0031 0.0207 0.0472
August 0.0031 0.0164 0.0386
September 0.0030 0.0143 0.0346
October 0.0028 0.0049 0.0158
November 0.0027 0.0002 0.0062
December 0.0026 0.0002 0.0060

Depletions to Left Hand Creek above Spring Gulch and depletions to James Creek also accrue to
Left Hand Creek below James Creek. In addition, there are users located on Left Hand Creek in the
reach between Spring Gulch and the James Creek confluence which cause depletions only to the
reach of Left Hand Creek below James Creek. Thus, the amounts shown in the table are not additive
and the total equivalent impact to the Left Hand Creek and James Creek ISF water rights is 0.021
cfs. In addition, the Town of Ward's depletions represent 13.8% of the depletions to Left Hand
Creek above Spring Gulch (which also impact Left Hand Creek below James Creek). As the Town
of Ward has purchased shares in the Left Hand Ditch Company, the District believes that the Town

Flood Protection. Water Project Planning and Finance. Stream and Lake Protection
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