WSP07897

• File Number: 8220.126.D
• Description: San Miguel Project
• State: CO
• Basin: San Juan/Dolores
• Water Division: 4
• Date: 12/20/1988
• Title: Flow Measurement and Operating Records Data Memorandum
• Water Supply Pro - Doc Type: Report/Study

-
,

.~
~

.-.,
'-

Operating Records

To obtain more detailed information regarding operating procedures, data forms for recording
the operations at Gurley Reservoir, Gurley Ditch Diversion Structures, Lone Cone Reservoir,
and the Ulylands System for the 1988 season were developed for use by the Farmers' Water
Development Company, the Lone Cone Ditch and Reservoir Company, and the Lilylands Canal
and Reservoir Company. These forms are displayed in Appendix A, Data Forms. The forms for
the Gurley and Lone Cone systems were discussed with representatives of both systems in a
meeting in Norwood On May 10, 1988. An agreement was reached between the two
organizations that all records for both systems would be kept by Mr. Wilton Barrett, ditch rider
for the Gurley system. The form for the Lilylands System was discussed with Mr. William Bray,
who agreed to maintain the records, in a meeting in Redvale on May 11, 1988.

The data recorded for the 1988 irrigation season for Gurley Reservoir is given in Table 5, for
Lone Cone Reservoir in Table 6, and for the Lilylands System in Table 7. Rating equations
developed as part of the flow measurement program were used to estimate inflows from
observed stages at gages upstream of the Lone Cone and Gurley Reservoirs. Stage discharge
relations for 6' and 10' Parshall Flumes were used to estimate outflows from the Lone Cone and
Guriey Reservoirs, respectively. Due apparently to the low runoff rates of the season, no
operating adjustments and few observations were reported at any of the diversion structures in
the Gurley Collection System.

Summarizing the records kept for the Lone Cone Reservoir, data for inflows, outflows, and
reservoir storage were received covering the period from May 13 to August 7, 1988.
Observations were made virtually every day through the month of June. Through July and early
August the frequency of observations progressively declined to basically a weekly schedule.
Observed inflows ranged from a maximum of approximately 41 cfs on May 18 to a minimum of
approximately 3 cfs on August 7. Observed outflows ranged from 41 cfs on several occasions
to 0 cfs. The reservoir never filled completely, with the maximum reservoir stage observed at
20.5 feet on May 21, which corresponds to an approximate storage volume of 1400 acre-feet.

Summarizing the records kept for the Gurley Reservoir, data for inflow, outflows, and reservoir
storage were received covering the period from May 13 to July 27. Observations were made
virtually every day through the month of June. In early July, inflows were turned out of the
reservoir to empty it by early August for repairs. Consequently, the frequency of observations
during July declined to a rate of two to three times a week until the reservoir was drained.
Observed inflows ranged from a maximum of approximately 350 cfs on M"IY 18 to a minimum of
approximately 37 cfs before inflows were turned out entirely. Based on the characteristics of
the diurnal fluctuation pattern of the Gurley Ditch and the time of observation of the peak stage,
the instantaneous maximum peak of the season was probably about 440 cfs in the early
morning hours of May 18. Observed outflows ranged from a maximum of approximately 150
cfs on July 13 to a minimum of approximately 57 cfs on July 2. The reservoir never filled
completely, with the maximum reservoir stage observed at 53.0 feet from May 20 and 26, which
corresponds to an approximate storage volume of 7780 acre-feet.

9