PROJ00206

• Contract/PO #: C153574
• Contractor Name: Longmont, City of
• Contract Type: Loan
• Water District: 5
• County: Boulder
• Bill Number: SB 88-30
• Loan Projects - Doc Type: Feasibility Study

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The City owns direct flow rights in 13 irrigation ditches off of St. Vrain
Creek. The average annual yield from Longmont's ownership in the 13 ditches is
6459 acre-feet. The City has estimated that the potential transferrable to
potable municipal use is "4608 acre-feet.
The City owns or has partial ownership in 14 reservoirs one of which is
McCall Lake. The 20 year-average annual yield from the City's ownership in
these reservoirs is estimated to be 7484 acre-feet. The minimum 5 year storage
carryover in acre-feet per year for the City's ownership in the 14 reservoirs is
5184.
The average yield of water rights owned by the City of Longmont is 38,265
acre-feet per year which is more than adequate to meet the 2020 water demand for
a high growth scenario of 30,500 acre-feet. However, the safe yield of these
water rights is approximately 24,900 acre-feet which would not meet the 2020
population demand in a high growth scenario. Thus, it is important for the City
to maintain its existing portfolio of direct flow and storage water rights.
Improvements to McCall Lake are required so water can continue to be stored and
released for use by the City.

2. McCall Lake Yields
McCall Lake, which is located in Sections 22, 23 and 26 of T3N, R70W in the
6th P.M. of Boulder County, Colorado was decreed to fill from St. Vrain Creek
and to be used for irrigation and domestic purposes. The decreed capacity of
McCall Lake was 506 acre-feet. McCall Lake has an appropriation date of March
15, 1909 and was adjudicated on June 1, 1926. McCall Lake has a South Platte
River Basin Rank of 1948.
Water commissioner records for releases and storage levels in McCall Lake
were assembled from 1934 through 1987. The average annual release from McCall

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