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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b. Future Water Requirements
The 1986 St. Vrain Basin Reconnaissance Level Study made predictions on
future water demand up to the year 2020. Projections were made for low, medium
and high growth scenarios.
Table 5.3 shows the Longmont water demand forecast for the years 1990, 2000,
2010 and 2020. The forecast was determined by estimating the demand from single
family residences, multiple family residences and commercial users and then
adding an additional 15 percent to account for system losses and uses. The
demands were based on average weather conditions. The 2020 Longmont municipal
water demand for low, medium and high growth scenarios is 18,700 acre-feet,
22,700 acre-feet and 30,500 acre-feet respectively.

B. Existing Water Supply
1. Yield of Water Rights Owned by Longmont
The City of Longmont owns numerous direct flow and storage rights on St.
Vrain Creek and Dry Creek. In addition, the City owns groundwater rights and
Colorado Big Thompson and Six Cities project water. A complete list of direct
flow and storage rights owned by the City along with the average historic yield,
average annual available for potential transfer to potable municipal use and
safe yield (1954) of these rights is summarized in Table 5.4.
The average annual yield of the City's pipeline decrees, groundwater rights
and project water is 40,393 acre-feet. These rights include the Longmont North
and South Pipeline which feed directly into the City's water treatment plants
located below Lyons; 1 decreed groundwater well, 21 conditionally decreed wells
and Colorado Big Thompson and Six Cities project water. Of the 40,393 acre-
feet, the City has estimated that 26,180 acre-feet in an average year can be
used for potable municipal use.

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