Longmont 1996 WCPlan

• Project Type: Water Conservation Plan
• Project Name: City of Longmont Water Conservation Plan
• Title: Water Conservation Plan
• Date: 7/3/1996
• County: Boulder
• County: Weld
• Water Conservation - Doc Type: Complete Plan

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WATER SUPPLY

The City of Longmont owns a varied and extensive portfolio of water rights which includes
direct flow and storage water rights out of the 5t. Vrain River (collected in the 5t Vrain Basin
Watershed), water rights owned in shares of numerous ditch and reservoir companies, the
Colorado Big-Thompson Project, and the Windy Gap Project.

The City's water supply, in an average year, will meet the needs of a population of 72,000. The
City's population as of 12-31-95 is 57,208. The Raw Water Master Plan outlines water
management alternatives (including water conservation) to increase the City's water supply to
meet the needs of the projected population through buildout of the Longmont Planning Area.

Raw water storage is available in Longmont Reservoir, located northwest of Lyons; Copeland
Lake, purchased in 1913; Ralph Price Reservoir and Button Rock Dam, completed in 1969; and
majority interest in Union Reservoir, purchased in 1987. Additionally, the City owns shares in
Burch Lake, Terry Lake, Clover Basin Reservoir and Independent Reservoir. Total raw water
storage capacity is currently 26.190 acre feet.

As a condition of annexation of land to the City of Longmon!, ownership of all historic water
rights associated with the land is transferred to the City. As a condition of subdivision of lands
annexed to the City, if historic water rights transferred yield less than three acre feet of water for
each acre of land subdivided, the deficit may be satisfied by the transfer of additional water rights
or payment of the current per acre foot cash-in-lieu fee. The cash-in-lieu fee is used by the City
to purchase additional water rights.

The total raw water supply for 1995 was 60,469 acre feet Only that portion of the total water
supply designated as municipal may be treated for drinking water use. FOL1995, 64% of total
raw water supply (38,521 acre feet) was available for municipal use. The City's Water
Resource~ Division pursues conversion of agricultural water rights to municipal use through the
Water Court on an on-going basis.

Thirty-seven percent (37%) of Longmont's municipal supply came from water carried over from
the prior year and ~tored at Ralph Price Reservoir. Winter water is supplied almost totally from
Ralph Price Reservoir. The amount carried over from one year to the next is one of the most
important sources of guaranteeing a sufficient water supply. Completion of the City's connecting
line to the Carter Pipeline (scheduled for 1999) will provide additional winter water.

In 1995,46% of the municipal supply was used to supply potable water, 4% was used for park
irrigation and agreements, and 50% was carried over in storage for use in 1996. Of the water
carried over in storage, 4,627 acre feet remains in Carter Lake and 14,668 acre feet remains in
Ralph Price Reservoir.

The City's three water treatment plants have a combined treatment capacity of 50 million gallons
per day. The wastewater treatment plant has a hydraulic capacity of 11.5 million gallons per day.

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