Gunnison - Overland Reservoir Dam Expansion Restoration_Water Activity Summary

Home Browse Search

The original Overland Dam was constructed in 1905 by a non-profit mutual ditch company founded in 1895. Its capacity was expanded many times between 1905 and 1950 to a maximum storage volume of 6,120 acre-feet of absolute storage decree. The reservoir is located approximately 10 miles north of the town of Paonia in Delta County, Colorado (39.084N 107.646W). In 1957, a section of the main Overland Dam showed signs of distress, subsequently the storage was restricted by the Colorado State Engineer’s Office. In 1986 and 1987 with combined loan funds from the Colorado Water Conservation Board and the U.S. Bureau of Reclamation, the main dam was rehabilitated and the spillway was rebuilt and enlarged in conformance with Colorado dam safety regulations. After rehabilitation, the storage capacity was 5,828 acre-feet which left 292-acre feet of absolute storage decree not stored and 1,051 acre-feet of conditional storage right that could not be stored. The rehabilitation design included provisions for future restoration and/or enlargement projects that would allow storage of the full balance of water rights, yet money was not available at that time to build more capacity. The Overland shareholders continue to pay on these loans. In 1987, the Overland Ditch and Reservoir Company, with additional funds from the Colorado Water Conservation Board, was able to buy out the US Bureau of Reclamation loan at a discounted amount. This shifted dam safety jurisdiction from the Bureau of Reclamation to the Colorado State Engineer which permitted the minimum flood surcharge requirements to be reduced. This allowed for an increase in the normal water storage level by 1.5 feet and provided for storing the remaining 292 acre-feet of the absolute storage and 80 acre-feet of the conditional storage right for a total of 6,200 acre-feet. This increased capacity construction was completed in 1991. There remain 971 acre-feet of 1902 (adjudicated 1920) conditional storage rights beyond the current capacity of the Reservoir. There is both expressed and obvious need for additional storage water in the area served by The Overland. Should The Overland not provide storage capacity for this conditional decree the decree could be lost to the next senior applicant who most assuredly would fall under the 1922 Colorado River Pact and the State of Colorado would lose absolute control of the water forever. In addition, because of its high elevation and location within the headwaters of the North Fork of the Gunnison River, Overland Reservoir is in a somewhat unique position to supply water to a large area in the region. Loss of the ability to store water in Overland would re-allocate use of that water to a diversion at a lower elevation and would significantly reduce the area that can be served by the water. The current proposed dam expansion and restoration project will increase the storage capacity of the reservoir to 7,171 acre feet and allow The Overland to secure the conditional 971 acre feet decree by converting the decree to “absolute” thereby protecting the water forever for the State of Colorado. Sources of water for The Company include: Leroux Creek, Roatcap Gulch, Terror Creek, Hubbard Creek, Elk Creek, and Cow Creek. The Reservoir is located on Cow Creek. The Overland Shareholders own seven direct flow rights with adjudication dates ranging from 1908 to 1954 and total direct flow rights of 214.7 cubic feet per second. The Overland shareholders also hold four storage rights with adjudication dates ranging from 1914 to 1954 totaling 7,171 acre-feet. The most recent yield analysis of the Overland Reservoir drainage basin was completed as part of the loan application documents in 1976. During an 18-year study period, there was sufficient runoff to fill a 7,171 acre-foot reservoir 13 of those years. During three of the five years without sufficient - 2 -