On June 1, 2000, an historic agreement negotiated by counsel for the District was executed for the benefit of the Upper Gunnison Basin. The agreement is the “Agreement Among the United States, the Colorado State Engineer, the Colorado River Water Conservation District, and the Upper Gunnison River Water Conservancy District for the Administration of Water Pursuant to the Subordination of Wayne N. Aspinall Unit Water Rights within the Upper Gunnison River Basin” (Subordination Agreement). The Subordination Agreement formalizes the commitment made by the United States during the planning of the Aspinall Unit to allow depletion of the Aspinall Unit Rights up to 60,000 acre-feet per year by in-basin water users so that construction of the Aspinall Unit would not interfere with future water development in the Upper Gunnison River Basin. The Subordination Agreement protects diversions under water rights in the Upper Gunnison Basin which are junior or equal in priority to the Aspinall Unit from being curtailed when a call is being made by the Aspinall Unit, subject to certain limitations.

Specifically, the Subordination Agreement provides that the United States will subordinate the water rights of the Aspinall Unit to up to 10,000 acre-feet of annual water depletions in the Gunnison River Basin drainage between Crystal Dam and Morrow Point Dam, 10,000 acre-feet of annual depletions in the drainage between Blue Mesa Dam and Morrow Point Dam, and 40,000 af of annual depletions in the drainage above Blue Mesa Dam. The subordination of Aspinall Unit rights under the agreement is applicable only to water rights with priorities junior or equal to the Aspinall Unit water rights and which are exercised for beneficial use in the Upper Gunnison Basin. The Taylor Park Reservoir refill is included among the water rights qualifying for subordination.          Appropriate uses of the depletion allowances include evapotranspiration, reservoir evaporation, irrigation, industrial, domestic, and other beneficial uses. Water which is diverted and ultimately returns to the stream and then is available for use pursuant to the Aspinall Unit rights is not considered a use of the depletion allowances, nor are non-consumptive uses such as instream flows. Undecreed diversions and depletions which exceed the limits of the subordination allowances are not afforded protection under the Subordination Agreement.

The Subordination Agreement requires the District, in collaboration with the Colorado River Water Conservation District (River District), to obtain an appropriate decree to enable the Colorado State Engineer to effectively administer the agreement in accordance with Colorado law. To comply with that requirement, the Districts adjudicated a plan for augmentation (Case No. 03CW263).

Beginning in 2002, as required by the Subordination Agreement, the District and the River District file an annual report with the Bureau of Reclamation indicating the amount of diversions and depletions qualifying for the subordination in the previous water year. This report includes the depletions that occur from water rights with priorities equal or junior to the Aspinall Unit priority of November 13, 1957.