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<br />000719 <br /> <br />Black Canyon of the Gunnison National Park <br />NPS Water Rights Filing <br />Proposed Settlement <br /> <br />Back~round: TIle water right claim filed on behalf of the NPS in January, 200l consists of <br />three distinct parts: 1) base flows, 2) peak flows and 3) shoulder flows. <br /> <br />These can be ordered into a hierarchy of park benefits: <br />· the base flows afford the highest benefit. It is easily argued that the Black <br />Canyon was carved by water and water should be an integral element to the park <br />experIence. <br />· the peak flows afford the second highest benefit. The NPS desires a park <br />whose natural character is preserved. The scouring of riparian vegetation occurred <br />as a natural condition. <br />· the shoulder flows are the least beneficial. These flows are also targeted at <br />removing riparian vegetation and are a "second step" toward this removal. <br /> <br />These same three flows can also be arranged into a reverse hierarchy in terms of social cost: <br />· base flows are the least disruptive to the current water and power delivery <br />scheme. The current operation of the Aspinall Units already allows for the 300 <br />cfs in the Black Canyon. <br />· peak flows are the second most costly. Peak flows mean water is released that <br />bypasses the powerplant and at times that are independent of power and water <br />needs and <br />· the shoulder flows carry the largest societal cost. These flows are measured in <br />thousands of acre feet and are delivered at the "wrong" times with regard to water <br />and power needs. <br /> <br />Settlement Proposal: Base Flows & Peak Flows Carved from Water at "Risk of Spill" <br />1) Base flows: 300 cfs below Gunnison Tunnel <br /> <br />2) Peak Flows: The NPS claim is for one day of peak flows. The NPS understands that <br />riparian scouring occurs within hours, not days Qr we~~?~{Hjs thes119!lld~r flows'uwhich <br />ramptipto-ale--one-day-peakandthen ramp d~~ ~g~in which requires a large volume of <br />water). The concept described below is borrowed liberally from the Glen Canyon Dam <br />"hydrologic triggering criteria". The concept is basically this; water which is at "risk of <br />spill" is identified at a given time during the runoff season. Natural resource management <br />agencies are alerted to this. At their direction, Reclamation produces a man-made flood <br />which matches the timing, duration and magnitude that benefits the natural resources <br />below Glen Canyon Dam. This way, 'no water bypasses the power plant that wasn't at <br />risk to bypass anyway and this water is used for the benefit of natural resources. <br /> <br />Based on the Glen Canyon model, an Aspinall triggering criteria would be developed <br />where: <br />· Peak flows would be limited to "spill" conditions <br />