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<br />decision has been made by the Dolores District to short irrigation <br />supplies in dry years. For the San Juan Basin imports, this amounts <br />to a decrease in diversions of about 3,000 AF. The decrease in <br />return flow is about 15 percent of that value, or 450 AF. However, <br />due to the uncertainty of the solution to the instream flow issue, an <br />assumed decrease of 3,000 AF was applied to the McElmo Creek return <br />flows, reducing it from 25,000 AF down to 22,000 AF. Spread over the <br />irrigation season, this amounts to a decrease of about 10 cfs. <br /> <br />B. Navajo Dam Operation <br /> <br />The SJRIP Biology Committee and the Navajo Dam Operating Committee <br />currently sponsor three joint meetings per year, in January, April, and <br />August. These meetings are open to the public and anyone interested in <br />the operation of Navajo Reservoir is welcome to attend these meetings. <br />The purpose of these joint meetings is to discuss the operation of Navajo <br />since the previous meeting and to come to a consensus on how Navaja would <br />be operated under varying inflow scenarios until the next meeting. For <br />example, the meeting held in January of each year would discuss the <br />operation of Navajo from August through December and would set the <br />release schedule from January through April. The research needs <br />associated with the 7-year research plan are the focus of these meetings. <br /> <br />Several possible future Navajo inflow scenarios are evaluated and <br />releases are planned in response to these inflows. Inflows corresponding <br />to 10 percent, 50 percent, and 90 percent exceedance levels are typically <br />used in this analysis. Since hydrologic conditions can change <br />dramatically, adjustments to planned releases are common. Changes in <br />forecasted runoff are the driving factors in these situations. Changes <br />in releases are coordinated with involved parties. <br /> <br />Downstream flood control constraints were an issue during the past <br />several years, potentially limiting the releases from Navajo Dam. The <br />1991 Opinion contains a provision for a high spring release, which the <br />computer analysis was modeled as a 300,000 AF release during the months <br />of May and June. This assumed a maximum dam release of 5,000 cfs for a <br />1 month period spread between these 2 months. The Corps of Engineers <br />had proposed a draft revised Water Control Manual (WCM) for Navajo Dam <br />to reduce channel capacity to 5,000 cfs from Navajo Dam to Farmington <br />and 12,000 cfs from Farmington (below Animas River confluence) through <br />Shiprock. The Service expressed concern regarding the proposed <br />12,000 cfs restriction at Farmington and after conversations with the <br />Corps of Engineers and on-site inspections (by the Corps), the Corps has <br />decided that they will retain the current WCM (1970) of 16,800 cfs at <br />Farmington, 17,600 cfs at Shiprock, and propose a reduction to 5,000 cfs <br />between the dam and Farmington. <br /> <br />II. BACKGROUND <br /> <br />The hydrology analysis that supports the jeopardy and adverse modification <br />conclusion of the full Animas-La Plata Project is presented in the Project <br />Effects section of the Opinion. The analysis of the full Project looked at <br /> <br />3 <br />