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40 Winter releases from Navajo Dam have maintained flows at or above 500 cfs through winter months during most years since 1962 in the San Juan River at Archuleta. The median pre-dam (1931-1962) winter flow (November through February) at Archuleta was about 250 cfs. This increase in base flow at Archuleta, combined with increased irrigation return flows in the winter, has provided a median flow below Shiprock of over 1,400 cfs during the post-dam period compared to a median flow of 660 cfs pre-Navajo Dam. Releases from Navajo Dam of approximately 300 cfs would produce an average winter base flow of approximately 650-700 cfs near Bluff, Utah. The San Juan Recovery Implementation Program's Biology Committee finds it necessary to test a winter low flow in critical habitat for Colorado squawfish and razorback sucker, prior to making a final recommendation on minimum winter flows. The hydrographs provided by Reclamation that illustrate implementation of the reasonable and prudent alternative, show winter releases from Navajo Dam of 300 cfs. Therefore, the Service finds it appropriate to provide winter test flows of approximately 300 cfs during the research period. The winter low flow test as required in Element 2 above would require releases from Navajo Dam to be ramped down from 500 cfs to about 300 cfs in more than 6 hours, but less than 24 hours. Flows would not be allowed to fall below 500 cfs in endangered fish habitat, as measured at the Shiprock and/or Four Corners gage. The 4-month test would allow some assessment of biological response and should be replicated in a subsequent year, to be valid. In 1991, it was determined that the minimum study period necessary to conduct the required studies was approximately 7 years. Any inability to deliver the flows under the third element of the reasonable and prudent alternative would likely prolong the research period. To date, the range of flows necessary to complete the research have not been available for testing and not all of the releases have been synchronous with the peaks of the Animas River, as requested. During the research study period, it was anticipated that Navajo Dam would be operated under a variety of scenarios (wet, average, and dry) to mimic a natural hydrograph. However, to date, a dry year scenario has not yet been available. Because of this, all planned research can not be completed. The objective is to re-create a high spring peak flow providing a gradually ascending limb followed by a gradually declining recession limb to low, stable flows throughout the summer, fall, and winter. The Service and the biological experts believe that this is the best opportunity available to bring the endangered fish back from the brink of extirpation in the San Juan River. By returning the river to a more natural hydrograph and raising the spring peak flows, the Service believes there will be an increase in reproduction and recruitment of the endangered fish in the San Juan River. This operation of Navajo Dam is the most important feature of the reasonable and prudent alternative both for the research period and the long term. In order for there to be an annual average depletion of 57,100 acre-feet of water from the Project, there must be a guarantee that, based on the results of the research program and dependent upon prevailing hydrology, Navajo Dam will be operated to mimic the natural hydrograph for the life of the Animas la-Plata Project. Under section 7(a)l, Reclamation has agreed to reoperate