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Aquatic Resources l. Provide for a more detailed evaluation of Ridges Basin Reservoir's expected limnological conditions to better determine whether or not there is justification to provide appropriate facilities to deliver water into the reservoir at an elevation below the thermocline. This could lessen the likelihood of periodically having reservoir water temperatures becoming too warm to support trout and could increase oxygen levels in the reservoir. The evaluation will be completed in coordination with the Service as part of the design data collection activities. 2. Reclamation will develop and implement a monitoring program at Ridges Basin Reservoir to determine the extent ofbioaccumulation of trace elements in fish within the reservoir. The reservoir basin's vegetation will be largely cleared in order to reduce the magnitude of productivity and reduction potential. This, in turn, will limit mercury becoming methylated, the form in which it is available to bioaccumulate within the food chain. Trout will be the only fish stocked. Trout are not at the top of the fish food chain; therefore, they will not be expected to accumulate significant levels ofbioaccumulated trace elements. The program will last two consecutive years and be initiated rwo years after the reservoir is tilled. If significant bioaccurnulation effects are identified, Reclamation will work with the appropriate local, state or federal agencies to either minimize the impact or otherwise offer protection to potentially impacted fish and wildlife species and to possibly post human fish consumption advisories at the reservoir. 3. To minimize downstream stranding of tIsh ,due to the operation of the Durango Pumping Plant. changes in the pumping will be staged in the following manner: An increase in pumping not to exceed 50 cfs per hour (hr) stage decrease and a decrease in pumping not to exceed 100 cfslhr (stage increase) when natural river flows are above 500 cfs. At lower flow, these ramping rates could substantially change river stage. Therefore, when river flows are at or below 500 cfs, increases in pumping will not exceed 25 cfslhr and decreases in pumping will not exceed 50 cfslhr. Seasonal bypass flows will be met (ranging from 125 - 225 cfs). 4. Monitoring studies of project-affected waters on the Animas River will be implemented both prior to and continuing for at least four years after project operations begin (project pumping). These studies will be designed to better define the native fishery, to include better understanding apparent problems with native sucker recruitment, and to monitor trout populations. If it is concluded that the operation of the project is having significant adverse impacts to the downstream aquatic ecosystem, Reclamation will make every reasonable effort to modify project operations to either reduce or eliminate these impacts. The potential impact to native fishes in the Animas River, especially the effects of chronic habitat reduction, may not be directly mitigatable on the Animas River. Investigations should be initiated to determine whether or not fish barriers exist, whether small fish/young-of-the-year fish are significantly lost through entrainment in canals, and whether any significant loss to the trout fishery occurs. The monitoring program will be initiated in 2000 that will incorporate these additional elements into a monitoring study currently being conducted on the Animas River: A firm recommendation for mitigation due to the 5