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001G70 Revised Supplemental Draft Environmental Assessment-Chapter 2-Altematives constructed road paralleling the Colorado River along the right riverbank from the Interstate 70 bridge to the Price-Stubb Diversion Dam. Construction staging and material storage would be on adjacent vacant land owned by E.R. Jacobson and CDOT. Construction access is limited near the dam because of its proximity to the railroad tracks and Interstate 70. A cofferdam would be used to direct the river around the construction area and river flows would not be reduced. Before construction, Reclamation and the contractor would obtain necessary approvals required by the Clean Water Act. Reclamation would request Section 404 authorization under Regional General Permit No. 057 for projects that benefit recovery of endangered fishes. If discharging water for construction dewatering is needed, the contractor would obtain a Section 402 permit. Reclamation would also coo:rdinate construction activities within the 100-year floodplain with Mesa County. Construction would be scheduled during low river conditions in the fall and winter of 2005-2006. Reclamation recently constructed a similar passage at the Grand Valley Project Diversion Dam and estimates the construction costs of this alternative to be about $4,300,000. Operation, Maintenance and Replacement Measures The Service would operate the fish ladder from April through October of each year. They would monitor native and endangered fish use ofthe ladder. An agreement among Palisade and Mesa County Irrigation Districts, the Service, and the Recovery Program would define operation and maintenance, and replacement responsibilities. Construction would not begin until operation, maintenance, and replacement funding mechanisms were agreed upon and the agreements signed. Permission would also be obtained from all affected land owners for perpetual access and use of the site for operation and maintenance. Long-term operation and maintenance cost are estimated to be $15,000-$25,000 per year. The Recovery Program or the Service would fund all activities for the fish ladder, with no costs to local water users. Water Supply for Fish Ladder Because of downstream senior water rights, a flow of at least 520 cfs is present iri this reach of the river under all but the most severe drought conditions. The Service also has up to 37,650 acre-feet of storage water available from upstream reservoirs for endangered fish uses in drought years. About 25 cfs of Colorado River flow would be needed to operate the fish ladder. An additional 75 cfs would be used to provide attraction flows necessary to direct fish to the fish ladder entrance. Ifthe Jacobson Hydro No.1 Project were independently constructed, the power plant's tailrace could also provide the necessary attraction flow. 11