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"'""- - . The Proiect The CC Ditch Company currently diverts water from the San Miguel River through a concrete diversion structure located on the north bank. Water is di~ected to the structure from a five foot high concrete dam . placed perpendicular to the flow of the river. The water passes through a three foot high by twelve foot wide orifice controlled by a hand operated steel cylindrical slide gate. The proposed modification to the structure is designed to (1) improve the existing diversion structure, (2) develop a stable pool/drop rapid in the channel that will facilitate upstream fish rhigration and create a reasonably safe boating experience, (3) return the river channel to its na~ural morphological dimensions, and (4) improve habitat with native willow plantings. The project will fortify the existing structure and potentially reduce sediment into the Highline Canal. The five-foot drop created by the existing diver~ion dam will be spread out over a length of 180 feet with 3 ft. to 6 ft. average diameter boulders grouted ir place. The downstream side of the existing 115- foot long dam will be filled with boulders to, and slightly above, the height of the existing concrete structure, which will not be removed. The constructed step/pool rapid will be 20-feet wide with a series of six pools each approximately 30-feet long with a total drop of 18 inches. Each pool will have a 10-foot by 1 O-foot scour hole designed to dissipate energy and allow fish to congregate before moving to the next pool. The placement of the centerline of the pool/drop structure will align with the existing centerline of the channel above and below the existing dam. The project will help return natural channel dimensions to the area adjacent to the dam and concentrate low river flows into one channel instead of spreading it out over 115 feet. High flows will continue to be spread out over a longer length, similar to a natural channel, but will have that energy dissipated over a broader area. Three boulder j-hook structures will be constructed upstream of the diversion to help redirect bedload to the center of the channel, reduce sediment into the ditch, stabilize the north bank of the river, improve . aquatic habitat and help direct boaters away from the headgate. Additional rock will also be placed along the upstream side of the dam to reduce erosion of the existing concrete structure and create a transition to natural channel dimensions upstream. To further improve habitat, willow cuttings will be planted in between rock voids along the south side of the river. Other Fundin!! Sources The total project cost is $307,000. The CWT, TNC, TV and the San Miguel Watershed Coalition have requested funding from the Southwestern Water Conservation District and from Tri-State Generation and Transmission in the amounts of$40,000 and $10,000 respectively, and have obtained a $25,000 grant from the National Fish and Wildlife Foundation for the project. A CCC Ditch Company member intends to donate $160,000 worth of stone materials for the project. Discussion As part of its cooperative effort with the CCC Ditch Company, TNC, TV and the San Miguel Watershed Coalition, the CWT is requesting a non-reimbursable investment from the Board for less than 25% of the cost of this project. The CWT believes that this project represents an innovative effort that is consistent with the CWCB's policies and objectives, and would demonstrate a novel approach to reconciling historically competitive interests. The stretch of river targeted by this project represents a unique combination of private ownership and public land management. Over 60% of the San Miguel watershed . is federally owned land, and over 90% of the river and its major tributaries are open to the public. Still, Flood Protection. Water Project Pl~nning and Financing. Stream and Lake Protection Water Supply Protection. Conservation Planning