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The Water Supply & Storage Company Agenda Item l lb January 20, 2009 (UPDATED JANUARY 28) Page 4 of 6 $5 to $6 million dollars. It is a difficult work site which complicates the prospect of boring a tunnel including: the tunnel site is at 10,200 feet elevation; there is steep mountainside access; 20 miles away from power grid; NPS prohibits wasting material within the Park; a full environmental impact study would be required; and there is no suitable housing for the work force near. A Third Pipe alternative -The Company considered excavating a new trench immediately adjacent to the two temporary pipes installed in 2003 and the installation of a third pipe. The pipe would be identical to the two pipes installed previously and would increase the capacity of the system through the breach zone by 50%. Widening of the bench into the mountainside would be difficult and expensive due to the steepness of the terrain. Plate Arch pipe alternative - (SELECTED) This includes the removal and replacement of the two temporary pipes with a large corrugated galvanized steel plate arch pipe. The new plate arch pipe would be assembled on site and installation would not require widening of the existing rock bench. A single conduit eliminates the potential for clogging due to the obstruction created by multiple pipes. This alternative is somewhat more expensive than other alternatives and may cause disruption to ditch operations during construction; however it is the best solution to the problem. Final design plans will soon be underway and construction may start in the summer or fall of 2009. Kluwer Reservoir Outlet Project -Alternatives Considered No Action alternative -Because of the imminent danger of road failure and collapse of the concrete retaining walls into the pipe and headgates, a No Action alternative is infeasible. The damage would require an abandonment of one or more reservoirs. A void beneath the northbound lane has caused the County to close the unsafe road. Since this is the only access to the homes located in the area, this is not an option. Repair of Road and Water Related Facilities alternative -The County and Company considered repairing the road and water related facilities; however, the age, condition and height of the concrete retaining walls were beyond repair. Engineers representing both parties agree that repairs would be more expensive than the complete replacement. Most of the water components have reached the end of their useful life. A future failure of those components could require another complete excavation of the road and embankment. Remove and Rebuild Water Facilities and Road Embankment alternative - (SELECTED) This alternative requires a complete demolition and reconstruction of the existing road and water related facilities. The existing concrete retaining walls, headgates and pipe will all be removed. The new embankment will be constructed from on-site material except for a new clay core and sand filter, as required by SEO. The total Outlet Project cost estimate is $617,000. The Company has agreed to pay for a schedule of construction line items that total $318,000. The County anticipates bidding construction in February and beginning construction in the spring of 2009.