K.W. Emerson Inc. outbid one of EID’s usual contract winners, Syblon Reid, to upgrade a spillway and tunnel entrance near the short section of canal that empties into Forebay Reservoir in Pollock Pines.
The winning bid was $1,322,261, which was a mere $76,739 lower than the second highest bid from ProVen Management Inc., but more than $360,000 lower than the Syblon Reid bid.
The engineer’s estimate was $1.7 million.
The bid was awarded on a 4-1 vote of the El Dorado Irrigation District’s Board of Directors Aug. 27. Director Alan Day was the no vote, saying he wanted to delay the project for a year.
The project has three elements to be executed by the contactor:
1. Extend the portal of 14-Mile Tunnel east to allow for a trash rack that will be three times wider and will have space above for a small loader to pick up trash from the rack. Currently trash is removed by hand.
2. Spillway 46 east of the tunnel entrance will be upgraded “to have a full canal spill capacity of 160 cubic feet per second,” according to senior engineer Mike Brink. This spillway will be electrified so that it can be part of the remote control system in place on the rest of the 22 miles of canal and flume. The channel where the spillway releases water in emergencies will be armored to reduce erosion. The district already bought the two slide gates for the spillway.
3. About 200 feet of canal downstream from the spillway will be repaired and earth slope above it will be stripped and stabilized. Large boulders have fallen into the canal from the slopes above this section and will be removed.
After the contractor completes the work EID construction crews next year will then go in and remove Spillway 47, which is nearest the tunnel entrance. Spillway 47 is dilapidated and spills onto loose volcanic soil and no rocks. EID crews will replace this spillway with wooden flume. Improving Spillway 47 would have cost $3.4 million, EID engineers estimated.
Total cost for this year’s project, which will take place in October when the canal is dewatered and the powerhouse shut down, is $1.5 million. That includes construction management and inspection costs by EID of $121,000 and inspection and testing by Carlton Engineering for $14,000 plus $132,000 for contingencies. Those are all costs assigned to capital improvement expenses.
The environmental documents were approved by the board in April.
Last year the board spent $325,000 to design this project, which included $189,700 for Carlton Engineering.
Spillways are placed along the 22-mile conveyance system in case blockages back up water in the canal. The spillways prevent the canal or flumes from spilling uncontrollably.
Canal flow is monitored by computer as well as levels at the four manmade alpine lakes that feed into the South Fork of the American River, where a diversion dam near Kyburz catches the dam releases and shunts the water into the canal and flume system.
The system is called Project 184 by the Federal Energy Regulatory Commission, which requires and approves the spillway improvements. Water from the canal goes to Forebay Reservoir where it is sent to the 21-megawatt Akin Powerhouse. Another 15,080-acre feet is sent from Forebay to Water Treatment Plant No. 1. That consumptive water was designated in 1919, but the water right predates 1914 and is therefore out of reach of state control. An additional 17,000 acre-feet of consumptive water comes from Project 184.
Also approved Aug. 27 — unanimously — was a $64,000 contract to GEI Consulting to design a new outlet valve for Blakely Dam and Resevoir in Camino. The total project is funded for about $277,000.