Utica Water Conveyance

November 2009 Maintenance Report
2009 Annual outage report
Flume # 4 and Canal Repairs

The annual maintenance outage for Utica Power this year was 30 days long, instead of the usual 7 to 8 days. The need for this long of an outage was primarily due to the large scope of work to be performed on Upper Utica’s Flume #4, located just off Canyon View Road in Avery. The additional amount of time allowed the flume maintenance crew to make the repairs needed on Flume #4, a separate crew to make repairs on the canal and ditch system, and another crew to make repairs, perform scheduled maintenance and install upgraded components to both the Murphys and Angels powerhouses.

Six additional employees were hired to help with the workload scheduled to be performed this year on the flume/canal system – Flume #4 repair and gunite and rock repair of the ditch and canal.  As in years past the Cal Fire inmate crews helped 22 days during this outage which greatly contributed to staying on schedule.  The first work day began on October 19th at 7:00 a.m. as the water had been gradually reduced the night before to allow the flume to be de-watered by the time the work crews arrived.  CDF crews and a temp hire also began the long process of patching large sections of gunite on this day under the supervision of a UPA operator.

Each of the four weeks of work consisted of removing the old section of flume, raising the grade to achieve a more satisfactory flow, and repairing the appropriate section in order to resume the flow the water each weekend thus replenishing all reservoirs to continue providing water for consumption along the system.

The overall length of this repair was 492 feet from start to finish, thus being one of the largest non-emergency outages to-date for Utica Power Authority.  Proper protocol for dewatering, ramping rates as required by the California Department of Fish & Game, and maintaining minimum flow requirements were all strictly adhered to.  As many fish as possible were collected and relocated to the larger deeper pools, which resulted in a very satisfactory percentage of these fish making it through the entire process.

Roughly eight boxes were removed and repaired or replaced each week due to the efficient and skillful work of all involved.  Preplanning the logistics of transporting the large amounts of lumber that had to be staged and leaving the least amount of impact on the surrounding areas as possible was an important contributing factor to the success of this repair work.

All upper material on this flume was completely replaced as well as new aluminum lining and the reconstruction of Waste Gate #1.  The re-established grade of this flume now makes for a much improved flow and less weight being carried by this flume which makes it more efficient and safer as well.  All old wood was put in open spots on the mountainside and control burned by large CDF crews to ensure the safety of the surroundings.

Large portions of gunite were repaired improving the system both mechanically and aesthetically.  Over 48 tons of riprap was added to the system this year in several spots along the system, greatly reducing erosion concerns in specific areas.  Ten pallets of mortar and concrete were applied as well, capping large areas of erosion.  Cracks and small holes along the areas designated for repair were patched.  All concrete/mortar work was stopped one full day prior to adding water to the system prior to the weekends in order to insure no material/contaminants were washed down the system and into the holding reservoirs.

The sections of canal addressed this year were from Flume #7 to Flume #9, Flume #10 to the wildlife crossing, and Waste Gate #9 to Waste Gate #10.

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