2001 Darby Fire

Wildfire destroys large sections of UWPA flume system cutting off water supply to 10,000 people in Murphys and Angels Camp

people affected
acres burned
flume replaced
repair cost

Lessons learned from the Darby Fire

Steps we can take to prevent this from happening again. 

September 5, 2001 -
At 5:30 pm, on the evening of September 5th, 2001, a wildfire swept up the Calaveras County side of the Stanislaus Canyon. Utica Power Authority (UPA) immediately began water shut-down procedures in advance, knowing the fire would quickly reach the area of the flumes and would destroy a lengthy portion of the overland water transport system.
September 7, 2001 -

By September 7, all of ¾ Mile Flume had been completely destroyed aside from the aluminum lining that had melted into puddles. This meant the loss of ability to bring water to the communities from Murphys to Angels Camp.

The fire had damaged approximately 33,632 square feet of gunite canal and 735 linear feet of wooden flume sections, walk boards, dump gates, deer crossings, and wooden helicopter pads. In order to be able to reestablish a water supply back to the communities using the overland pipe system while Flume 14 was being replaced, the UPA team would first need to immediately repair flumes 9, 10, 11, and 13.

September 8, 2001 -

A staff meeting was held at the UPA office to evaluate damaged areas, and discuss how the repairs would be handled. The UPA men would be assigned to new emergency repair duties. UPA was also fortunate to get two individuals from Tuolumne Irrigation District, who volunteered their time to help develop a plan of repair.

Because UPA did not have an accounting system in place to support the accounting needs of these emergency crews, the CCWD was paid to act as a Temp Agency to hire temporary CDF crews and handle payroll. Once this labor force method was agreed upon, the crews were contacted and then sent to CCDWD to sign up for the project.

September 9, 2001 -
Before the repairs to the flume system could begin, the crews first needed to remove the burned-out materials from the work sites. The gunite and earth ditches needed to be repaired as well, due to the debris caused by CDF crews fighting the fire. Finally, there were a lot of burned trees that had fallen across the ditch and these needed to be cut up and removed.
September 10, 2001 -

Flumes 10 &11 were the first areas where debris and burned-out materials were removed from. After relocating all the mud blocks and footing locations, the crews began rebuilding the foundation bents.

Overland Water Pumping System - The Site

It wasn’t long after repairs began on Flumes 9, 10, 11, & 13 that the approval came for installing the overland piping system – so the crews that weren’t helping install the pumps worked on repairs on Flume 15. Flume 15 was crucial for the emergency water delivery system since it would be used as the outlet area for the 10-inch overland pipe system, and was installed just ahead of Flume 13, where we had a steel flume section that had survived the fire. Located just past the steel flume was an automatic siphon, which would allow us to maintain a constant level of water for the pumps.

The Pumps & Their Pipes

Flume 15 remained partially intact, but still had some structural damage in regard to the foundation bent structures. Additionally, the flume had dropped about 2 feet in elevation, so it needed to be raised and repaired before the pumps for the overland pipe system became operational

It was determined that it would take four 200 horsepower, high pressure pumps, with six-inch discharges to pump the 350-foot head of water. The engineers wanted to ensure that this system could continually carry water while the flume was being repaired. They decided to use six-inch discharge pumps, two each, into ten lines. This way, if one pump was to fail or was down for maintenance, we could still maintain the other two-pump system. Approximately 5,000 linear feet of ten-inch pipe would be installed over 2,500 linear feet of land.

Job Well Done

UPA’s planning and attention to detail served them well as the emergency overland water pumping system performed its task from September 2001, though the long winter and into the hot, dry summer. About three weeks away from completion of Phase II of Flume 14 reconstruction, around June 18, 2002, the pumps began failing. With so little time left to complete the reconstruction, the crew’s worked overtime to finish. They poured concrete on Saturdays and Sundays and worked 10 hours a day, 6 days a week. Two of the pumps finally failed by June 20th, after having them running day and night for over nine months. Rather than perform costly repairs, the team decided to “pull the plug” and reestablish their water system again. Within a twenty-four-hour period, all water through the system was shut off, the pumps were removed from the site, the plug from the ditch was removed, and the area was reclaimed to Forest Service specifications.

Clean Water at Last

Once the plug was removed from the ditch system, major flushing needed to take place. There was lots of debris remaining in the ditches from the fire and from the winter runoff. A tremendous amount of silt and debris had to be dump-gated out and was flushed into our forebays and afterbays.

Once everything was working properly, the pump and pipe system needed to be disassembled, removed from the site, and its entire area of use returned to pre-use condition per Forest Service and Private Land Lease contract. It took approximately two days to fill in the area where we had originally dug out the bank to create a location for the pump pad, re-seed it, and utilize the matting to hold the seed in place. Following that, the culvert that allowed the overland pipes to pass under the road was removed. Next, the overland pipe itself was disassembled and ready for removal from the site, along with the road bridge, concrete hold-downs, rebar stakes and all construction materials. This took place in the three weeks following the start up of the system.

Road Reclamation

After the pipe was completely removed and transported off site, the team needed to do some reclaiming to the road into Flume 14 at the turnaround site. They had adapted a Cat (Caterpillar) to help with this work, as well as a backhoe to remove some of the culverts that had been temporarily used, and to install some of the water bars. Ted Franks from the Forest Service worked with the crews during the two weeks from June 23rd until the second week in July in regards to reclaiming and filling all of his requirements. They received a letter from him that stated “everything was taken care of to his satisfaction”.

Rebuilt flume system gets back to work

Union Democrat Newspaper covers the 2001 Darby fire Damage

Rebuilt flume system gets back to work
by Sunny Lockwood

“Water is flowing through the ditches, canals, and rebuilt flumes on the Utica Power Authority’s system. Nine months and 14 days after the Darby Fire cut off UPA’s water system, the water was turned back on Wednesday. 

Rebuilding the historic three-quarter mile flume was complicated by the steep cliffside terrain and winter weather. Helicopters had to fly in portions of the iron trestle that held the wooden flume boxes. 

While crews labored from the fall to this month, a temporary overland pipe system powered by pumps kept about 10 cubic feet a second flowing to the city of Angels Camp, Murphys, and other nearby communities. 

When water began flowing Wednesday, UPA operators watched for leaks or other problems, but saw none, said Operator Dave Powell.

He said that the flow was increased to 30 cubic feet a second on Friday. “Angels Creek will have about two-and-a-half cubic feet a second in it and Murphys Creek will have 20 cubic feet a second,” he said. 

Water in the restarted system flowed at a rate of 20 cubic feet per second, and there is no longer any need for people to practice emergency conservation, said John Hubbell, UPA field administrator. 

“Everything’s fine, we’re back to normal,” he said. 

UPA’s two powerhouses – one in Murphys and one in Angels Camp – have been idle since the Darby Fire destroyed the flumes Sept. 5. “

What's Next ?

UWPA taking action to prevent a future disaster

After nine months, 14 days and just under $4 million later, the UPA flume system was back to normal operations. Unfortunately, almost 20 years later, we are still using the same extremely flammable material that we were using prior to the Darby Fire devastation. Due to U.S. Forest Service regulations in place to preserve the history of the flume system, UPA (now UWPA- Utica Water and Power Authority) is unable to rebuild the flume system with anything but, the original material, wood. We are currently taking steps to communicate these concerns to the U.S. Forest Service, in hopes that we can reach a mutual end goal that will be beneficial to UWPA, the U.S. Forest Service, and the communities we both serve.
Wood Flumes Replaced with Fire Resistant Material
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