SMUD uses mule train to move new hydro equipment

Sacramento Municipal Utility District (SMUD) engineers and contractors loaded a helicopter and 20 pack mules with three tons of construction equipment, tools and camping supplies for a journey through the Desolation Wilderness to replace a valve at Rubicon Dam and replace a weir at Buck Island Reservoir. The reservoirs are located in the remotest regions of SMUD’s 688-MW Upper American River Project hydroelectric system.

Since there are no roads to get there, transportation is limited to hikers and pack animals, which is challenging when the load includes a 2,300-pound valve, two generators that weigh almost that much, two sections of pipe weighing 900 pounds each and assorted heavy tools and equipment.

The valve on Rubicon Dam was replaced because a new operating license from the Federal Energy Regulatory Commission requires SMUD to release higher water volumes than the old valve could handle. The weir at Buck Island measures and verifies the flow rate of water released from the reservoir and was about 50 years old. Two separate groups of employees and contractors worked 12-hour days for the 10-day construction project.

The U.S. Forest Service limits mechanized equipment in the wilderness to the extent possible to maintain its tranquility. The Forest Service allows SMUD a minimal number of helicopter flights across the wilderness boundary for regular maintenance activities at the facility. Sometimes additional flights are needed for special projects. For the valve-replacement project, SMUD and the Forest Service agreed to allow hauling of some heavy or awkward items by helicopter while transporting the bulk of food and equipment using a team of 20 pack mules and four mule handlers.

The mules are owned and handled by a contractor. Their journey began at a base camp at the Loon Lake equestrian campground. From there, the mule team traveled unloaded for the first five miles on the Rubicon Trail. SMUD transported all the equipment and supplies by helicopter from Loon Lake to the border of Desolation Wilderness. At the border, the mules were loaded up for the final 1.6 miles to Rubicon Dam. A team of five mules and one or two handlers made supply runs to the Rubicon camp to deliver ice and food and to haul away trash.

As the projects were so remote and without quick access to emergency medical services, SMUD provided CPR and first-aid training, and both groups were equipped with well-stocked first-aid and trauma kits, including oxygen tanks. Because there is no cell phone reception in the backcountry, the groups kept in touch with two-way radios and satellite phones.

Following installation of the new valve, the mules hauled back all the equipment and waste to the wilderness border. SMUD left the area the way it was found, respecting the leave-no-trace philosophy that is typical of all SMUD projects.