Juneau's power supply has 19th-century roots

Some time ago, while wandering around in the underbrush about a mile or so from the Mendenhall Glacier, I came across an old road. It had not been used by motor vehicles in a long time but you could still make out the old ruts. The road ran parallel with the highway that goes out to the Mendenhall Glacier. I followed the road to within a short distance from the glacier where part of it turned up onto the highway. The main road continued on and looked to of been redeveloped into a trail. In following it I came across a jumble of concrete foundations and pieces of extremely large old metal pipe. I asked a few of my friends about the road and parts of an old building but none of them had any ideas. As time went on I kind of put it aside and forgot about it.


Sometime later, in another of my explorations, while hiking over the East Mendenhall Trail, I found an old trail that seemed to go up the Nugget Creek. I decided I had plenty of time so I began an interesting trek. I had noted, while on the East Mendenhall Trail, parts from an old railway, old wooden pipe, lots of cable plus a small dam on Nugget Creek. The Nugget Creek trail had some of this but also what looked like mining equipment. Having never heard of a mine in this area, I was intrigued. It seemed to me from the dimness of the path that few people had been up there in a long time. The trail dipped down close to the creek and it was tough going along a cliff that dropped directly into the creek. Finally, I broke out into a wide flat covered in head-high salmonberries, devil’s club, ferns and other low brush that almost obliterated the old trail. I continued on until I came in sight of the tiny Nugget Creek glacier. Realizing I had not planned to explore this trail and that it was becoming dark, I decided to return at a later date to continue my exploration.

The years went by and I never returned. However, I did learn of a tunnel that had been cut through the mountain to the Nugget Creek dam; the other end comes out halfway between the Nugget Creek falls and the U.S. Forest Service viewing center. The water that still comes out of the tunnel makes its own small falls and can be seen from several viewing places around the Mendenhall Glacier.

A few years ago I began to realize all of what I had accidentally tripped over was somehow connected and as a history buff I decided to find out more. As I have mentioned in previous writings, gold was found close to what is now Juneau by Joe Juneau and Richard Harris in 1880. Because most of the gold was below ground and had to be mined it didn’t take long for a need for something to power the mining equipment. Most of the early power projects were hydro mechanical. Large wheels were turned by water power, which in turn were connected by large belts to other machinery.

The Treadwell Group, directed by Frederick W. Bradley, developed the Treadwell Ditch Project in 1882. The Treadwell Ditch was a canal that skirted along the hillside from Cropley Lake at North Douglas toward the Treadwell area. Along its path it collected water by intercepting various streams. By the time it got to Treadwell it was 450 feet above the facilities, and the pressure it developed was used to drive various water wheels, including the 240 stamp mill. Later the water supplied steam plants. The Treadwell Ditch and 240 mill power plant were converted from hydro mechanical to hydroelectric by coupling the water wheel to an electric generator in 1898.

In 1893, Willis Thorpe, a local butcher, developed the first electrical generating project for the residents of Juneau, when he built a water wheel and generator on the banks of Gold Creek. He named his company Alaska Electric Light & Power (AEL&P). In 1896, Thorpe sold his company to John P. Corbus, Adam W. Corbus, John F. Malony, and Robert Duncan Jr.; all were affiliated with the Treadwell mines complex south of Douglas. Two days later The Searchlight reported that “the new Company will increase the capacity to 2,500 lights and extend service to Douglas.” It also mentioned that the manager of AEL&P, W.L. Grant, was taking a trip south “to secure new machinery for the steam plant which will be erected at the power house on Gold Creek.”

The Treadwell Cos., while continuing to look for opportunities to reduce their demand for oil-fired, steam-generated electricity, began construction of the Nugget Creek hydro plant in 1910. The Treadwell Cos. purchased the Ben Bullard gold claims on the east side of Mendenhall Valley and up Nugget Creek along with the water rights. They immediately began development of a transmission line from Treadwell to Nugget Creek. Power then could be sent from Treadwell to Nugget Creek to run the tools for construction. Once the project was completed the power could run the other way. By the end of 1911, a temporary 25-foot timber crib diversion dam and 300 feet of open flume were constructed to deliver water to a drain tunnel. This diverted most of the flow of Nugget Creek away from the construction site so a second tunnel could be built and the streambed excavated to allow placement of a concrete cutoff wall allowing the dam to be finished. A 650-foot tunnel had been driven from behind the dam, through the ridge from Nugget to Mendenhall Valley. The outflow of that tunnel became the small waterfall seen today. Work had also started in the fall of 1911 on the Nugget Creek Power plant.

A sawmill was developed to saw local timbers for the dam, pipe trestles and buildings. Other materials and equipment were ordered from down south. Most of these materials were landed at Fritz Cove and hauled over land by truck to the powerhouse.

In the spring of 1912, construction of the wood pipe began. The 4,562-foot-long pipe ran from the entrance of the tunnel in Nugget Creek’s lower basin through the tunnel. It then ran along the wall of Mendenhall Valley to a point near Steep Creek. It was constructed on only a slight grade supported for the most part by a trestle. The 48-inch diameter continuous stave pipe was made of 2-by-6 Douglas fir held together with iron bands placed every 3 1/2 inches. In total it contained 133,000 board feet of lumber and 120 tons of iron and steel. On the end of the wood pipe a 36-inch diameter riveted steel pipe ran down a steep drop to the powerhouse. Steel pipe was needed because of the extreme pressure the water was under by the time it got to the bottom of the drop. The powerhouse had a waterwheel and generator. The generator was built by General Electric and the waterwheel by Pelton Water Wheel Company. When operating in 1912, it generated 1 megawatt of electrical power at 2,300 volts. This was later stepped up to 22,000 volts and transmitted to Treadwell. By the end of 1913, the first power unit had generated electricity for an entire year. A second unit was installed, a 2 megawatt Westinghouse generator and was in operation.

By 1915 the dam had been completed. Treadwell mines were beginning to decline and management was reluctant to make additional heavy investment in Nugget Creek. The plant had some of its own problems. The small dam and reservoir meant the plant only generated at capacity during the summer months. The water, resulting largely from glacial run off, carried a heavy silt load causing two problems. The first was the small reservoir created by the temporary dam appeared to be filling in. Also, the fine silt carried through the pipe was causing a tremendous amount of wear on the water wheels and other parts, especially the needle valves used to regulate the speed of the wheels. These required frequent replacement.

By 1928 the Treadwell Companies and properties were sold to the A-J. By acquiring the Treadwell properties, the A-J gained control of several power plants including the Nugget Creek facility. Throughout the rest of the 1930s, the A-J continued to do well despite the poor economy elsewhere. In December 1943, the Nugget Creek Powerhouse was closed and boarded up. This was followed up on April of 1944 with the closing of the A-J gold mine.

In 1965 the Nugget Creek powerhouse and equipment were in total disrepair plus it had been severely vandalized. Because it was considered by the U.S. Forest Service a public nuisance and hazard to the increasing number of visitors to the area of Mendenhall Glacier, the remaining equipment was removed and the powerhouse torn down by A-J Industries. In 1973 AEL&P purchased the assets of A-J industries.

If you are willing to explore the area and get off the trails, you can still find all that I have found and see for yourself a part of the history of electrical power in Juneau.

• The following sources contributed to this article: “Hard Rock Gold,” by David and Brenda Stone; The Searchlight; Empire archives; “Southeast Sagas: A Tale of Two Tunnels” by Ann Chandonnet; “The Nugget Creek Powerplant and Power Development in Juneau” by David Stone and Scott Willis; “AEL&P: Century of Service 1893-1993”; State of Alaska Historical Library


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