To supply the powerhouse, Halsey Forebay was built to the north (intersection of Christian Valley Road and Bancroft Road ). The site was the old Columbia ranch dating from 1858 owned by the Bancroft family. Since the Bancrofts would not sell, the PG&E took the ranch by right of eminent domain, re-locating the family and set up offices in the old home. James Martin, Manager of Drum Division in Colfax, was in charge of construction of the forebay and powerhouse. Two earth dams were built to hold 300 acre feet of water from the Bear River Canal. The water exits over the hill by syphon in the penstock to the powerhouse. In December, 1915, an air compressor plant was installed between tunnels 5 and 6 to furnish air for the drills. This was the only power used in the whole project. At this time, the electric power lines were built to this point from Drum.
Halsey powerhouse had an afterbay (Christian Valley Road and Dry Creek Road) to catch the water and direct it into the Wise Canal to Rock Creek Dam. Excess water flowed down Dry Creek. Rock Creek Dam was built in 1916 for storage. It was concrete, 1015 feet long, 36 feet high, consisting of 35 arches of 30 feet each with a spillway in the center. Net storage was 440 acre feet. The multiple arch construction was the longest of its kind built at that time and was of European design. Several engineers on the project were from Europe.
Wise powerhouse is similar to Halsey. The water came from Rock Creek via the Wise Canal to the forebay located at Merry Knoll (off Mt. Vernon Road west of Nevada Street, Auburn). The penstock consisted of 1600 feet of 96" diameter wood stave pipe, 500 feet of reinforced concrete lined tunnel 8' in diameter and 6700 feet of steel pipe. The water enters through the penstocks over Duncan Hill (accessed by Stone House road, off of Ophir Road) to the powerhouse at the corner of Wise and Ophir Roads. The horizontal, Francis type turbine had 20,000 HP and single discharge design. It was the largest single wheel built at that time by Pelton Water Wheel Works in San Francisco. The turbine was on display in the Machinery Hall at the Panama-Pacific International Exposition in 1915 prior to installation. The 12,500 KVA electric generator was one of four original units for the Drum Division. Static head of water available was 520 feet. Canals diverted the water at the tailrace to the large agriculture industry in the Loomis Basin. The electricity went to Standard Electra lines at Stockton then to Cordelia.
This powerhouse was named for James H. Wise, Civil and Hydraulic Engineer. Wise was born February 17, 1880 in Denver, Colorado. He became interested in mining because his father was a miner in Colorado and New Mexico. At 12, Wise came to Alameda to complete grammar school then entered Lick School in San Francisco, graduating at 19. A crackerjack in math, he went to the University of California at Berkeley specializing in mining, graduating in 1903 with a Bachelor of Science degree. He was invited back to Lick to teach for a year. He then joined PG&E as an instrument man, then surveyor, then became assistant to Frank Baun, Consulting Engineer. When Baum resigned, Wise was made hydraulic and civil engineer. After six years, he left PG&E to become partner with Baum in private business. While away, he spent two months in Dawson, Yukon Territory assisting in the construction of a 7,000 kilowatt hydro-electric installation. He also worked on the North Fork of the Klondike for Canadian Klondike Company, Yukon gold company, and Granville Mining Company. Other power projects with Baun included the transmission and street car systems at Monterey. In 1911, Wise rejoined P. G. & E as Assistant General Manager. He was killed in an auto accident in San Francisco while on Company business on September 16, 1912 at the age of 32. He was so well thought of that PG&E started the Wise Library in his memory with his engineering books.