The Annex Creek Powerplant holds two generating units manufactured by Allis-Chalmers. They are each driven by a horizontal axis, single jet impulse turbine. Each unit can generate about 1.6 megawatts at a generation voltage of 2,300 volts. The turbines (water wheels) may be original. One generator was rewound in 1967 and the other in 1977. The control and auxiliary equipment in the plant have been recently replaced.

Click here for an original engineering drawing of the turbine and valve

Click here to see a page from the Powerplant Operator's Log from 1916