Projected Utility Rate Impacts Associated with Fish Passage Investments on the Tuolumne River

The costs of constructing and operating fish passage projects around hydro-electric dams can amount to hundreds of millions of dollars, and yet such projects may be affordable under longterm financing and distribution of costs to electric and water ratepayers. We evaluate the potential distribution of the cost of providing fish passage around the La Grange and Don Pedro Hydroelectric Projects on the Tuolumne River to Turlock Irrigation District (TID) and Modesto Irrigation District (MID) electric and water ratepayers. Estimates of the project capital and operations and maintenance costs are converted to annualized costs and allocated among various entities. For TID and MID these costs are then allocated among customer classes in proportion to annual operating revenues and presented as estimated annual utility rate increases required to finance the proposed fish passage project. We find that a fish passage project with an estimated capital cost of $170 million would result in rate increases of 3.7 percent for TID customers and 1.3 percent for MID customers. We also present estimated rate increases for a range of projected costs and for alternative cost sharing scenarios that may include other entities, such as the City and County of San Francisco.