of several roads that ran through it, the diversion tunnel was closed and water began to rise behind New Don Pedro. The rising lake submerged Old Don Pedro Dam on April 12, 1970 and inundated the Gold Rush town of Jacksonville by June. The powerhouse and penstocks were completed by August 1970, after lengthy delays and setbacks due to the sheer scale of the generators, pipes and gates used in their construction. Some of the individual components were so heavy that a truck delivering one of the penstock sections sank up to its trailer bed in the road, and another was crushed when the driver braked, inadvertently snapping the chains that held the load in place. The total cost of the New Don Pedro Dam project, including site preparations, reservoir clearing and road relocations, was $115,679,000. The dam was formally dedicated on May 22, 1971 to a crowd of over 3,000 people. Among the dedication ceremonies were a speech by San Francisco mayor Joseph Alioto and a beef barbecue hosted by TID. Design and usage Rising above its foundations and above the Tuolumne River, New Don Pedro is a massive earth and rock fill structure containing of material. The long dam is wide at the crest and over wide at the base. High water releases are controlled by four sets of gates. A set of internal gates in the diversion tunnel can release up to , while a hollow jet valve at the base of the dam can discharge . The service spillway, controlled by three radial gates, has a capacity of , and finally the emergency spillway, a long concrete overflow structure, can discharge more than . The hydroelectric plant at the base of the dam has four generators capable of producing 203 MW combined. The TID's share is 139 MW or 68.47%, while MID receives 64 MW or 31.53%. Three generators, each with a capacity of 55 MW, were included in the original design of the dam while an additional 38 MW generator was incorporated in 1989. The plant generates an average of 618.4 million kilowatt hours (KWh) of electricity each year, equal to an average output of 70.6 MW. The cities of Modesto and Turlock receive a large share of their power supplies from New Don Pedro Dam. Don Pedro Reservoir has a capacity of , of which is reserved for flood control and is available for