New Bullards Bar Dam is a variable radius concrete arch dam in California on the North Yuba River. The dam forms the New Bullards Bar Reservoir, which can hold nearly 1,000,000 acre·ft (1.2 km3) of water. It is located near the town of Dobbins in Yuba County. The dam serves for irrigation, drinking water and hydroelectric power generation.
New Bullards Bar Dam was constructed by the Yuba County Water Agency. The agency was created through an act of the state legislature in 1959 specifically to construct a flood control reservoir in response to the flood of 1955. The bulk of the financing for the dam came from the issuance of revenue bonds. The dam was completed in 1969.
New Bullards Bar Reservoir provides flood control space between September 15 and May 31 of each year. There are 170,000 acre feet (210,000,000 m3) of flood control storage space between October 31 and March 31.The dam furnishes water to the New Colgate Powerhouse, which is located 5 miles (8.0 km) downstream. The added distance increases the head (i.e. elevation change). Its two Pelton wheels have a combined capacity of 315 megawatts and are some of the largest ever made. The small Fish Release powerhouse was constructed in 1986 at the base of the dam. It has a capacity of 150 kilowatts and generates power from water releases for fish on the Yuba River.
A 14-foot (4.3 m)-diameter penstock drains water from the New Bullards Bar Reservoir several miles through a mountain and down a large hill to deliver water to the Colgate Powerhouse. In 2006 a 168 inch (4.3 m) butterfly valve was designed and manufactured in Europe for installation in the penstock at the top of the hill to protect the powerhouse from flooding in the event that an earthquake or other event caused the penstock to rupture. This valve uses a design similar to that of the dam's base release works.
Capacity : 996,103 acre feet (1.228675 km3)