 The dam was constructed in 1941 for the primary purpose of trapping sediment derived from anticipated hydraulic mining operations in the Yuba River watershed.Hydraulic mining in the Sierra Nevada was halted in 1884 but resumed on a limited basis until the 1930s during the great depression under the California Debris Commission.Although no hydraulic mining in the upper Yuba River watershed resumed after the construction of the dam, the historical mine sites continued to contribute sediment to the river.