California Department of Parks and Recreation (DPR) is proposing to install sediment discharge control measures at Malakoff Diggins State Historic Park (MDSHP). MDSHP is located in Nevada County approximately 9 miles northeast of Nevada City, and includes the historic town of North Bloomfield, a public campground, a pond (Blair Lake), wooded areas with hiking trails, and the former hydraulic mine in the Malakoff Diggins basin.
Stormwater discharged from the Malakoff Diggins basin carries sediment and other pollutants that adversely affect downstream water quality. DPR has developed a Pit Drainage Runoff Sediment Control Best Management Practices Plan (BMP Plan) identifying BMP components that would be installed and maintained in the basin to reduce sediment discharge. The BMP components include a rock grade control structure and brush barriers to capture coarse sediment in the eastern portion of the basin, a swale to divert stormwater runoff for longer retention within the basin, and a soldier pile wall to slow stormwater discharge from the basin and increase retention within the basin. In combination, these BMP components would reduce sediment discharge from the basin thereby improving water quality in downstream waters including Humbug Creek and the South Yuba River. DPR anticipates construction of the BMP components in the summer of 2023.
In compliance with the California Environmental Quality Act (CEQA) and State CEQA Guidelines, DPR has prepared an Initial Study evaluating the environmental effects of the BMP Plan. As designed and with implementation of requirements and mitigation measures identified in the Initial Study, DPR has concluded that the project would not result in any significant adverse environmental impacts and would improve downstream water quality.
DPR issued a draft Initial Study/Mitigated Negative Declaration (IS/MND) on November 18, 2022, initially for a 30-day review and comment period. DPR has extended the review and comment period for an additional 30 days. The draft IS/MND is available for public review and comment through January 18, 2023, and can be viewed and downloaded from DPR’s Internet Website at: https://www.parks.ca.gov/?page_id=981