Haynes Reservoir, also known as Lake Margaret, is a privately owned dam located in Big Bend, California. Completed in 1965, this earth dam stands at a height of 67 feet and has a storage capacity of 5870 acre-feet, serving primarily for flood risk reduction. Situated on Goose Creek with a drainage area of 5.3 square miles, the reservoir covers a surface area of 241 acres and plays a vital role in irrigation and water supply in the region.

With its high hazard potential and satisfactory condition assessment, Haynes Reservoir is regulated by the California Department of Water Resources for safety and compliance. The dam, with a hydraulic height of 62.5 feet, is designed to withstand potential risks and is subject to regular inspections to ensure its structural integrity. The surrounding area, under the jurisdiction of the state, benefits from this reservoir's flood protection measures and water resource management.

Managed by private owners, Haynes Reservoir contributes significantly to the local community by mitigating flood risks and providing essential water resources. The dam's strategic location on Goose Creek, overseen by state regulatory agencies, highlights its importance in safeguarding the region against potential water-related hazards while supporting agricultural and urban water needs. Enthusiasts of water resources and climate will appreciate the role of Haynes Reservoir in balancing flood control, irrigation, and water supply in Shasta County, California.