J. W. Wisda is a state-owned earth dam located in Topanga, California, with a primary purpose of recreation. Built in 1958, this dam stands at a height of 50 feet and has a hydraulic height of 43.3 feet. It holds a storage capacity of 45 acre-feet and covers a surface area of 4 acres, serving the surrounding area with a drainage area of 0.22 square miles along the Tr Topanga Can river or stream.

Managed by the California Department of Water Resources (DWR) under the Safety of Dams regulations, J. W. Wisda has a low hazard potential and is assessed to be in satisfactory condition as of September 2017. The dam is regularly inspected, with the last assessment conducted in September 2020. Despite its recreational focus, the dam's critical role in water resource management and climate resilience in the region cannot be understated.

Located in the Los Angeles County, J. W. Wisda contributes to the local water supply and environmental conservation efforts. As a vital infrastructure in the area, it ensures the safety and well-being of nearby residents while offering recreational opportunities. Its design and construction reflect a commitment to sustainable water resource management practices, making it an essential asset for water resource and climate enthusiasts in the region.