Mary Street is a vital flood risk reduction structure located in Casa Blanca, California, along the Alessandro Wash. Owned by the local government, this earth dam stands at a height of 40 feet and was completed in 1981. With a storage capacity of 320 acre-feet and a drainage area of 6.7 square miles, Mary Street plays a crucial role in mitigating potential flooding events in the region.

Regulated by the California Department of Water Resources for dam safety, Mary Street has a high hazard potential but is currently assessed to be in satisfactory condition. Regular inspections ensure its structural integrity, with the last assessment conducted in September 2017. In the event of an emergency, the dam has emergency action plans in place, although the details of their preparation and adherence to guidelines are not specified in the data. Overall, Mary Street serves as a key infrastructure for water resource management and climate resilience in Riverside County.

Represented in Congress by Mark Takano, Mary Street is part of the flood risk reduction infrastructure under the jurisdiction of the Los Angeles District of the US Army Corps of Engineers. Its location at the confluence of multiple waterways highlights its strategic importance in protecting surrounding communities from potential inundation. As climate change continues to impact precipitation patterns and increase the frequency of extreme weather events, the maintenance and proper management of structures like Mary Street are essential for safeguarding lives and property in the region.