Because Johns Hopkins is located in the Chesapeake Bay watershed, the University places an emphasis on mitigating storm water-related impacts. Some projects the University has completed include the addition of storm water bio swales, a rainwater capture system for reuse in cage washing in laboratories at the medical campus, new rain gardens, and an underground parking garage that replaced an impervious asphalt parking lot with one of the largest green roofs in the Mid-Atlantic.
In 2004, the Homewood campus completed an irrigation retrofit, complete with high tech monitoring systems, saving over 8 million gallons of water annually. Most campus landscaping and new design projects incorporate plants native to the Mid-Atlantic region that require little to no irrigation. New green roofs have also been installed on the Johns Hopkins Hospital and Cordish Lacrosse Facility.