A big box parking lot requires 150% more surface area than the store itself. The planning goal is to reduce the deleterious effects of urban stormwater runoff from hard surfaces using Low Impact Development (LID) technologies. To promote decentralized water infiltration, pervious surfaces are substituted for impervious hard surfaces. This facilitates treatment of polluted water while reducing the heat island effect. Second, to decentralize and dampen runoff flow, a velocity treatment train with vegetated rain gardens, bioswales, infiltration trenches, and tree box filters organize the lot. This allows for a size reduction of an unsightly detention basin, whose only ecological service is storage.