Provide adequate grades for surface lots to minimize the possibility of low or flat spots. Accumulation of standing water in a lot is a hazard for both vehicle and pedestrian movements, particularly in cold climates where freezing may lead to icy spots. UFC 3-201-01 provides basic principles for grading and draining parking lots. Provide positive drainage in parking lots and adhere to the requirements given. As a rule of thumb, typically minimum grades of 1 percent for asphalt surfaces and 0.5 percent for concrete surfaces are recommended.