You won’t find it in the credit requirements, but the best strategy here is to limit the amount of hardscape and number of parking spaces provided in the first place. This not only reduces the hardscape square footage you must treat with light-colored paving, shading, open-grid paving, or covering, it can also help you earn several other credits.
The majority of projects choose to pursue this credit through the fourth option: locating at least 50% of parking spaces under cover. Most often, this means underground parking or a parking garage.
Screenshots and Guidance: LEED Online WEp1 Form Read More
Following on this page are screen captures that show how to document WEp1: Water Use Reduction for LEED-NC 2009. Some comments and explanations are interspersed. The following is displayed with permission of the USGBC.