Evaluate the potential for nonpotable water sources, including rainwater reuse and graywater reuse. If non-potable water use seems feasible for your project evaluate the water demand for your landscape and the quantity of water reuse available to your project. Calculations, usually done by the landscape architect, have to account for annual rainfall on a monthly basis for the project location. Rainwater, which may need basic filtration but not usually additional treatment, can be piped directly to plantings to reduce the need for potable irrigation water. Evaluate the potential for graywater. Research graywater or rainwater regulations, and local incentives. Check with local authorities on acceptable rainwater and graywater capture, collection, and reuse methods. Local codes may place limits on some uses of alternative water supplies. Develop a water budget, both project-wide and for landscape irrigation.