The landscape architect develops a baseline outdoor-water-use calculation based on mid-summer (July) and compares that to a calculation for the planned project design case water use (also for July). The difference is the percent reduction and identifies credit achievement. Factors included in the calculations are: plant species, density, microclimate, evapotranspiration rate, irrigation efficiency,, and non-potable water use, and controller efficiency (gains from controller efficiency cannot exceed 30% in July). The local project baseline case is a subjective calculation that will vary by city and is based on standard practice in that region. The landscape design case is created by setting the irrigation variables to values representative of the actual designed landscape plan. The landscape water efficiency boundary used must be the same project boundary used for all other LEED credits. (See the documentation toolkit for more information.)
