||Rainwater harvesting has provided a water source for communities around the world
dating back to circa 1500 B.C. This ancient technology continues to serve populations
today, mainly in poor, rural or dry regions of the world and island communities.
Contemporary green building and stormwater management programs (e.g., Leadership in
Energy and Environmental Design – LEED, Low Impact Development – LID, Better Site
Design) suggest that rainwater harvesting can serve as a valuable stormwater management
tool even in areas where municipal water supplies are readily available. Regardless,
private developers are most apt to incorporate these systems into commercial development
designs if the benefits justify the costs.
Analyses of local rainfall data and predicted potential water usage at commercial
facilities in Arlington County, Virginia reveal that rainwater harvesting systems
conserve potable water, protect surface water quality and minimize flood risk. However,
economic analyses from the perspective of a private developer using two case studies
of commercial developments in Arlington suggest that the benefits of incorporating
rainwater harvesting into building designs do not justify the cost of implementing
this technique. Notwithstanding, results from a sensitivity analysis indicate that
charging tenants a modest price premium of one percent or less for the privilege of
occupying a “green” building yields a positive return to investing in rainwater harvesting.