Preserving the health of natural water features such as lakes, rivers and wetlands is an important part of building green. The surfaces of the buildings and infrastructure we construct, and the way water is consumed within these buildings, are the key considerations in designing structures that will preserve our water resources. Green building practices targeted towards improved water management generally fall under the following categories:

Stormwater Management
Managing stormwater runoff helps to mitigate the impacts of urbanization on natural water features by improving the quality and reducing the quantity of storm flows.  In recent years stormwater management has begun to focus more on preserving and/or mimicking the natural hydrologic balance by choosing practices that promote increased infiltration and evaporation and lower surface runoff volumes and flow rates.  The LEED Green Building Rating System grants points for permanent stormwater management measures for the development, and also for temporary management of stormwater during construction - referred to as Erosion and Sedimentation Control. 

Water Conservation
The common element of the water efficiency component of green buiding is the reduction of potable (municipal) water use for both the indoor and outdoor spaces.  This may be accomplished with a variety of technologies and strategies, including rainwater harvesting systems, landscaping with water-wise plants, and water efficient appliances, fixtures and irrigation systems. 

Wastewater Reduction
Reducing the amount of wastewater a development contributes to the municipal sewage system is another important element of sustainable water management.  Installing low-flow or waterless plumbing fixtures not only helps to conserve water, but also means less wastewater discharged to the city's sanitary sewers.  Some developments have also taken this a step further by installing systems to treat all their wastewater on-site.