Water Supply Reliability

Return flow ratio measures the percent of available water previously used and discharged upstream as wastewater. This indicator was used by the World Resources Institute in the Aqueduct 2.0 project.

The maximum storm intensity that can occur without causing more than some amount (e.g., $10 million) in damages due to water infrastructure disruptions, including levees and floods

Annual withdrawal of ground and surface water as a percent of total annually renewable volume of freshwater.

Upstream protected land measures the percentage of total water supply that originates from protected ecosystems. Modified land use can affect the health of freshwater ecosystems and have severe downstream impacts on both water quality and quantity. The World Resources Institute used this indicator in the Aqueduct 2.0 project.

Upstream storage measures the water storage capacity available upstream of a location relative to the total water supply at that location. The World Resources Institute used this indicator in the Aqueduct 2.0 project.

Total agricultural, residential, and commercial water demand, i.e. demand for all uses other than environmental needs and basic human drinking water requirements.

The water footprint is the sum of the water used directly or indirectly to produce goods and services consumed by humanity. Agricultural production accounts for most of global water use, but drinking, manufacturing, cooking, recreation, washing, cleaning, landscaping, cooling, and processing all contribute to water use.

Volume of water re-used (same volume can count more than once) as a fraction of total water used, including onsite, or recycled.

Water Risk refers to the risk to water supplies from changes in climate and water withdrawals. The World Resources Institute used this indicator in the Aqueduct 2.0 project.

Water scarcity is a function of water availability and water use. This index is used by the global Environmental Protection Index and represents the over-use of water in a region.