Both water and energy are critical natural resources that are interrelated in both their production and delivery. In addition, water and energy are used in HVAC and industrial cooling processes. In many cases, energy can be conserved through the use of water, and water can be conserved if energy usage is allowed to increase. This paper proposes a simple way to compare the use of both resources through an index of the ratio of power saved divided by the water invested. This index could be utilized to set relative values on water and energy usage for codes or for guidance in "green" applications. The index could be determined for regional or even local climate conditions.