Utah State University Extension
The American lawn is our nation’s single largest irrigated “crop” (Lindsey, 2005). In Utah, roughly 65% of our drinking water is applied to residential and commercial landscapes (Center for Water Efficient Landscaping, 2020). Landscapes are typically overwatered, which is why residential and commercial landscape watering is estimated to be one of the largest sources of potential water conservation in the urban setting (Endter-Wada et al., 2008). Plant materials also provide many environmental benefits, such as erosion control, water filtration, and temperature reduction. Knowing how much water to apply to the landscape can be a challenge and is one reason many Utah landscapes are over-irrigated. One source of information that water managers frequently use to minimize over-application of water and dial in the water needs of plants is evapotranspiration (ET). This fact sheet provides a basic understanding of ET, which is essential for homeowners to optimize plant water requirements and apply water conservation practices.
Schaible, Candace; Kopp, Kelly; and Muntz, Helen, "Watering the Landscape: Make It Easier With Evapotranspiration (ET)" (2020). All Current Publications. Paper 2151.