Welcome to the Washoe Evapotranspiration Website!

Your actual watering needs may vary according to water pressure, applied gallons per minute, nozzle size, coverage, soil type and slope of the land.

When setting your timer at the suggested "run-time," use short but frequent watering cycles for best results. For example, if your sprinkler type indicates watering for 20 minutes, split-up the run-time into two to four increments, ie., two at 10 minutes or four at five minutes if possible, allowing at least one hour between watering. This allows the water to soak deep into the soil and prevents run-off.

Calculate your runtime

inches per day
Runtime result minutes per day

How is this calculated?

When do I water?


No Watering

Tuesday, Thursday, and Saturday

Even Residential Addresses

Wednesday, Friday, and Sunday

Odd Residential Addresses

The Washoe E.T. project is a network of weather stations located in the region surrounding Reno, NV that monitor evapotranspiration rates. These rates can then be used as a tool to estimate lawn and crop watering needs.

To see a map of the weather station sites, click here

For gross estimated runtimes for small to medium
turf areas, click here

For more information about the Washoe E.T. project or to print out our brochure, click here