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.

    

     
    The 85% efficiency is the result from using a crop coefficient in the equation. The crop coefficients are used with Evapo-transpiration to estimate specific crop evapotranspiration rates. The crop coefficient is multiplied by the Evapotranspiration value to arrive at a crop ET (ETc) estimate. The resulting ETc can be used to help schedule when an irrigation should occur and how much water should be put back into the soil.

    

     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 5 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

    

    
  psi

    
 gpm

    
 feet

    
 feet

    
 inches per day

    
 percent

    
 

    
Runtime result minutes per day

    

      
 

         How is this calculated?  

    

     
  

  
  
  

    
What are my watering days?

    Monday:
    
    No watering, gives our water system a chance to recharge

    
 
    Tuesday, Thursday and Saturday
    
    Even Addresses

    
 
    Wednesday, Friday and Sunday
    
    Odd Addresses

    

    
Shut down your sprinklers between 12 p.m. and 6 p.m.

    
Memorial Day through Labor Day

    

    

    

    
What is Washoe EvapoTranspiration and how does it pertain to me and my yard? 

    
The Washoe E.T. website has been developed to help you water less and still have an attractive lawn. This site will show you how to use just the right amount of water to replace moisture that has been lost from the soil and grass.

    

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

    

     The EvapoTranspiration, or E.T. for short, is a method of lawn watering that help Nevadans save our most precious resource - water.  E.T. also helps improve water quality.  By watering less, you avoid runoff.  Overwatering causes more water to run off than soak in.  This runoff could carry pollutants from the gutter into our water supply. 
 

    
The less waste we create, the better.

       

       

      Some extra useful information: 
      

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

    

    Information regarding applying proper watering and lawn care - click here 
  
   

   

    Gross estimated runtimes for small to medium turf  - click here
    

    

    Printable  Washoe E.T.  brochure, click here
     (spread the word)
    

    
  
    TMWA holds free irrigation workshops each year to assist customers with system start up, setting controllers for Weather - Wise Watering. Please email  conservation@tmwa.com to RSVP for an upcoming workshop, or for more information about watering- click here.