The resources link for this credit directs us to use the ETo software calculator from the FAO website:
http://www.fao.org/nr/water/eto.html
Previously I have used the WaterSense website to get ETo data, but after pressing the "go" button, the data does not pop up anymore:
http://www3.epa.gov/watersense/new_homes/wb_data_finder.html
In lieu of the software, would it be acceptable to use this source to gain ETo data? After entering the latitude and longitude of your site, the ETo is provided with fewer steps than the software. It looks like it uses the Penman-Monteith equation like the above software does, but without the ample technical jargon.
http://wcatlas.iwmi.org/Default.asp
Are there any concerns with using the IWMI to get ETo data to satisfy this credit?
Edward Malesevich
Sustainability AdvisorTranswestern Sustainability Services
13 thumbs up
March 8, 2016 - 9:29 am
Hi Stephanie,
We have started to utilize the IWMI Online Climate Summary website for several pieces of climate information, one being ETo. I definitely agree with your statement about this website being much simpler to use than other sites, and their methodology is solid. You should be fine using the IWMI site for your ETo data.
Priscilla Joseph
3 thumbs up
March 23, 2022 - 10:27 am
The IWMI website no longer has the IWMI Online Climate Summary Service Portal with the ETo values, what is the new source you are using?
Trista Brown
Project DirectorWSP USA
449 thumbs up
March 24, 2022 - 1:55 pm
Hi Priscilla - this website works for me: https://www.epa.gov/watersense/water-budget-data-finder
Priscilla Joseph
3 thumbs up
March 24, 2022 - 5:27 pm
Hi Trista,
I'm looking for evapotranspirstion rates outside the US, my projects are based in the Middle East
Trista Brown
Project DirectorWSP USA
449 thumbs up
March 29, 2022 - 4:50 pm
Hi Priscilla - thanks for clarifying. Have you checked whether there are any USGBC Chapters in the countries where you're working? They might be a good source of information. Unfortunately I don't have any ETo sources for the Middle East.
Devendra Chaughule
Senior Manager - Sustainable ServicesSurmount
29 thumbs up
May 11, 2022 - 12:10 pm
Hi Trista,
Did you get any ETo source outside US? I am also looking similar data for India.
Trista Brown
Project DirectorWSP USA
449 thumbs up
May 11, 2022 - 12:50 pm
Hi Devendra - I recommend reaching out to USGBC Chapters in India, or the India Green Building Council, to see if they can support. Unfortunately I don't have ETo data for India.
Michelle Robinson Schwarting
140 thumbs up
November 14, 2023 - 2:46 pm
Try this link for ETo data worldwide:
https://aquastat.fao.org/climate-information-tool/
(There's a map you can click on to get the data about your selected location. Or you can enter your Lat./Long.)