Hello,
I’m running 4 zones comprising 3 lawn using Hunter MP rotators and 1 drip flowerbed using point emitters. I’ve been able to determine my actual water usage based on the manufacturers specs of the rotators and emitters, and confirmed they were close based on readings from my actual household water meter, but the Rachio is reporting my water usage at almost twice what the actual usage is.
For example, yesterday my systems actual usage was 1,584.12 litres but Rachio is reporting my usage as 3,143.14 litres.
Is there a way to tweak the settings for each zone to make Rachio usage data more accurate?
I took a peek around this forum and didn’t find anything concrete on how to fix this. There was this link How we calculate water usage provided in a couple posts I found that I though might be helpful, but that page is no longer available.
Usage in Rachio is a calculated figure based on nozzle PR and area. IMHO, this calculation is fairly easy to figure out for grass zones since you can physically measure the grass area, but drip zones are much harder to calculate since you are talking about a specific small emitter area only…
Use this formula
Nozzle in/hr = (Gallons / mins running / Area in sq. Ft) x 60
Nozzle cm/hr = ((Litres / mins running / Area in m2) X 60)/10
This will give you the figure which will then ensure that the grass is watered correctly too - since it will currently think that you have given the grass twice as much water than you actually have
Precipitation rate (imperial units) is calculated:
Precipitation rate (in/hr) = 96.25 x flow (gpm) / area (sq ft) †
and the metric equivalent is:
Precipitation rate (cm/hr) = 100 x flow (cu m/hr) / area (sq m)
† This assumes perfect (100%) efficiency - uniformity of application by good coverage of similar nozzles and proper sprinkler placement. Since efficiency is a station setting that’s commonly NOT 100%, but easily adjusted, it may be better to exclude it from the precipitation rate, which you or Rachio might be using to calculate things like usage.
