How many gallons of water is needed to water a lawn that is 5000 sq ft


#1

I understand it depends on many parameters. But I thought I ask anyway.
We have a lawn that is around 5000 sq ft with st. augustine grass in Austin, TX.

What is typical watering schedule of this lawn will need in gallons per month?

I believe I am adding around 5000-6000 gallons per month in a summer month (June/July months).
What I am wondering is it too much, too less or what.

Thanks


#2

If you had zero precipitation during the month (just calculating the extreme case), and wanted to give your grass an inch of water a week, let’s round and say you give it 4 inches of water a month.
5000 sq ft * 1/3 ft = 1666.66 cuft = 12,468 gallons of water.

A quick search for average rainfall in Austin gives around 4 inches in June, and close to 2 inches for both July and August.
This would give you 0 additional watering required in June, and around 6,234 gallons during July and August.


#3

@Videoguy, a quick formula to ballpark the gallons of irrigation water needed per day (excluding rainfall) is:
((Eto x PF x SF x 0.62 ) / IE) – multiply this value by the number of days in the month.

ETo = Reference ET
PF = plant factor
SF = area to be irrigated in square feet
0.62 = constant value used for conversion.
IE = Irrigation efficiency.