Many factors will affect the size you choose for your water meter. Sometimes during the quoting or planning stage, we have to decide on the water meter size before we know all of the details about available pressures and flows available onsite. These are our considerations when choosing a meter size:
Water Window
How many hours per day are you willing to water? We try to ensure that each of the irrigation systems we design can effectively deliver 35mm of water across the irrigated area over 7 days, watering a maximum of 8 hours per day(or night). This is a little bit overkill, but ensures that we have enough water during the plant and turf establishment period.
General Calculations and allowances
We can often assume that we will achieve the following flows to feed spray irrigation systems through water meters
At these flows, we assume we can achieve the required working pressure for spray irrigation
- 20mm water meter we can achieve 20LPM
- 25mm water meter we can achieve 55LPM
- 32mm water meter we can achieve 75LPM
- 40mm water meter we can achieve 100LPM
*Pressures and flows vary greatly from site to site, These are general calculations we use for estimating purposes, sometimes pressure boosting is required and on occasion we can achieve more flow through a meter than assumed above
Water meter sizing compared to irrigated area
When estimating, we assume that the following size water meters will be adequate for the
- 20mm < 2194m2 irrigated area
- 25mm <5280m2 irrigated area
- 32mm <7200m2 irrigated area
- 40mm <9920m2 irrigated area
Just a reminder that these calculations are general and are useful for preliminary planning and estimation purposes. A specific site evaluation should always be carried out to determine the actual water meter size requirement.
If you need help with sizing your water meter, give us a call!
