IRRIGATION AND WATER MANAGEMENT
Flagging heads makes it much easier to place catch cans. Photo by Brad R. Jakubowski
LIKELY RESULTS OF AN AUDIT To gain perspective on how much land is occupied by turf in a typical sports field, the square footage must be calculated. Assuming a football field, with the dimensions of 360 feet by 160 feet, the minimum square footage is 57,600 square feet. Of course, many fields are larger than this, as they include some track and field accommodations, but for consistency, 57,600 will be used. Considering that 1 acre of turf = 43,560 square feet; thus 57,560 ft ² / 43,560 ft ² = 1.32 acres.
The next important formula is for acre-inch, which is the amount water required to cover an acre of land one inch deep in water, which is 27,154 gallons.
Next, it’ s important to calculate how much water is required to apply one inch of water to a minimal area football field: 1.32 acres of land. The calculation is 1.32 acres x 27,154 gallons = 35,843 gallons of water.
The natural follow up question is,“ How much water would be required to irrigate this field during one week?” If one inch per week is required, then the answer is the same, 35,843 gallons. If rainfall is received, that amount should be subtracted from the required amount; if windy or high evapotranspiration conditions prevail, then additional water is required and should be added to the total.
Record pressure measurements. Photo by Brad R. Jakubowski
Here’ s where the calculations come alive: 35,843 gallons are required in a given week, and the system is running at 50 % efficiency as documented by an irrigation audit, the total applied would have to be double what is desired because the driest areas are receiving half of what the adequately watered areas are receiving. Hence, 2 inches of water or 71,686 gallons would need to be applied for the week. This would obviously result in many areas being grossly overwatered.
26 SportsField Management | September 2025 sportsfieldmanagementonline. com