Existing Problem: No Uniformity Test, Calibration, or Major Maintenance Check in Past 5 Years.
Just as a truck or tractor must be tuned up periodically to continue operating efficiently, irrigation systems must be checked to see if they are operating according to design. This proposed practice does not directly save or waste water in itself. However, modifications to the system that improve uniformity, correct operating pressures, or repair leaks can save water.

Water Conserving Practice: Performance of an Irrigation Audit.

Checking pressure anf flow rate The irrigation audit is a full analysis of the entire irrigation system. An audit is essential to determine the most effective and needed recommendations for reducing water use. Flow and pressure, as well as fuel or power consumption are usually a part of the irrigation system audit. Flow meters, now installed by the Georgia Soil and Water Conservation Commission, and good pressure gauges can help you determine if your system is operating according manufacturers specifications.

Buckets set for uniformity check An important part of any irrigation audit is a uniformity check. While often performed by professionals who can compute uniformity indices and avoid biases by sprinkler position, you can check variation in your field at any time. Set buckets randomly or in a line, but be sure all parts of the system are included. If uniformity is poor, check for broken and leaky sprinklers. If those are fixed, it's time to contact your dealer to have a new sprinkler package designed for you. Check with NRCS and your Soil and Water Conservation District to see if there are any opportunities for sprinkler-refit cost sharing in your area.

¹Potential No. of Irrigation Systems Affected	11,700
Estimated Water Savings (%)	?⁵ (?⁵)
²Average Year Water Savings (million gal.)	0
³Dry Year Water Savings (million gal.)	0
Est. Cost of Full Implementation on Avg. System ($, 1998)	$1,000
Statewide Costs for Full Implementation ($, 1998)	$11,700,000
Cost / Unit of Water Saved in Average Year ($, 1998 / million gal.)	0

Estimated water savings are between -15 and +50 percent if improvements are made. Additional water may be required if uniformity is affected by clogged emitters in a drip system or operating pressures have not been sufficient (too many zones in a drip system operated at one time). Water savings may be associated with worn sprinklers with larger orifices than in the original new sprinkler, fixing major leaks, better zone management in a drip system, or end-gun shutoffs and sprinkler package changes in sprinkler systems. On the average, the estimated water savings are about 5%, but water and energy will be used more efficiently.

An estimated 11,700 systems are considered to be at least 5 years old and have not had a complete irrigation audit in the last 5 years. The average cost for an irrigation audit on a 100 ac system is about $1,000. The statewide cost for full implementation is estimated at $11.7 million. Obviously, the changes required to improve irrigation systems would have additional costs, but this audit provides essential information to determine what, if anything, needs to be changed.

Although audits themselves do not achieve water savings, the benefits of more efficient water application can be directly tied to improved and/or more consistent crop yields when corrections are applied.

The implementation of a program to encourage irrigation audits across all systems in Georgia where necessary would provide additional information on the efficiency of current irrigation practices and systems. Understanding how much water can potentially be saved is essential to future recommendations on agricultural water use and design of water conservation implementation programs.

Source: Evans, R.O., K.A. Harrison, J.E. Hook, C.V. Privette, W.I. Segars, W.B. Smith, D.L. Thomas, and A.W. Tyson. 1998. Irrigation conservation practices appropriate for the Southeastern United States. D.L. Thomas (ed.) Geologic Survey Project Report No. 32. Georgia Geologic Survey, Georgia Department Of Natural Resources, Environmental Protection Division, Atlanta, GA 30334. 43p.