Existing Problem: Low Pressure Sprinklers on Top of Boom
The operating pressure is in the medium range (20-50 psi). Typically the system will have an end gun.

Water Conserving Practice: Place Low Pressure Sprinklers on Drops

Drops are inverted J-shaped tubing extending from the top of the pivot boom to the sprinklers below the pivot boom (near the crop canopy). They reduce wind effects and evaporation losses by placing the spray in or just above the mature canopy. This sprinkler package should include new sprinkler spacing and operation at a lower pressure (15-20 psi). Well-designed fixed or rotating sprayers on the drops will also have larger droplet sizes. Caution is needed to prevent runoff water losses (see below).

¹Potential No. of Irrigation Systems Affected	2550
Estimated Water Savings (%)	5 (0 to 10)
²Average Year Water Savings (million gal.)	2423
³Dry Year Water Savings (million gal.)	4154
Est. Cost of Full Implementation on Avg. System ($, 1998)	$1,500
Statewide Costs for Full Implementation ($, 1998)	$3,830,000
Cost / Unit of Water Saved in Average Year ($, 1998 / million gal.)	$1578

Estimated water savings are between 0 and 10 percent. No water savings would be expected from systems which are already operating only at night and using good practices. The high end is associated with systems which operate continuously through 24 hours in very open areas. The average estimated water savings is about 5%.

Of the 8,000+ center pivot systems currently in the state of Georgia, 2,550 are estimated to be candidates for this type improvement. The potential water savings from this practice alone would be about 2,423 million gallons during an average year. The cost to implement such a change is about $1,500 per system. The estimated statewide costs for full implementation is $3.83 million. The cost per unit water saved is estimated to be about $1,578 per million gallons of water saved.

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.