Water Research Yields Crucial Insights

By Paul Brown, Extension Specialist, Biometerology, Univeristy of Arizona
The University of Arizona has conducted a number of research studies during the past decade in an effort to better quantify the water requirements of desert Turfgrass systems. A number of conclusions may be drawn from these studies. First, they determined that water use averages between 4.9 and 5.0 acre-feet/acre per year. Second, the studies found that the golf industry’s current water allotment (in Tucson, for example, it’s 4.6) is adequate for year-round turf only if a series of conditions are met. The full allotment must be applied to the turf; the irrigation system must distribute the water uniformly; precipitation must be at or above normal levels; and the turf has to be growing in a soil with reasonable depth and waterholding capacity. These findings indicate that reducing turf area may not reduce total water use, due to “edge effects.”
As we move forward and begin the lengthy process of developing water duties and conservation plans for the Arizona Department of Water Resources’ (ADWR) Fourth Management Plan, which will be implemented in 2010, there are several issues we need to address.
Chief among these are salinity and drought, which are interrelated. Problems with salinity arise when an insufficient amount of water leaches through the root zone, preventing a buildup of salts. Drought can cause salinity problems, as can poor drainage or faulty irrigation systems.
Irrigation efficiency, therefore, will be of paramount importance to the future of water management in Arizona. So, too, will be the location and design of golf courses in the state.
The year 2010 may seem far away, but the process for developing the Plan will begin sometime in 2006. One of the main strengths of the Ground Water Management Act is that local Management Plans must be reviewed, adjusted, and reissued each decade, making sure that every region remains up to date.