Golf is considered vitally important to Tucson's tourist economy. There are 38 golf courses in the Tucson Active Management Area, established to keep track of groundwater use in the greater metropolitan region. Golf courses use 3.3 percent of the groundwater.
Most golf courses have more than 80 acres of "water-intensive landscape," according to the Arizona Department of Water Resources (ADWR). This acreage makes golf courses by far the largest water consumer of what are called turf facilities--parks, schools and cemeteries are among them--using 80 percent of all turf facility water.
"The water requirement for an acre of turf grass ... is just shy of 5 acre-feet per acre, per year," said Paul Brown, extension specialist in biometeorology at the University of Arizona. That "is what evaporates off a green turf surface year-round."
The problem is that golf courses in the Tucson Active Management Area are targeted to use only 4.6 acre-feet of water per acre, per year. Each acre-foot signifies the amount of water that would cover an acre of land at the depth of one foot. This works out to 325,851 gallons of water per acre-foot. Back in 1995, golf resorts were using 4.7 acre-feet of water to keep their greens green. This 0.1 acre-foot, though seemingly small, adds up to millions of additional gallons of water per golf course.
Targets for water usage were set so the amount of groundwater pumped from the underlying aquifer doesn't exceed the amount naturally or artificially recharged. This, in turn, would help ensure ample water supplies and prevent the ground from sinking underneath Tucson, causing structural damage.
Also contributing to water use is a technique called over-seeding. Bermuda grass is fine in the summer. It is "a heat-tolerant grass, a relatively low-water-use grass for this area," said Brown. "But in the winter, because of cold temperatures, Bermuda grass will go dormant and turn brown."
Golf courses must then put in a cool season grass, such as winter rye, over the Bermuda grass, to keep the turf green throughout the winter. Then in April, when the weather heats up, the Bermuda grass "will come back and take over the tufted areas again."
But if you subtract how much water the turf needs versus how much it is allocated, "something doesn't match," said Brown. "The reality is that you have to look at rainfall."
Tucson gets about a foot of precipitation a year. But "a lot of that falls at inopportune times for effective use by any vegetation because it comes quickly at times and runs off. Or you get heavy rains that will move through the root zone before the plants can extract some of the water," Brown said.
And, this latest winter storm aside, not much precipitation has fallen of late in Tucson, making 2001 the 12th driest year on record, according to the National Weather Service.
There are then only two ways for golf resorts to keep the winter rye grass alive and meet their water restrictions. One is by not over-seeding their entire tufted area. The other is to use effluent water.
TREATED EFFLUENT IS water collected from homes and businesses by the central sewage system that is then treated at wastewater treatment plants. Since effluent water is treated water that has been used, the amount of effluent increases as the population increases. There was 70,100 acre-feet of effluent water produced in 1996 and a projected 115,760 acre-feet of effluent by the year 2025.
However, a lack of distribution systems, jurisdictional issues and a lack of suitable recharge sites restrict the number of golf courses that can use this renewable water supply. Only 13 of the 38 golf courses in the Tucson Active Management Area use effluent. Randolph
and two other golf courses use some effluent in combination with groundwater. The other 22, including Omni Tucson National Golf Course, are completely dependent on groundwater, which accounts for 58 percent of local golf course water use.
"The infrastructure is a really big part of it," said Laura Grignano, water resource specialist at the Arizona Department of Water Resources. "Most of the time there isn't a system that goes to the golf courses. You have to build the infrastructure to get the reclaimed water there."
As an incentive for those golf courses that have effluent water at their disposal, each acre-foot of effluent used is only counted as 0.7 acre-feet. But golf courses that use only effluent, without any groundwater, don't have to meet their annual water allotment requirement at all.
"We can't regulate them," said Grignano, "but if they use one drop of groundwater, then their allotment counts ... they have to meet their allotment."
This tack for effluent water use seems to be working. As of the year 2000, golf courses accounted for 72 percent of effluent water use, up 38 percent in 1990. "I'm encouraged," said Grignano.
With strict water use guidelines, strong incentives and a further development of effluent distribution systems, effluent water use can be expected to grow. Golf resorts can--and should--be expected to further employ the growing population's treated wastewater instead of consuming precious groundwater.