My main expertise is in water movement and wastewater treatment in the field; I especially love applied science that works for the professional in the field. I invented the Aardvark Borehole Permeameter and Soilmoisture heard about my invention and contacted me. I was truly impressed with their flexible technical staff who, after much work on their part, turned my design into the world's only automated Borehole Permeameter: tough, portable, reliable, highly accurate, and complete with software. Still known as the Aardvark, it is now sold worldwide through their extensive global network. I am proud to have my name and invention associated with Soilmoisture Equipment!

Thomas Macfie,
Inventor of the Aardvark Permeameter

Home :: Serpent in Eden

Serpent in Eden

excerpt from the Soil Report Newsletter of Soilmoisture Equipment Corp.

California's Central Valley qualifies as an Eden, a lush garden, truly one of America's wonders. Every time an American sets down to a meal, chances are he is eating something grown in the Central Valley.

But America's Eden is now being threatened by the very thing which made it--water, or better said, the soaring costs of water.

Tom Newkirk explains the problem. He is irrigation manager for Fruit Growers Supply co-op in Woodlake. Lots and lots of oranges and olives are grown around there, and Fruit Growers Supply, a division of Sunkist, furnishes everything from packing boxes to irrigation advice.

"Historically the Central Valley always had water. Tule Lake and the San Joaquin River seemed inexhaustible sources. But the water wasn't always where and when it was needed. The problem was water management.

"For a long time the problem was solved by well-drilling and everyone prospered. But by 1950 the valley was in danger of becoming a desert. The water had been used up. The water table was down to 200 feet and dropping.

"At that time the valley was saved by building the Friant-Kern and other canals, diverting water from the north and east to where it was needed."

This seemed to end the water problem, but now it has returned in another form.

"There is still some well water in the valley, " Newkirk explains, "but most water comes from the canal, meaning it comes from state and federal sources. There are two delivery systems, pressurized through pipes and gravity flow, called Class 1 and Class 2 water. Class 1 is treated and drinkable, gravity flow is not."
Obviously there is a big difference in price. Treated or Class 1 water costs about $50 an acre foot, gravity flow water costs about $36. Farmers have no choice among the systems, but must accept whatever is installed in their area.

Tom Newkirk reduces these numbers to terms we can all understand. "An acre foot, that is, the amount of water it takes to cover an acre of ground to a depth of 12 inches, equals 326,000 gallons. You can't grow anything on an acre foot of water. Most orange groves require two and a half to three acre feet per acre per year. That's roughly $100 per acre. That does not include the costs of pumping the water."

What worries Tom Newkirk and every farmer in the valley--and ought to concern everyone who goes to a grocery store--is a simple fact. In 1990 Class 2 or gravity flow water cost about $12 an acre foot. Costs have tripled in five or six years.

"I don't foresee the rising costs of water stopping for quite awhile. Many of the canals and delivery systems are 40 years old. Just recently Orange Cove had to replace 110 miles of pipeline at a cost of millions of dollars."

Then there is the increased competition for water. Los Angeles and San Diego want the same water, both for farming and for urban development.
All this means is that to curtail rising costs of water and remain competitive, growers must conserve water and use it wisely.

Tom Newkirk: "I doubt if many growers will go for a computerized, fully automated system like Dave Koontz has in Ventura County, but it isn't necessary. Gauges can be read and irrigation begun when needed.

"There is no doubt the Soilmoisture tensiometer is the best solution to the problem. It tells a grower when to water and how long. We sell them here at Fruit Growers Supply. The cost only about $40 apiece and the grower needs only one or two per 10 acres, a small investment producing a big savings. Yet, only 20 to 25 per cent of our growers hereabout make use of tensiometers."

Newkirk says some growers are on a schedule, that is, they can tap into state and federal water only on certain days. If they don't use it they lose it. Other growers have an allotment, meaning they have paid for a certain amount of water and they might as well use it. But some growers have a "seat of the pants" mentality, as he calls it when it comes to watering.

"They've been doing something all their lives," he explains, "and it seems to work. They decide to water on the basis of temperature, by looking at the soil or tree. Perhaps they see their neighbor watering. Since he's a good farmer maybe they better water, too.

"It is simply hard to believe that technology, a number on a gauge, works better than something you've relied on all your life. I've seen growers buy a tensiometer and try it out, but it is soon abandoned. Maybe the gauge says don't water, when all the signs point to the need and their neighbors are all irrigating. Or, maybe the gauge says to water when nobody else is. Using a tensiometer, trusting technology over your own hard won instincts, takes a leap of faith."

But it is a leap farmers and growers may have to come to in an age of high-priced water.