Audit Teams’ House Calls Save Water in a Big Way

With a graduated cylinder in one hand and a bizarre-looking, 2-liter plastic soda bottle in the other, Judy Mitchell plunged into the tangled branches of a lush avocado tree in a North County hillside grove.

The specially altered 2-liter bottle was placed over an active sprinkler head for 15 seconds to direct water into the measuring cylinder. Mitchell emerged with soaked jeans and a few ounces of water.

A few yards away, her partner, Margarita Engle, was measuring the water pressure of an irrigation line that helps keep the trees growing in a desert environment. As they moved from one area to the next, Engle jotted down the measurements on waterproof paper.

Mitchell and Engle were performing a water-use audit, a program funded by the San Diego County Water Authority and the California Department of Water Resources. The program’s aim is to stretch the water resources of drought-stricken San Diego County.

The service is provided free to county residents who irrigate large tracts and want suggestions on how to maintain quality plants while decreasing water use.

Over the last few years, Mitchell and Engle have trudged across thousands of acres of farmland and landscapes in the county in their knee-high rubber boots, and they are booked solid for the next few months.

“We’re not checking up on management, we’re working with them,” Engle said. “They call because it is a business, and they have to make a profit. . . . We don’t find a lot of waste, probably less than most people waste in their back yard.”

As development continues to eat up much of the flat land in the county, farmers have been moving their groves to steeper terrain, Engle said. Those areas are hard to irrigate efficiently because, without appropriate and properly functioning equipment, water pressure can vary dramatically at opposite ends of a grove.

Plants on the high end of steep groves may be getting too little pressure, while trees farther down the slope may be getting too much, Engle said. The problem can usually be corrected with inexpensive pressure regulators, she said.

Engle is the director of her two-member team from the Mission Resource Conservation District office in Fallbrook, which works throughout most of North County. A two-person team from the El Cajon office does audits in the city of San Diego and surrounding areas.

To help meet the growing demand for audits, the Fallbrook office will soon add two staffers and the El Cajon office will add one.

On this day, Engle and Mitchell were gathering data on a 10-acre grove in Twin Oaks. The manager, Robert Arnold, answered dozens of questions from Engle about the grove and his irrigation practices.

Factors such as weather, topsoil and crop characteristics will be plugged into a computer program, Engle said. Arnold will receive a report of about 10 pages, including one or two pages of suggestions for improving irrigation efficiency in the grove.

Arnold said he participated in an audit at another grove a few months ago and found the information useful.

The audits, however, have their limits, especially in professionally managed groves where water efficiency is often as high as 80%, Engle said. But even a savings of 5% or 10% can be valuable to the groves’ operators.

Noting that the small grove visited by Engle and Mitchell uses about $3,000 worth of water monthly, Arnold said that what he learns from the audit may help him save money in the dozens of other area groves that he oversees.

Though the water officials use computers in their analyses, Engle emphasized that the same water-saving tips “can be done with some simple hand calculations.”

With a $16 gauge, a graduated cylinder and a home-rigged 2-liter bottle, farmers can learn to test the efficiency of their own operations almost as accurately as the audit teams, Engle said. Although Engle and Mitchell said they enjoy working outdoors, the job occasionally can be treacherous.

Some groves are on hillsides so steep that workers have to lower themselves on ropes to harvest the crops, Engle said. At the San Diego Wild Animal Park several years ago, charging rhinos prematurely ended an audit, she said.

Mitchell, however, said her biggest fear is rattlesnakes. She said she got little comfort when once told that “they sound a lot like a sprinkler.”