So what is a water audit? Do you need one? How does it help? How can it save money? Let’s take this one step at a time…
Water audits involve the inspection of an irrigation system at some point after it’s been installed. In essence, it’s a snapshot of how your irrigation system is working at a given time.
But how do you know if you need to conduct a water audit? Usually, there are tell-tale signs. Water running onto pavement and into the streets, an increase in a property’s use of irrigation water over a period of time, a complaint made to your local water district by a neighbor; all are signs that the property has a problem. If you think you should monitor it, the property probably needs an audit of the water usage
There are three basic parts of an audit. The first step is an analysis of the property’s water use patterns. That involves weather data and the historic water use patterns of the site.
Next is a visual inspection of the system while it’s running to ensure that each component is operating properly. This is where you’ll probably find the source of many of the system’s deficiencies. Often, the repair is simple: a misaligned sprinkler head or one with too much range; the wrong nozzle; a blown riser.
It’s imperative that these maintenance problems be addressed before performing the third step, which is a performance test. If the system isn’t working properly, a performance test is really a waste of time, defeating the whole point of an audit.
Once the irrigation system’s deficiencies have been addressed, it’s time to check and see if the sprinklers are providing uniform coverage. The easiest way to see how uniformly the sprinkler system is working is to use catch-cans within the coverage area.
These catch-cans are placed throughout the zone that’s being evaluated. The water is turned on, let’s say for five minutes; then the amount of water is measured in each catch-can. If there are big differences in the amount of water in each catch-can, then there is a problem somewhere.
Now you may be tempted to do this on your own instead of hiring an expert. But that could prove to be penny wise and pound foolish. There’s more to evaluating an irrigation system’s efficiency than looking at water in a cup. And creating an efficient watering schedule that conserves water takes some training in how to interpret the data you’ve collected.
It’s those watering schedules that Brian Vinchesi, of Irrigation Consulting, Inc, Pepperell, Massachusetts, says are the greatest benefit of a water audit. He describes a water audit as a scheduling tool, a field test of an irrigation system that’s designed to show its distribution uniformity and precipitation rates. From the data collected, a base schedule for the system is derived.
Another firm believer in the effectiveness of water audits is Tim Wilson, of H2O Stewardship Solutions in Cheney, Washington. He’s done hundreds of audits and says the goal is to correct the system by looking for weak spots and fixing them. After correcting the system, he also recommends creating detailed watering schedules and then keeping things watered evenly. In simple terms, a water audit should teach people how sprinklers apply water.
Incredibly, even after conducting an audit that shows where improvements can be made, saving water and money, there’s a tendency for both property owners and landscape contractors alike to fall back on old habits and start wasting water again. “They mean well,” says Wilson, “but don’t follow through because of budgetary restraints. They don’t have the capital.”
A study in the Contra Costa Water District in Northern California found that many audited sights eventually deteriorated to pre-audit levels because they didn’t maintain the improvements. “In theory, if someone has fully implemented the schedule, it will save water,” says Wilson. “The problem is in the implementation… they use parts of the audit, but ignore others.”
Often, the problem is just a question of maintenance. Chris Willig, of Environmental Water Management, Agoura Hills, California, says that over 80 percent of the changes, repairs and maintenance he recommends after an audit are relatively small. He feels that if landscape contractors do their systems checks frequently, they would run across these deficiencies before they become problems. “I think those systems checks are critical in keeping the number of problems relatively low.”
It’s also important to realize that a water audit is not the “end all to be all,” and that it should be part of a comprehensive plan. “Put together a site management plan,” says Wilson. “In the long run, it will save money and there will be a payback, a return on the investment.” And while a site management plan is usually developed before construction begins, it can be done on a pre-existing structure. A water audit should be one piece of that site management plan.
A complete irrigation system audit should also include the evaluation of plant material within the area that’s being watered. The depth of active roots, soil consistency, and evapotranspiration rates are also factored into the equation to ultimately determine how many gallons per minute are being used by the sprinkler system, and the water usage in each zone of coverage. Those are all factors a certified auditor will take into account.
It is important that the person who does your water audit be certified. There are many variables facing an auditor of a landscape irrigation system, as opposed to the uniformity found in most agricultural systems. “When you get into landscape,” says Willig, “you now have variable spacing, different heads, and variable plant materials.”
For example, usually five or six catch-cans per acre are sufficient for auditing water use on a large turf rotor system. When auditing landscaping on a residential or commercial property, anywhere from 20 to 30 catch-cans stations per acre are needed. To accurately determine how well a sprinkler system is working, Wellig says it’s essential that an auditor take representative samples from all the irrigation zones, and take into consideration the sprinkler heads being tested. Different heads will perform at different rates.
Even the experts can have a hard time with all those variables. Currently there aren’t any uniform guidelines for auditors to follow. Consequently, there’s a lack of uniformity in the results that can be derived from auditing the same property. “You might have three different audits on the same site,” says Vinchesi, “and you won’t get the same results because each audit was done differently.”
The Irrigation Association has developed guidelines that are currently under review. Once a standard is in place, there should be more uniformity as to how audits are done.
So now that a water audit has been conducted, what’s next? Often the fix is relatively simple; occasionally, it involves more costly and time consuming repairs like replacing parts of the irrigation system. Unfortunately, the desire to save money, which leads property owners to conduct a water audit in the first place, often motivates them to ignore implementing the changes necessary to make the audit cost effective.
As budgets tighten, property owners and managers have to make hard choices. That often translates into a more “bang for your buck” mentality. With rising energy costs, water conservation is not always a priority. Especially on commercial properties, where the emphasis tends to go towards energy conservation, and there seems to be a greater savings by cutting back on a huge electric bill versus the smaller savings found in efficiently irrigating that property.
However, there could prove to be folly in that thinking. Water sources don’t always remain constant. Aquifers can become depleted. Drought can quickly ravage regions where water was once abundant. And the price of water is always going up. The long-term benefits of water conservation far outweigh the short-term savings found in putting resources elsewhere.
There are also lots of other problems caused by wasting water that could cost a property owner much more than the initial price of repairing an irrigation system. Things like the destruction of wood fences and supports, asphalt deterioration, paint damage and building settlement. Avoiding those potential consequences of not maintaining the system should be reason enough to conduct an audit.
“What we try to do is identify the dollar savings that we think are available on the site,” says Wellig. “That allows the customer to evaluate the bids they may get on these upgrades and maintenance issues. So getting a handle on the potential savings in dollar terms is critical. The objective is to allow the customer to understand the water use and make better decisions on how they want to spend their landscape maintenance dollar. And that’s really what a water audit is… a mechanism for the customer to really understand how they’re using their water.”
In many instances, the costs for minor repairs should be included in the landscape maintenance contract. When the costs for repairs are more significant, that’s when the landscape contractor needs to be proactive. A well-done audit will help you convince the property owner that the savings in water conservation will far outweigh the initial outlay of capital.
A good place to find a qualified auditor is the Irrigation Association. They are responsible for certifying auditors, and they maintain a list of who’s qualified to do audits in your area. Some irrigation contractors also do water audits, but there could be a conflict of interest if the person you hire to repair the irrigation system is also the person telling you what’s wrong with it.
To avoid that dilemma, it’s probably best to hire an independent, certified water auditor. Wellig says his company does not do design or repairs to avoid the implication of a conflict of interest. “All we do is go out to a site, evaluate the water use, look at the system, and prepare a report that would help the customer make a decision. They hire somebody else to deal with repairs to the system, the redesigns, whatever it entails as a consequence of the inspection and the testing.”
More often than not, a water audit should pay for itself. But for the audit to work, it’s important that it be done right, and that the recommendations made are implemented and maintained. “If someone does an audit,” says Wilson, “and makes improvements so water is distributed evenly, if they develop detailed watering schedules, if they implement those watering schedules, and if they update those schedules according to weather changes, and then if they keep regular maintenance on the system to keep it watering efficiently… then yes, water audits work.”
In the long run, that will save your client money, and that makes you look good.