Considering Water Conservation During Irrigation Renovations

Source: www.TurfMagazine.com

Conserving water through smart irrigation design and high-tech tools isn’t just a matter of theory. It still takes good, old-fashioned problem-solving to go from design to an installed system.

“The easy part is the design; the hard part is making it all work,” says Peter Estournes, a certified landscape irrigation auditor and vice president of Gardenworks Inc. in California.

A great example of this is a project the company currently has underway to completely renovate the landscape and irrigation system at a commercial site where a new microbrewery/restaurant is going into an existing building. The challenges began right away.

“We had to meet the Model Water Efficient Landscape Ordinance requirements for the project as part of the permit submittal process,” says Estournes, explaining that this California ordinance is not new but is now required by building code requirements. For all intents and purposes it is now code, and it’s triggered in any time there’s a building permit, plan check or design-review undertaken, providing the landscaped area is greater than 500 square feet.

“That created an extra burden for the design process of having to calculate your hydro-zones, your water needs for the year and a maximum applied water allowance,” he states. “As part of that, we ended up having to investigate the existing irrigation system, which again cost extra hours because typically in a landscape design you’re not investigating an existing system, you’re putting in a new system.”

The Model Water Efficient Landscape Ordinance requires the submission of a soils report, and this particular site was found to have an expansive soil. The testing process also took time and additional money. (At least in California, more and more landscape contractors, especially those working in the commercial arena, are going to have to go through these same processes, notes Estournes.)

In investigating the existing irrigation system, the Estournes team discovered that the main line needed would prevent the expensive prospect of having to tear up existing sidewalks and parking areas. “It turns out that the existing system was a combination of spray and drip; the drip had no filter or pressure regulator, so we’re going to basically cut back to the main line, keep the irrigation controller wires and then revalve from there,” he explains. “The entire landscape will be put on drip with a low to very low water-use landscape palette to meet the MWELO standards. And because of the new standards, we now have to add isolation valves or shut-offs at each valve location, and we have to make sure there is pressure regulation if needed. We also have to put in a new weather-based irrigation controller upgrade, which will be a challenge because the one that is there now is cut into a wall and the new controllers don’t fit that, so we need to figure out how to patch the wall. And, not only that, but the new configuration may mean that wires don’t reach.”

All of this is to say that, between normal practical challenges in the field and new regulations, there’s a lot of work involved in the installation of a more efficient irrigation system. And it also means that a lot of care must be taken in the bidding process to be sure that all facets of the job are accounted for.

Gardenworks is handling both the irrigation system and the design of the landscape, giving assurances that each plant selected will receive the proper amount of water. Though, as Estournes points out, in this era of water conservation, the order of operations has really flipped.

“We used to design the plant material and then design the irrigation system. But now you have to design the irrigation components ahead of the plant material and then make the plant material fit the water budget — it’s a paradigm shift,” he explains. “We’re having to rethink the process, so that the name of the plant isn’t as important as its water use classification.”