Energy Adviser: Water-saving ways to keep lawn green



Wondering the secret to a lush, green lawn even in the high heat of summer? The easiest and most efficient way to keep your yard beautiful during the hottest days of the season is to water early in the morning or late in the evening using sprinkler timers or an automatic sprinkler system.

While it’s tempting to turn on the hose and spray when the afternoon sun is shining, watering in the midday heat means a big percentage of water evaporates before ever reaching your plants’ roots.

Clark Public Utilities cares about how much water you use on your grass, shrubs and flowers because the utility provides water to 30,000 customers in Clark County and we all play a part in keeping our water supply safe and plentiful.

Doug Quinn, director of the utility’s water services, explains that customer usage jumps from 8 million gallons a day during the cold winter months to 30 million gallons a day in July and August. The water does not come from reservoirs fed by streams, as in Portland, but instead is pumped from aquifers deep underground.

Making some changes to when and how you water can help reduce the amount of water needed to keep your garden green and, in turn, reduce your monthly water bill.

Sprinkler options

Using a faucet timer attached to an outdoor hose is the least expensive way to get watering done during those cooler prime hours at dawn or dusk.

More elaborate in-ground systems can run around $2,000 or more if you hire a designer to lay out your system and a contractor to install it. Digging the trenches and installing the system yourself can save you more than half the cost of putting in sprinklers, but it’s a good idea to consult a professional during the planning stage to make sure the system is set up to function optimally.

Al Sievers of Al Sievers Sprinkler Services, which operates in Clark County, said the biggest mistake homeowners make when installing an in-ground system is “not understanding basic hydraulics” in terms of water pressure, gallons per minute and zone pressure. “The majority of our work is repairing or tearing out a system that’s been installed by someone else,” Sievers said.

In-ground systems are typically designed to water sequential “zones” using 15 gallons per minute of water flow.

“Designing a system is a lot more than just laying out pipe and sprinkler heads,” said Cindy Webb, president and owner of Right Irrigation Supply Inc. in Vancouver. “You’ve got to determine the water available to the system, the pressure, meter size or gallons per minute from a deep well. Then you have to ask what each zone will be watering. Some areas may need more water than others.”

Webb recommends using drip tubing to water everything but grass. “Drip watering is the most efficient, plus lots of flowers and shrubs don’t like spray watering,” she said. “Drip also helps with weeding by putting water only in areas that need it.”

Estimating coverage

Many people adhere to a formula of one inch of water per week for keeping grass green. Sievers said that’s not a hard and fast rule because of varying conditions.

Quinn encourages all homeowners to be conscientious when using water during the summer. “We see some incredible spikes in demand when people start watering their grass and filling their swimming pools.”

He said Clark Public Utilities water customers concerned about their water bills or other water issues can call the utility at 360-992-8022 and request a “water audit.” The utility will send someone to the property to take a look and see if there are ways to save.

As for property value enhancement, Vancouver Realtor Gerry Dowdy said an automatic in-ground sprinkler system “should be there” in higher-end homes in the $400,000-plus price range.

The Energy Adviser is written by Clark Public Utilities energy counselors, who provide conservation and energy use information to utility customers. Send questions to