Irrigation meters can save money (copy)

Lawn-watering can lead to high water bills.

Some Mount Pleasant residents are probably overwatering their lawns, and they’re paying for it unnecessarily. But there’s more at stake than just dollars and cents.

Not only is overwatering wasteful, it can push Mount Pleasant Waterworks to buy more water from Charleston Water System, which also puts pressure on rates, and it puts a crimp in MPW’s efforts to reduce groundwater withdrawals from a critically important aquifer.

During a dry spell this past spring, water usage in Mount Pleasant spiked about 20% beyond what it typically does that time of year. Thanks to an advanced metering system that enables MPW to drill down to usage per hour, the utility determined the primary cause was irrigation.

One single-family home went way beyond the 300-gallon-per-day allowance every two to four days from mid-April through mid-May, and the monthly water bill roughly tripled to an astounding $342.

Like most utilities, MPW has tiered usage rates. Once a single-family home exceeds 300 gallons per day, or 9,200 gallons per month, the rates double, then triple when usage exceeds 18,400 gallons. Rates quadruple beyond 27,600 gallons.

By contrast, another comparable home weathered the drought in good shape, exceeding the 300-gallon limit for only four days. That bill came in at $122.

Of course, overwatering isn’t limited to Mount Pleasant, but the need to conserve water in the area is the greatest regionally. And cutting back on lawn watering is the easiest place to start.

Even during periods of drought, sandy-soil lawns shouldn’t need watering more than 1/2 inch twice a week and clay-soil lawns about 1 inch once a week, according to Clemson Extension Service, which has tips on keeping lawns greener while conserving water.

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MPW offers a free household audit that can help identify not only waste from overwatering but leaks in water systems. For more information, see the MPW website or call customer service at 843-884-9626.

Perhaps the simplest way to check your lawn for moisture is to take a step in the grass. If it springs back into place, it’s OK. If not and it’s tinged a bluish-gray, it needs watering. Another quick test is to sink a screwdriver into the lawn. If it goes in easily to a depth of about 6 inches, you’re good. If it’s hard to push beyond 3-4 inches, it needs watering.

Don’t just set your sprinkler system and forget about it. Turn it off when rain is imminent and fine-tune the system to deliver only what the lawn needs, preferably around dawn. A rain barrel attached to gutter downspout also can go a long way in reducing water usage.

Following good water conservation habits now will help keep rates from rising too much. It also will aid MPW’s efforts to preserve the aquifer. Both are good reasons to be mindful when you water your lawn.

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