Rainwater already can help water your lawn and may even help flush your toilet or run your washing machine if a proposal the N.C. Code Council is studying passes, both offering creative solutions to the ongoing drought.

Underground irrigation systems with huge holding tanks that capture rain, sometimes supplemented by well water, can water a lawn as well as traditional systems, said builders and owners of the companies that provide the service.

“It’s something that’s new, though the technology’s been used for thousands of years,” said Zebulon builder Chad Ray. “There are companies that are providing the service and we are starting to get requests for them.”

And builders and developers are packing meetings run by the Home Builders Association Green Building Programs to find out about the systems, said Mike Ruck co-owner of Rainwater Solutions. The Raleigh company Ruck owns with his wife Lynn was a site of one of the meetings recently.

As far as rainwater possibly being used in homes, Triangle builder and co-owner of FreeRain, Rex Bost, said he has submitted documents to the N.C. Code Council that show how this can be done. He said the documents contained information based on studies done around the world. Bost was an ad hoc member of the council’s committee that wrote a new code to allow the practice. The N.C. Code Council is considering the passing the new code, but hasn’t acted yet, Bost said.

Bost, also of Bost Custom Homes, said nearly half of the water used inside a house comes from running washing machines and flushing toilets.

Rainwater Solutions Ruck said he and his wife started their company first as a hobby, making rain barrels. Now he’s getting calls every day from builders who want to install the underground systems, he said.

Cimarron Homes, a green builder of more moderate priced homes in Durham (Homes range from $140,000 to $300,000), is one of his recent clients. The company installed a rainwater irrigation system at the model home at its new development Stagville at Treyburn in Durham.

“This home will be in the May 2 and May 3 Green Building tour. It’s another feature we’ll be bragging about in that tour,” said Dan Winters, purchasing manager with Cimarron Homes.

The feature will be offered for the pickings in homes the way buyers select countertops and flooring, Winters said.

“We’ve certainly been interested in it,” he said. “The drought has forced everybody to do things smarter.”

Winters said the model home also will use drought-resistant plants, something Ruck recommends to all his clients to stretch out the rainwater his systems collect. Bost also recommends planting drought resistant plants.

Ray said there were essentially two different ways to fill an underground tank. He said one is gutter running off roofs fed into pipes that run into the cistern. Ray also said water can be captured by the grading of a yard.

“If you can shape your yard, you can get the water run in the direction you want it to go in and your cistern is where the runoff is going to,” he said. A hole covered by a grate will provide access to the underground tank, he added.

The rain is filtered in all systems so that it is clear of debris. Electric pumps and pipes are used to get water to an irrigation system or to a spigot where irrigation can take place with a hose.

Bost said he began installing rain collection systems for his clients nine years ago, saw the demand for it and started company with John Doughty to provide them to others.

“Obviously current drought conditions and water restrictions have sent contactors and owners scrambling for alternative sources of this precious commodity,” said Bost. “Rain barrels are a nice gesture and are helpful for hand watering. But an average half acre lawn can require 1,500 to 2,000 gallons per week to survive in summer conditions. Much more capacity is needed and much can be collected in a moderate rain event.”

Bost said for smaller yards, he recommends installing about a 3,500 gallon tank and system — as big as an SUV — with a cost of about $8,000. At large homes with big yards, he recommends a 10,000 gallon tank which can cost as much as $17,000. But he said with irrigation water bills when there is no drought run about $500 a month. Customers realize payback, some two years later and others 10 years later at current water rates and depending on the size of the tank.

The company also is trying to get cost down for more moderate needs.

Even during a drought, the tanks can collect quite a bit of water when there is only one eighth of an inch accumulation of rain, he said.

Commercial customers are interested too, Ruck and Bost both said. Bost installed a system recently at a McDonalds that wanted to collect the water running off its parking lot during showers. And a Raleigh tennis club is his latest client, he said.

“It’s not for everybody,” said Ray. “It’s definitely a luxury item. It probably does not apply to starter homes or second homes. But you can still have a rain barrel or two. It’s crazy to spend $25,000 on landscaping for a home when the plants would die without water. Because of the city water supply, the city says you can’t use the water to water your yard, and you shouldn’t. But now you do have an alternative.”