Flipping a wall switch in his family room, Ellicott City homeowner Chuck Wadsworth turns on water, not light. The naturalistic waterfall in his back yard comes to life as a trickle becomes a steady stream cascading down tiered stones to disappear behind large rocks.

“It’s the centerpiece of the yard,” says Wadsworth, a software project manager. “It catches your eye and pulls you in.”

He and wife, Jill, recently completed the waterfall with its remotely activated pump as part of an extensive, $150,000 renovation of their hilly garden. After terracing the slope with stone walls, they added a new deck with an endless pool and a spa, a patio with a fire pit, and an outdoor kitchen with a fireplace and a brick oven.

“The waterfall brings it all together,” says Jill Wadsworth, a managing director of a company specializing in employee recognition strategies. “It looks very natural, like it is almost coming from a brook. When we get up in the morning and walk into the kitchen, it provides a beautiful view.”

Such aquatic designs offer not only cooling reminders of creeks and rivers but also relief from the daily stresses of work and family. “The sound of water is incredibly calming in the hectic lives led by a lot of Washingtonians,” says real estate agent Kimberly Cestari of W.C. & A.N. Miller Realtors. “In the right setting, fountains and small ornamental pools set amid other nice landscaping add value to a property.”

The sound of gurgling water can also make owners and potential buyers forget about a home’s proximity to a noisy street. For attorneys David and Deborah Astrove, a bubbling fountain drowns out the traffic sounds from a busy boulevard near their Bethesda home.

“It’s so tranquil,” says Deborah Astrove of the backyard pool. “When you are sitting on the patio or porch, your eye goes right to the water. Visually, it holds the whole garden together.”

The limestone-rimmed basin punctuates the end of a long lawn framed by boxwood shrubs and hornbeam trees. “It’s a destination point, a place to walk to,” says District landscape architect Cynthia Ferranto, who designed the Astroves’ pool and garden. “It makes you feel cooler to see and hear the water and know that it is there.”

But backyard water features can be fraught with problems — mosquitoes, clogged filters and leaky liners, to name a few — that require costly attention. “Be prepared to spend money on maintenance that you may not recoup when it comes to selling your house,” says Morgan Knull, a broker with Re/Max Gateway.

Moreover, Knull says, many house shoppers are put off by the sight of a fish pond or a fountain, no matter how well they are designed. “Buyers are often intimidated when it comes to their maintenance.”

That upkeep includes cleaning filters and basins, ensuring pumps are working to move and aerate the water, and replenishing moisture lost to evaporation.

But with the right planning and design, experts say, fountains can run smoothly — even year round — to mimic the sights and sounds of nature. “If it is properly built, the water feature will not require a ton of maintenance,” says Donald Jump, vice president of Lorton-based Harmony Ponds Inc.

The key to keeping the water clean, he says, is aquatic plants. Water lilies, water hyacinths, cattails and other vegetation increase oxygen levels and filter and shade the water. “The more plants, the cleaner the water will be,” says Jump, who says that 65 percent of the water surface should be covered with plants.

Goldfish can contribute to the health of a pond by eating mosquito larvae and algae, he adds, noting the fish require water at least 18 inches deep. In the Astroves’ yard, the pool is 21 / 2 feet deep so the water doesn’t freeze — and the fish are kept alive — during winter months.

Without plants and fish, some ponds and pools can suffer from too much sunlight and low oxygen levels, and, as a consequence, an abundance of slimy algae. Such was the case recently in the backyard reflecting pool behind the Bethesda home of art consultant and interior designer Judy Weisman, who remedied the problem by adding chemicals to the water.

Weisman’s modern garden, designed by Annapolis landscape architect Kevin Campion, centers on an L-shaped basin and adjoining rock garden placed next to a sculptural Japanese maple. “A calm body of water like this reflects nature and brings the tree into the ground plane in a beautiful way,” Campion says.

Steppingstones extend across the eight-inch-deep pool to connect the two sides of the patio. The granite pavers are supported on submerged concrete piers and illuminated by strips of light-emitting diodes (LED) so they appear to float on the water. Hidden in one corner of the pool is a submerged pump to circulate the water.

Weisman would not divulge the cost of the project, but Campion said a poured concrete reflecting pool measuring 10 feet by 20 feet runs about $15,000 to $30,000, not including design fees.

Do-it-yourselfers can create a less expensive water feature by setting a synthetic rubber liner into the ground and adding a pump, piping and filter, all for about $1,500, according to Jump. Homemade fountains combining an urn, a pump and a water spray at the top, he says, can cost about $750 to $1,000.

Large ponds and pools are best left to the pros because they require more complicated plumbing and electrical work and the artistry to make rocky edges and waterfalls appear natural. Their successful operation is dependent on choosing a pump capable of regularly turning over the volume of water and strong enough to push the water to the top of a fountain or a waterfall.

“There is more to installing a fountain than meets the eye,” says Keith Powell, a ship broker, who with his wife, Marianne, a homemaker, recently added such a water feature to the walled garden behind their Embassy Row townhouse. “My advice is to start the project after you’ve figured out the whole system of mounting the fountain, draining and cleaning it, and determining the power source.”

For the Powells, the process started with a marble fountain shipped from Florida. So the design could stand independently of the brick wall behind it, the pedestal of the fountain was mounted on a newly created limestone base. The basin has a spout at the top and a drain like a sink, leading Keith Powell to plug the hole and tinker with the design so the falling water makes a splashing sound.

Water now pours from the spout to fill the basin where the overflow drains into an upright copper pipe. The pipe is connected to tubing extending to a tank buried in a corner of the yard. From the underground tank, the water is pumped back into the fountain to start the cycle all over again.

“We couldn’t find anything on the market that did this so we did it ourselves,” says Powell, who spent about $5,500 on the fountain, related mechanisms and installation.

To avoid the maintenance headaches of a conventional pond or fountain, the Wadsworths built their waterfall so the water runs down to a stone bed, where it drops through openings into an underground tank with a pump.

“We went with a pondless waterfall because there are no fish to take care of, no algae, no leaves to clean out,” says Chuck Wadsworth.

He is still fine-tuning the arrangement of rocks along the water course and finishing other parts of the yard with the help of a local firm, aptly named Low Maintenance Landscaping.

Deborah K. Dietsch is a freelance writer.