Water features enhance the landscape
It is raining heavily as a northern Illinois homeowner turns off the main road and drives down a private access lane. He drives over a bridge spanning a stream, as well as a waterfall that connects two ponds, before pulling into his garage.
The ponds at this site look natural but are actually man-made. So is the waterfall. What's more, a submersible pump recirculates water from the lower pond to the upper pond. The ponds, which are visible from the house, serve more than an aesthetic function. In fact, our firm designed and built these two ponds, the stream and the waterfall to control flooding on the 14-acre property. The retention ponds are on the lowest portion of the property where water naturally collects.
While we created this water feature to solve a specific flood-control problem, other homeowners ask us to build water features simply because they love water in their gardens. A pool of water can be calming. Plus, running water, such as a stream or a waterfall, creates a delightful sound that can mask undesirable noise on a property's perimeter, such as automobiles on a busy street or children playing in an adjacent playground. Besides its ability to mask noise, a water feature can be a garden focal point. Splashing water, such as from a fountain, appeals to a homeowner's sense of sound, sight and touch.
Water in the garden has universal and historical appeal. The Moorish gardens of the Alhambra in Granada, Spain, date from the 13th century and are perhaps the finest example of how to introduce water to a garden. In more recent times, homeowners are becoming more interested in adding water features to enhance their home landscapes as they spend more time at home. Corporate sites add water features to outdoor landscaped areas to give employees a relaxing area to eat lunch or to greet visitors.
Our clients in northern Illinois and southern Wisconsin are no exception to such trends. They, too, want water features designed into their landscapes. After all, the terrain in this part of the Midwest is perfect for water features. The Midwest landscape is all about vistas and sky. And because we don't have mountains or oceans, we can fulfill our desires for additional environmental beauty by adding fountains or ponds as focal points.
But the Midwest climate is harsh. For that reason, we don't favor fountains in the Midwest simply because the weather limits their use from essentially May 1 to October 1. Midwesterners then must cover them over the winter months. They aren't much to look at when wrapped in brown protective plastic. Admittedly, you can build fountains to operate year-round by adding antifreeze, for instance, or heating elements. But then homeowners run the risk of an electric pump failing or electricity going out, leading to frozen and burst water lines.
When we do build a fountain in a residential setting, we like to see it finished with tile or otherwise detailed. A fountain should be an architectural element in the landscape. But, rather than fountains, we favor ponds, streams and waterfalls.
Management concerns Regardless of whether you build a fountain or a pond, you have management issues whenever a design introduces water into the landscape. For instance, the maintenance crew now must consider how to keep the water clean, how to maintain safety in and around the water feature, how to size pumps and filters properly and how to maintain this equipment. In addition, water can attract animals to the property. Tadpoles, frogs, raccoons, deer and water fowl can make a pond their watering hole. The thing to remember is that a water feature will become a permanent part of the landscape. Therefore, before installing a water feature, the landscape designer must educate the homeowner about some of these issues, especially safety and maintenance.
Construction techniques Our design philosophy regarding water in the garden is to create features that appear as natural as possible. In doing so, you'll typically use one of three primary methods for pond construction: * A natural, or earthen, bottom * A rubber liner * A cement shell, using Gunite, a material commonly used in swimming-pool construction.
In some cases, we have used combinations of these techniques. For instance, at the northern-Illinois application described at the beginning of this article, the ponds have natural bottoms while we installed the stream and waterfall with liners.
In building a pond, you first stake out the area and the shape of the pond, then excavate. We will hand dig a pond, especially if it is near existing trees or other plant material. We also use earth-moving equipment, such as a front-end skid-steer loader or a backhoe.
Among these three methods, Gunite is the most expensive, but well worth it in our experience. A cement shell creates a water-tight bottom that is more durable than alternatives. A Gunite shell, therefore, produces a more permanent pond. It is similar to building an in-ground swimming pool. You also can use Gunite to create a waterfall. In waterfall construction, we first build a form, then apply the cement.
Don't forget to build an overflow drain in your pond to handle excessive volumes of water from rain, snowmelt or flooding. An overflow drain in a man-made pond resembles its counterpart in a bathroom sink. Drain holes, set at the desired height, direct excess water away from the pond. If codes permit, we prefer to drain to a city storm sewer. Other options include draining to a dry well or channeling the water to a low-lying area.
To make manmade ponds and streams look more natural, mortar rocks to the pool bottom or stream bed. You can color the mortar during application to hide the joints. You also can use natural rock and stone around your water feature to enhance its appearance. We've used Wisconsin granite, Minnesota gun-metal granite and Marshfield boulders (a fieldstone from Wisconsin). Man-made rocks, which look quite natural too, also are available. You can form these to fit your site's specific needs.
Water appears clear in a pond with a cement liner. You also can paint the pond bottom to achieve other effects. For example, white paint makes the water look blue because it reflects the sky. Other colors give more of a murky look, if that's what you want to achieve, while black gives the appearance of greatest depth. We use paint as often as possible to darken water, rather than using chemicals, to keep the water feature as natural as possible.
As mentioned, you also can build ponds using a rubber liner to hold the water. This is a more economical alternative, but it comes with some risks. The primary risk is that something (a stick, rock or human error) can puncture or tear the liner, resulting in a leak. This will result in leaks to the soil around the pond. Though the leak might be slow, and the decrease in water level may appear to be imperceptible, the water eventually will saturate the surrounding ground. Some nearby plants won't be able to tolerate such conditions. But with care in handling the liner, you can avoid this problem.
If you use the rubber-liner method, you first lay down a woven polyester mat after excavation, then place the rubber liner over this mat. The polyester liner serves as protection from the excessive weight of the water. But it also acts as a filter for ground gases. A pure rubber liner locks in gases and forms bubbles.
When building a pond, extend this liner out and away from the pond, then cover it with soil or rock. Extending the liner allows the gases to escape without bulging the liner.
Another advantage to a rubber liner is that it can take some movement from frost-heaving.
Rubber liners come in sheets as large as 200 by 1,000 feet. We like to work with one piece of rubber, although kits are available that allow designers to patch together two or more pieces. By working with one large piece, however, you avoid the potential for leaking at the seams. When cutting a liner, it is important to allow for about an extra 15 feet of width so that the liner can extend as far out the sides as you desire. Once you've installed the liner, then you can cover it with soil and rocks.
With the bed completed, it is time to fill the pond with water. The ponds we have built have been filled by natural springs, by wells, by garden hose and by rainfall. We also have used irrigation systems to fill ponds. In these situations, an automatic-fill system with a float activates the sprinkler system to top off pond levels when needed. When you fill a pond for the first time, you have to wait for this newly created ecosystem to get into balance. This can take as little as a day or up to a month. If you're in a hurry, you can add powders to the water, which knock suspended particles to the bottom of the pond. Or you can wait for nature to take its course.
Algae and pond maintenance Building codes often determine the slope and depth of the pond. Some codes require a safety shelf, which basically is a shallow ledge around the pond's perimeter to protect children from falling into deep water. You'll need to contact your local building department to find out what codes apply to your situation.
These ledges also come into play when deciding which plants to use. This is because water over a ledge warms up faster than water in the center of a pond. This can create algae blooms that homeowners may need to skim off. It also may cause you to purchase different plants to grow along the ledges compared to plants that can grow in the deeper sections of the pond. A nursery that deals with aquatic plants can provide more information on which species to consider.
Algae blooms, as mentioned, can be a problem in small ponds. They are a function of sunlight, temperature and mineral content of the water. Some plants that grow in ponds, such as grasses and certain lilies, contain natural algaecides. These are suitable for controlling algae growth. Of course, you also can use commercial algaecides, too. And a filter system also aerates the water and prevents or inhibits algae growth. With extreme algae growth, a maintenance crew might have to rake off the blooms once a week.
Filtering systems are an important component of any pond or pool. Water will stagnate if it is not recirculated or otherwise aerated. Filters keep water clear and clean, and pumps regulate water level. We use submersible pumps in most of the ponds we design and build. Submersible pumps are a plus because they are out of sight and so quiet as to be imperceptible. In some installations, we build a pit for the pump on the bottom of the pond. On other jobs, however, we place the pump off to the side and run water through PVC pipes.
Maintenance needs of the pump may determine where you place it. After all, you need to clean and check both filters and pumps on an annual basis or more frequently, depending on water quality. Also, maintenance crews must be able to get at pumps easily to repair them or to pull them out in the winter time, if necessary.
Ponds give a residential landscape a special quality. But, as we have explained, building a pond is not quite as easy as simply digging a hole. The designer has to consider maintenance, safety and aesthetic issues.
Scott Byron is president of Scott Byron & Co., an award-winning landscape design and maintenance firm based in Lake Bluff, Ill. The company received the highest award from the Association of Landscape Contractors of America in 1997.
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