Creating A Pond Ecosystem

By Erik Skindrud, regional editor

This pond in Calabasas, Calif. lost fish to a persistent blue heron?EUR??,,????'??+forcing the homeowner to add a conspicuous net. A depth of two to three feet will give pond-dwellers better protection but force contractors to obtain additional permits and inspections.

Installing a recirculating pond or stream is a relatively simple operation that in many cases can be completed in a single day. That?EUR??,,????'???s the good news. The other news, or reality you and the property owner will have to deal with, is that a pond requires regular attention to stay in a clean, attractive, balanced state.

Most contractors can follow complex instructions and build a variety of outdoor structures. The same skills can be put to use building a pond, but an additional set of knowledge is needed too, since a pond is a living system that?EUR??,,????'???s more complicated than other parts of the garden.

Pro Ponds West is a distributor whose owners and employees spent years installing ponds but now focus on supplying and educating contractors. The Costa Mesa, Calif. business got into distributing Aquascape Designs, Inc. products full-time in 1999, and has seen its business rise dramatically since then. ?EUR??,,????'??When we first got into the business there were very few natural pond builders in Southern California,?EUR??,,????'?? the company?EUR??,,????'???s Jerry McMahon said. ?EUR??,,????'??Now there are literally hundreds doing it, even though maybe 30 stand out in terms of volume.?EUR??,,????'??

 

Aquatic plant consultant Lloyd Mitchell III shows off a water hyacinth plant?EUR??,,????'???s floatation bulbs and free-floating roots. The plant (Eichhornia crassipes) helps clean a pond and provides a source of food for fish, but is invasive and should never be carelessly discarded.

The company holds regular training sessions for contractors, usually about once a month, a practice that has resulted in a lush and attractively-landscaped front of the office.

Each of the two water features there was created in about a day, with the instructors taking the time to make sure that each participant knows each step required to make things right.

?EUR??,,????'??There are a lot of contractors who have experience in what they do,?EUR??,,????'?? McMahon said. ?EUR??,,????'??But they don?EUR??,,????'???t understand how to build a pond because of the ecology involved. One thing to remember is it?EUR??,,????'???s a lot easier to do it right the first time than to go back and have to fix a problem.?EUR??,,????'??

Doing It Right

There are rules to follow, but the best pond construction will always have room for creativity on the part of the builder. For example, the demonstration pond at the Costa Mesa location is roughly 11-by-11 feet, but has an irregular shoreline intended to mimic a natural pool or pond.

The larger plant at center here is Egyptian papyrus (Cyperus papyrus). The purplish, spiky-leafed plant to its left is aquatic hibiscus, with the plumes of an iris and an elephant ear (a species of taro) to its left.

So the first step in the process is to mark the pond?EUR??,,????'???s outline on the bare earth using a can of spray marker. The crew can then start removing earth from the pool area, taking care to move the soil to the area where the water will appear to flow out of the ground. In most cases, the amount of soil removed to create the pool will be enough to create the elevation needed to make the water flow downwards on its downward course. (The pond?EUR??,,????'???s water will be pumped though a buried PVC conduit through a filtration system before emerging again from the top of the cascade.)

All ponds with flowing water will include one or more ?EUR??,,????'??steps?EUR??,,????'?? or small waterfalls. These are features that produce the pleasing sound of flowing water?EUR??,,????'??+one of the features most prized by customers.

As McMahon makes clear in classes for new customers, one thing to avoid is the temptation to make an overly-dramatic statement by creating a waterfall that?EUR??,,????'???s too high for a small pool?EUR??,,????'???s confined area. ?EUR??,,????'??You should avoid anything higher that a one-foot drop,?EUR??,,????'?? he explained. You can have a three or four-foot total elevation change, but remember to do it step-by-step so it?EUR??,,????'???s not just one big crash.?EUR??,,????'??

Keeping individual drops to a foot or less is also very important in limiting evaporation. More splash equals more evaporation and water loss?EUR??,,????'??+and more time spent refilling the pond. (Some products have sensors that will automatically maintain water level.)

Digging a Proper Hole

As far as depth, some pond experts recommend that the depth at the deepest point should be no less than two feet. The thinking here is that fish need a certain amount of depth to survive the winter (in temperate to mild-winter climates, of course) and to hide from predators. Chris Preston, another California contractor, says that he?EUR??,,????'???s seen pond of 18 inches or less lose fish to birds and raccoons. He recommends a depth of three feet or more for ponds in vulnerable areas. McMahon, however, recommends that no pond be deeper than 18 inches?EUR??,,????'??+to comply with local codes that can require swimming pool permits for anything deeper than 18 inches.

This stream includes a small pool but lacks a pond-like water feature. This job uses smaller stones and makes an easier-to-build project than a true pond. The iris flowers near the top of the structure also grow in terrestrial gardens.

Contractors should also remember that any pond installed in an environment with small children should be enclosed by a fence.

The digging sequence is also important. Each big pool in a pond structure should have two depths?EUR??,,????'??+a shelf level and the deeper part of the pool. Workers should first dig the entire pond to the shelf level before carefully proceeding on the deeper part.

It?EUR??,,????'???s very important to stay aware of the finished water level during construction so the depth will be correct. A laser leveling device can be useful for making sure the berms enclosing the pond are close to the same height. The pond?EUR??,,????'???s final water level should be about two inches below the top of the berm. Some variation can be an asset, however. ?EUR??,,????'??It doesn?EUR??,,????'???t have to be perfectly level,?EUR??,,????'?? McMahon says. ?EUR??,,????'??Some difference gives it character.?EUR??,,????'??

Once the shape is roughed out, it?EUR??,,????'???s time to create a waterproof barrier between the new reservoir and the ground. The barrier itself is a 45-millimeter rubber liner. To protect the liner, pond builders place a felt-like underlayer of geotextile material on top of the ground, with the liner sitting on the protective layer.

?EUR??,,????'??Rocking-in?EUR??,,????'??

The project now enters a critical (and from the contractor?EUR??,,????'???s point of view, fun) portion?EUR??,,????'??+the phase sometimes referred to as the ?EUR??,,????'??rocking in.?EUR??,,????'?? A combination of gravel, stones and boulders is the key to making the pond appear natural. It?EUR??,,????'???s also a phase which gives the contractor a chance to make a creative contribution.

Choosing and placing the larger boulders can be a demanding physical task. These ?EUR??,,????'??accent rocks?EUR??,,????'?? can weigh 200 or 300 pounds or more and require several strong individuals and a specialized piece of equipment called a rock cart to move.

The rocking-in portion of a project should always be started in the center of a pool and piled outwards towards the edges to evenly load the liner.

Most projects will use two grades of fill gravel?EUR??,,????'??+one with stones between 3/8 and 1/2 inch and another grade between one and three inches. When the bottom portion of the pond is finished the crew can start creating the ?EUR??,,????'??steps?EUR??,,????'?? that will make up the cascade or waterfall. At this point, workers need to use an expanding foam product, sometimes called ?EUR??,,????'??waterfall foam,?EUR??,,????'?? to fill in spaces where water would normally squeeze through rocks instead of flowing over them.

?EUR??,,????'??You need to foam in rocks to direct water where you want it to go,?EUR??,,????'?? McMahon said. ?EUR??,,????'??You want most water to go over rocks. If you skipped this step most water would flow under them.?EUR??,,????'??

The crew is now ready to attach the pond liner to the waterfall tank?EUR??,,????'??+the buried reservoir that also contains the filter and pump hardware. The liner is securely attached using silicone sealant with a plastic lip screwed on to hold the connection in place.

Now that gravel and rocks are in place, it is safe to carefully trim the liner approximately eight inches to a foot from the pond?EUR??,,????'???s berm. The exposed portion of liner should be secured and hidden by soil and stones.

The pump at the Costa Mesa project is a 3,000-gallon an hour model with the capacity to completely turn over (and filter) the pond?EUR??,,????'???s approximately 800 gallons several times an hour.

One thing that can be hard to figure out is the total capacity of the pond?EUR??,,????'??+an essential number for calculating various treatments and additives. There are several reasonably-priced meters that attach to garden hoses and let contractors and homeowners precisely measure how much water it takes to fill the pond.

Water tumbles over the pond?EUR??,,????'???s main ?EUR??,,????'??fall.?EUR??,,????'?? Keeping fall height to a foot or less limits evaporation?EUR??,,????'??+and splash noise that can overwhelm property owners, especially at night. An expanding foam product is used to fill the space between rocks. Right: A PVC pipe is used to route flow from the bottom of this stream system. The cord feeds power to a pump that will send the water to the top for another circuit. The hardware here is exposed for demonstration purposes?EUR??,,????'??+it normally would be covered by stones and gravel.

Now it?EUR??,,????'???s time to add water. Many contractors prefer to do a ?EUR??,,????'??wash-down?EUR??,,????'?? or two to clean dust and debris from the pond. Chemicals added to tap water mean that fish will have to wait at least three days (the time it takes sunlight to break down chlorine products) or for the specified time it takes a chemical neutralizer to work.

Final Choices

Now the pond is full and filling the space around it with the tranquil sound of flowing water. It will take several more hours to choose and place a selection of aquatic plants that not only add a refreshing look to the pond but filter out debris
and bacteria while providing food for fish.

Patience is another element that the contractor and homeowner need to have after the pond?EUR??,,????'???s debut. Most ponds pass through an algae bloom that lasts from four to eight weeks in which algae growth outpaces the ability of plants and natural bacteria to keep it in check.

?EUR??,,????'??Especially at first, algae growth can just take off, and a lot of people freak out,?EUR??,,????'?? McMahon said. ?EUR??,,????'??But all ponds go through a green period.?EUR??,,????'??

After the green period, pond owners and maintenance workers will have to complete regular tasks like changing filters and adding beneficial bacteria to keep ponds clean and attractive. With a little attention, however, it?EUR??,,????'???s amazing how well the pond?EUR??,,????'???s micro-environment can function.

Treat the pond right and it will repay you with years of mostly carefree operation, explained Lloyd Mitchell III, an aquatic plant specialist at Pro Ponds West.

?EUR??,,????'??People call up and ask ?EUR??,,????'??Why isn?EUR??,,????'???t my pond balanced? I read the book and I?EUR??,,????'???m doing everything right.?EUR??,,????'???

?EUR??,,????'??You have to learn how to balance things out. Sometimes that means using more plants, for example, or feeding your fish a little less. You have to remember that the pond is a mini ecosystem.?EUR??,,????'??