After reading that title, you may be asking yourself, “What could these three things possibly have in common?” They all have to do with big mistakes in pond and water-feature construction.

I frequently have to tell pond owners, “They built you a Cadillac on a moped chassis.” I say that when I come across a waterscape that, like a Cadillac, looks great— until you plug it in. Then you find out that it won’t run, because it was built on too small of a foundation, one more appropriate for a moped.

I’ve seen far too many water features that have catastrophic design flaws. These are often gorgeous things, with fantastic rock and boulder placement. However, they leak like sieves, or are woefully underpowered, under-flowing and under-plumbed. They scream to me of overly ambitious, inexperienced pond builders, very possibly led astray by misinformation. This leads to disastrous results for the owners of these ponds.

Meanwhile, the contractors who built them simply quit returning calls. They go back to their landscape maintenance operations, or to selling rocks and mulch, determined not to get pulled into one of these money-losing water-feature projects again.

Size, leaks and rocks

Size really is important when you’re designing waterscapes. Yet, I don’t know how many articles I’ve read, written by prominent so-called ‘authorities’ in the pond industry, claiming that building large waterscapes is no different than building small ones. I beg to differ.

Leaky ponds often come from inadequately protected liners. You must always, always protect that liner! But many small pond builders don’t use, or have been advised not to use, underlayment in their streams and waterfalls. This advice is based on the theory that, in a small pond, there isn’t a great amount of water weight pushing down on the liner.

This is true, if all you have is the water in that small pond. However, when you’ve stacked up tons of boulders in that small pond in order to create a large waterfall, that theory goes out the window. You’ve added a lot of additional weight.

Underlayment and padding are musts in situations like this. If you intend to use rocks weighing more than 100 pounds in your stream area, I suggest using an underlayment similar to what you’d use in the pond area.

When you start getting into the 300-pound-and-over range, you should really consider using overlayment as well, made of the same type of fabric, directly under the larger rocks. Once you start going over 500 or 600 pounds, I strongly recommend additional padding. Based on your substrate, you may want to consider additional protection under the liner as well as above.

Closed-cell foam sheets can be cut to size to add additional liner protection in the places where contact with the boulders is expected. I often use multiple layers of foam, in two strips, to support larger boulders. It also helps leave a space for getting the straps out after the final positioning is done. Always leave extra liner to allow for settling and shifting.

As a professional pond consultant, I’ve seen lots of huge boulders that have caused improperly or inadequately compacted soil to shift and settle. This allows the liner, cut too short to begin with, to leak, often in multiple locations. Even if the liner wasn’t too short at the time the project was completed, it is now, after many tons of boulders have shifted and settled on it.

If extra liner was left over at the time of the original installation, and folded or rolled up along the edges rather than cut off, a fix will take just a few minutes. But if not.... That’s why I always leave at least a foot of liner, above and beyond what’s necessary, so there are no leaks.

For any water feature and its attendant equipment, compaction of the base soil is critical. When you’re using large and extra-large stones or boulders, it becomes even more critical. Anyone who has built an engineered retaining wall or a roadway knows the importance of base preparation and compaction. Well, it’s no different with large boulders.

Most water-feature equipment, whether heavy or light, is made of plastic. It just can’t stand up to the weight of massive rocks without bending and distorting. This will cause additional leaks, as well as make the feature difficult, if not impossible, to service. Most skimmers on the market can’t handle vigorous compaction of the soil around them at the time of installation without some distortion. Over time, the skimmers can become misshapen to the point of being useless.

How do you find leaks in these Cadillac/moped monstrosities? The truth is, there’s very little you can do. You can do systematic leak testing with an independent pipe from the source pump. But you can’t just roll an 1,800-pound boulder to the side and check the liner, as you could with a much smaller 180-pounder. Once you’ve determined where the leaks are, then hopefully you can tear out only a limited area of the feature for redo.

The same is true of water features that incorporate rocks that were mortared or cemented in place. There’s no way to move them aside to check for problems. Odds are, you’ll damage or destroy the liner in the process of breaking up the mortar or cement. Checkmate! You’ll just have to tear the whole thing out and redo the job—the right way this time.

Avoid building an ‘octopus’

Now I’ll explain what I mean by the term ‘octopus.’ It’s what I call a water feature with multiple skimmers and submersible pumps, spread all over the place. If all you sold were submersible pumps, I can see where you’d want to push this methodology.

But an octopus is a pain in the rear with regard to electrical consumption. A single, high-efficiency external pump can easily take the place of two or three submersibles. Relatively small satellite skimmers are available from several sources within the pond industry, negating the need for full-sized skimmers just to hold pumps.

If you use satellite skimmers, a manifold and an external pump, you can cut down on your initial costs, as well as long-term power consumption costs for the client. (By ‘manifold,’ I’m referring to multiple source lines coming into one communal line, to a pump’s intake. Each of these source lines should have their own valves, so that adjustments in system efficiency can be made.)

Many times, I’ve replaced multiple submersibles with one external pump, and cut electrical consumption by as much as 75 percent, with an actual increase in overall water flow.

This external pump technique really proved its worth when I used it to fix a pond created by some ‘rocket scientist.’ This person, who believes in the ‘bottom drain’ theory, put a pump in the bottom of the pond and buried it under a pile of rocks and gravel.

At first glance, this approach might make sense—to someone who doesn’t work on ponds. As an experienced pond professional, however, my first question was, “How do you service or replace the pump?” You can’t, unless you drain the entire pond.

That’s not what I’d call forward thinking methodology. What did this designer think was going to happen when he forced the pump to suck water through the rocks and gravel, covering up its intake? It’s a perfect setup for pump failure.

By using a manifold, you can adjust the amount of ‘pull’ you want from several sources, including a ‘bottom drain.’ And, with an externally-mounted pump, you won’t have to drain the entire pond just to get the carcass of a suicidal frog out of the impeller.

I will close with just one final question: Who protects the homeowners? We do—or we should, anyway. After all, we water feature builders, for the most part, live off our clients’ scarcer-than-ever ‘disposable’ incomes. It’s up to us, the professionals, to protect our clients from unneeded expenses or repairs.

We need to prove our worth on every single project in order to keep our businesses, and our industry, alive and thriving. Learning what to do, and what not to do, is our responsibility as professionals. I hope that what I’ve shared with you in this article will help you prove your worth to your clients.


EDITOR’S NOTE: Dave Jones is the owner of The Pond Professional