When we think of concrete, we typically think of something very durable that will last forever. And we’d like to believe that a concrete pond would follow suit. The foundations of our homes are concrete, after all! And our roads and bridges! And swimming pools! Yep, things that are expected to last forever are made of concrete. So, it just stands to reason that a pond should be made of concrete right? Meh, maybe not so much.
1. CONCRETE IS NOT FOREVER
Concrete is a rigid method of building. It’s exceedingly difficult (and often impossible) to add onto or enhance a concrete pond once completed. You also need to excavate it like a big bowl, which can be dangerous for pets, children, and wildlife if they fall in because it becomes very slick once the “pond patina” layer has formed.
Pools are made of concrete, this is true. However, underneath the concrete in pool construction are a bunch of things that help stabilize it and keep it rigid (like rebar), despite the movement of the earth around it. It's pretty expensive to put all that stuff in place, in case you haven't priced pools lately. If all you're going to do is dig a hole and slather concrete over it, you haven't done any of the things that make concrete durable enough to stand the test of time, like a pool. This process leads to failure of the concrete shell. Every time.
2. CONCRETE IS MORE EXPENSIVE
Once the ground has shifted or settled (which will definitely happen because the earth is always moving just a bit), you're looking at completely re-doing the whole thing in a few years because the concrete shell has cracked and now you have leaks. By the way, if you let that small leak go too long, it becomes a bigger leak, and the water leaking out may be undermining various structures around it via erosion.
You can try patching a leaky concrete bowl, but that’s not a permanent fix. A better “fix” would be to prep and coat it in a liquid rubber liner product, which is not cheap to do it properly. Oh, and it’s kinda ugly.
If you can’t fix it, you have to jackhammer out the old pond and put a new one in its place. And the whole process repeats. Remember the definition of insanity: doing the same thing over and over, but expecting different results.
3. A GOOD POND LINER CARRIES A 20-YEAR WARRANTY
Liner ponds allow the ground to shift around it without damage. Sure, sometimes there's a settling leak at the edge of a liner pond. But that's easy to fix: you just lift the liner a bit, shove some dirt under it, and call it bueno.
A good liner product (i.e., 45-mil EPDM rubber) carries a 20-year manufacturer’s warranty. Most concrete contractors don’t warranty their work beyond the 2-year requirement of the Registrar of Contractors. The one thing that concrete is guaranteed to do over time: crack. And leak.
4. FISH & PLANTS DON’T LIKE CONCRETE
Many a cement head has said: “Sure, Mrs. Customer, you can put plants and fish in the pond” right before they run out the door with that final check. And, yes, you can. That doesn’t mean that they’ll be happy. Concrete, filled with Portland cement, leaches lime and alkalis into the water forever, which does not make for especially happy, healthy plants and fish – especially considering our naturally high pH here in Arizona.
Because you can’t really build in plant pockets in a cement pond, you have to keep the aquatic plants in buckets. Not very attractive, and thinning/dividing those plants will be a bear some day. Then there’s having to fertilize the plants because you just can’t seem to teach those darn fish to back up the plant pots to poop – although, they do tend to dig in the pots like dogs. Fertilizer can then cause water quality issues.
5. A CONCRETE POND OR WATER FEATURE WILL NOT ADD TO THE VALUE OF YOUR HOME
Despite the claims, just because a water feature is built out of concrete, that fact alone will NOT add value to your home. What adds value is a beautiful well-built, serviceable water feature that fits well into its surroundings. It has nothing whatsoever to do with the construction method.
All that being said, if you plan to go spear fishing in your pond, or hand your kids a trident to play with, then you want to find yourself a good concrete pond contractor. However, if what you want is a well-built, serviceable pond system, you might want to continue your research on ALL of your options.