Asked on Jul 08, 2012

Do concrete ponds normally hold water? Discovered in my backyard filled with dirt! Should I seal it w something?

by Jennifer
It is probably from the 30's - 50's and is currently filled with dirt. I am planning on digging it out, and getting it running by next year. It looks to be concrete with rocks along the top wall. It is only about 5' at the longest and 4' at the widest (roughly pear shaped), will that size be able to successfully sustain fish? (not counting fishing birds and wildlife ;) ) Thanks!! :)
  4 answers
  • Walter Reeves Walter Reeves on Jul 08, 2012
    You can experiment with concrete sealers but the easiest solution would be to line it with rubber or plastic pond liner
  • that is a rare find. Are you sure the cement was forming a pond? Or was there something else that could have been buried there? But a rubber liner would work fine or paint with water proofing paint if no cracks are seen.
  • Aquascape Inc. Aquascape Inc. on Jul 09, 2012
    Hi Jennifer! Concrete has been used to make ponds, but I wouldn't recommend it. Concrete cracks, and when it does, the pond will leak. Even if you put a liner over the concrete, you're still taking a risk. Groundwater can seep up from the bottom through the concrete where there's a crack, and then you'll have water between the concrete and the liner. This results in the trapped water pushing up on the liner and causing a whole host of problems for your pond. Your best bet is to remove the concrete and start fresh with underlayment and then an EPDM liner on top of that (the underlayment keeps rocks from tearing through the liner). It's best to do your pond the right way so that you'll spend more time enjoying your pond and less time maintaining it. The size you mention is fine for fish, just make sure the pond is at least 24" deep so they can hibernate at the bottom over the winter. You'll simply need to keep a hole in the ice during the winter season for exchange of gasses. If it helps, here's a link to a web page with photos showing a 20-step process for building a low-maintenance, ecosystem pond:
    • Joquita Sullivan Joquita Sullivan on Jan 24, 2021

      Wow, well that was a downer ! Thanks dude. You just destroyed a DIY projects on a diy website! LOL, good move !

  • Jennifer Jennifer on Sep 11, 2012
    I will post pictures soon. It's still filled with dirt... Thank you Aquascape for the info! :) I'm going to attempt to recycle/reuse first. Even if I have to have a 'plant pond' :) . I WILL have a water feature somewhere, though!! @ Woodbridge, geez, I hope I don't find anything scary....Pretty sure it was meant to be a pond, it's pear shaped, and has about a 5-6" thick concrete shell with rocks around the top. It's approx. 30" at the very smallest, and 4-5' at the thickest.