Pond Boss
Posted By: Dylanfrely Clay Lining and Trees - 08/30/21 04:37 PM
Tried searching the forum for an answer and found both yays and nays, so I'm hoping to get peoples thoughts on trees close to clay lined ponds.

I'm in the middle of digging out a ~ 1/2 acre pond which will end up being about 12-14 feet when done. I live in the low Sierra Nevadas and have a mix of oaks and pine on the property. I've removed some from the immediate area for the pond, but there are several nice, large trees that will be around 5 feet from the edge when completely full. My soil is "okay", with areas of solid clay and some of sandy loam. Because of this, I'm planning to line it with bentonite clay.

Would leaving the larger trees be high risk for roots getting into the pond and creating a leak? I don't mind a little extra plant material in the pond and want it to look natural with the landscape, so I'm hoping to keep the trees. If it's a huge risk, I'll go ahead and take them out.

Posted By: RStringer Re: Clay Lining and Trees - 08/30/21 05:02 PM
Will these trees be on the damn side or shallow side. I believe that they don't do much harm on the shallow side. The roots can cause problems on the damn side. Especially if and when they die. Im no expert on it but thats how I understand it.
Posted By: RAH Re: Clay Lining and Trees - 08/30/21 05:28 PM
If the tree roots would let water out of the pond (penetrate core of dam or a clay liner) if those roots died and formed a channel for water, then they present a future risk for a leak.
Posted By: FishinRod Re: Clay Lining and Trees - 08/30/21 06:01 PM

Yes, trees five feet from the clay liner are a risk. However, it is also how you want your pond to look. You are the one that gets to balance the risk versus the reward.

Are you going to be able to irrigate these trees?

If so, then I would give them lots of water AWAY from the pond during your Cali dry spells.

Have you ever fertilized the oaks?

You also might try fertilizing them (very carefully following the instructions) out to the drip line only in the 180 degree section away from the pond.

If your trees are perfectly happy without running roots through your liner, then they should be less likely to make the attempt.

Regardless, it is always nice to irrigate and fertilize your trees after they get a little abuse due to an earthmoving project.

Good luck on your pond!
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