Pond Boss Forums INTRO Questions & Observations Keyway question...

I've been told that it would be smart to put in a keyway around my pond (construction starts very soon).

Just what exactly is a keyway? How much would it add to the cost of a pond? Under what circumstances would be it worth the extra expense?

The keyway goes under the dam and is also called the core trench. If you are doing this yourself you need to do some research on here as a keyway would not only be smart, but not doing it could result in a leak at best and catastrophic failure at worst!

Thanks, Todd. I've got Bob Lusk as a consultant to protect me from my own gross ignorance, but you guys are very helpful as well.

anthropic,
To help with a visual, here is the core trench from my engineering drawings. I removed everything else as there was a little too much information to be plastering on the web. If you want the whole plan, send me a PM with your email and I will be happy to send it.

Core trench design

Have fun and get some sleep now b/c you won't when they start digging!!!

Thanks, Ben! Yeah, the closer it gets, the more excited & nervous I get...

PS I lived for many years in Beavercreek, Ohio, not far at all from Enon.

I grew up in Beavercreek, most of my family is still there. Small world.

That is not nearly enough info. Just enough in your first post to make things potentially confuzing. What type if pond are you having built?? Is it a dam or more of a duggout? How will the pond fill?? How big and deep? Then the fun qu es ions too like what fish are you considering.

Anthropic

You already have Lusk, you have access to Otto - congrats. You can't possibly be in better hands. Tell them what you want, outline a budget, set your goals. They will get you there as quickly as possible within your set fiscal parameters - guaranteed. Don't get me wrong, we love talking about core trenches here, but wanted to reiterate you made a great choice working with Bob and Mike and they both have written many books on these very topics.

Core trench important? If you have a dam, it's of paramount importance as it seals it. If you're digging a pit pond, surrounded by good clay, you won't have a core trench, but compaction of good clay soils becomes very important.

Who is building your pond?

what he said, but don't arm your self with miss information from am matters like ..... what I might say with out knowing all the facts or seeing the site to"argue" with a somewhat seasoned pond meister,hehe. Had a couple once that wouldn't stick trout in a lined pond they didn't want reproduction in but wanted some fish for dirt cheap and readily avaliable (trout is all there is in this area) because a "professional" said they would be a bad choice in a phone conversation.

Thanks for all the input, guys!

Mike Smelley, a local Marshall, TX pondbuilder and dirt mover, came highly recommended to me. Mike Otto helped me look over the property, mostly searching for clay. After Otto looked the first time, he said he wouldn't build a pond there -- too chancy. Fortunately he then got someone with a backhoe to come out and dig. Eventually we found good gray/white clay near the streambed in what will be the dam area, so I bought the property.

Smelley has built a couple of dozen ponds successfully. He also impressed me with his honesty about the soil necessary for a good dam. Otto told me that he had too much going on and was too far away for him to actually build the pond, but offered to answer questions as I go through the process. He's a good man, not just a good pondbuilder. I definitely want to hire him as a consultant for a day or two during the project to make sure everything is going well, though I think Smelley will do fine.

With Otto and Lusk as consultants, I feel a lot better about the whole thing! Nothing is ever guaranteed, but at least they will restrain my dumber ideas.

Re keyways, this was actually about trenching around the pond perimeter, rather than just the core section of the dam. I heard from someone with a leaky pond that they wished they'd done a keyway, so wanted to know if anybody had heard of it.

If you are building a pit pond, without a dam structure, packing clay in 6" lifts with sheepsfoot roller up to 24" will provide a good seal. Work it in along the sides and entire bottom of pond. Otto recommends this process he will direct your pond builder - who also may intend to employ this process already. IMO building a core trench around the entire pond is unnecessary if clay is packed in lifts - further that represents capital I would suggest directing towards other projects like vegetation establishment, stocking, fish feeders and food, docks, rock, trees, toys, etc.

Ask Mike and your builder what they think - I believe they'll likely agree core trenching a pit pond is unnecessary. Primarily used for dams/levees only.

Thanks, TJ. You are probably right, I'm already spending a good bit for the dam & other construction stuff. Sure seems like every time I turn around there's another idea I'd like to try, from Mossback fish attractors to Texas Hunter feeders to Biohaven Floating Islands to a growout pond for tilapia/prawns. They all cost money. Probably shouldn't go for keyways around non-dam areas unless there is a special issue somewhere.

I'm sorry I must have misunderstood - so you are building a dam, or is this a pit pond without a dam? I might have missed an earlier post of yours....if you are building a dam, absolutely install a core trench likely recommended by your builder. I would never suggest otherwise for a pond with a dam.

Both of those products look promising - I spent quite a bit of time hanging around the mossback display - sure seemed fishy to me. However, you can also source our collective forum ingenuity and a little creativity to achieve cheaper, or free alternatives, which are just as effective. Many designs exist in the structure archives for homemade PVC globes/trees, pallet condos, cedar pile clusters, etc. If you need suggestions, just holler. I built all my structure using scrap PVC from a local plumber - which was free.

I love your grow out pond idea - big fan of mini ponds - for forage, growout, recruitment, fishery experiments, etc. I have four of them and they're a blast, relatively cheap to build, and far easier to manage and maintain due to their size. If you screw up, like I do all the time, drain, seine, nuke and start over. If I had money left over after your primary pond build, I'd be thinking about where I could pop a couple forage/growout/experimental cells around the primary pond perimeter - and focus that capital there. But that's just my personal take.

I agree with your plan to get Mike involved as a consultant. He will never cut corners on a pond - if he thinks you would benefit from trenching your pond perimeter, go for it - I've just never read of anyone doing this - but that doesn't mean anything - I'm not a pond builder. There's probably not a pondmeister on the forum who didn't wish Otto was on site for our pond construction. Expert pond artist, and I agree - an even better person.

Lusk will create an appropriate stocking strategy and stand behind his work 100% - he's creative, thoughtful, and has 40 years experience as a leading pond management pro.

Man, I'm jealous. You're locked and loaded!