Feedback on My Basic Plan?

[JPaul]

Here's what I have done so far:

• Excavated the hole for the pond which is 10' x 6' x 2.5'. Can't really go any deeper as I am running into solid and massive rocks.
• Gently sloped the sides and removed all rocks and roots
• Screened all the dirt on the bottom with a 1/4" screen and tamped down

My planned next steps include:

• Putting some old carpet in the bottom. It is about 1/2" thick and 1/4" of that is a rubber backing
• Putting in a layer of sand left over from patio construction. Probably have enough for an inch along the entire bottom
• Putting in a 20' x 15' 45ml EPDM liner
• Digging a 8' x 2' x 1' bog across the highest end of the pond. It will eventually flow over some flat rocks with a drop of about a foot back into the pond

Any cautions, suggestions, thoughts on sequencing would be welcome.

 

[buckry]

That all sounds good to me, I don't see any red flags.

 

[ididntdoit99]

onyl red flag is the depth, but you didnt really say if you are putting fish in this pond, or if you plan on bringing them all inside for the winter. There is no way they would survive in 2.5 feet of water in our winters, im not sure about your climate.

 

[addy1]

We had a very cold winter after I built the our pond, we did freeze down 8 inches, I do have a lot of water. If the pond was smaller it might freeze deeper. I don't think 2.5 feet would freeze solid here. Notice I don't think lol.............not an expert.

My husband has a rental in pasadena md, it has a small preform in the front yard, maybe 18 inches deep maybe. When he bought the place, foreclosure, he move a piece of plywood found 4 fish in the pond. The place had been sitting empty over winter those fish made it. The plywood prob helped insulate it, but I don't know by how much it helped.

 

[buckry]

I have an 18" preform with goldfish, they over wintered fine in Indiana. Water froze to 7" they are are super healthy and as far as I can tell happy. They don't smile much, so not sure.

 

[Waterbug]

Since you screened the dirt and tamped it down and are using 45 mil EPDM I probably wouldn't bother with underlayment at all. It's so shallow I'd hate to lose more.

I'd think about a concrete block collar to get a little bit more depth.

 

[don't ask]

welcome JPaul...and i agree with waterbug

 

[JPaul]

Waterbug

Thanks. Would I just take the liner up over the concrete block collar? Any need to cushion the blocks before doing so?

 

[JohnHuff]

I'm in WA and in the winter I've never seen the pond freeze more than 2 inches here. My pond is only about 2.5ft deep and my fish have wintered through 10 winters. It's amazing that a pond can freeze 2.5ft deep!

 

[JPaul]

Is freezing the major downside to the shallowness, or is there something else that I need to worry about? Probably will be thinking about housing a few fish, but not koi.

 

[JohnHuff]

It's the freezing.

 

[buckry]

It's all about gases. When the pond freezes solid, no liquid water is exposed to the air. The water needs to release carbon dioxide and reabsorb a small amount of oxygen. Otherwise the fish suffocate under the ice. All you need is a single point of liquid water to allow for these gases to exchange, so a stock heater will keep a nice 15" hole in the ice for you. I did this last year, it was very straightforward.

The only other downside to shallowness is predators. 18" is shallow enough many animals get just step right in take what they want, ie fishes, and walk away fat and happy. I have 2 big dogs out 24/7 so that seems to help, but I am missing 1 koi, and at least a couple goldfish. No corpses, has to be predators. Dogs apparently take coffee breaks from time to time. Your 2.5 feet may discourage some, racoons maybe, but heron will have no troule standing in that water eating up your fish.

Otherwise, my goldfish are thriving in the 18" pond, so 2.5 feet should be world's better.

 

[j.w]

Buck I guess your goldfish must not be bothered by the heat in the 18" pond when the temps go way up eh?

 

[buckry]

The pond gets sun only from about 11am until 2pm, tons of shade, it's a problem in the fall, but so far this season it's been a dream. The water feels like it's 68 or 69 degrees. It never feels warm, always quite cool, and it's been 95+ here for 2 weeks. I also don't have my lilies really up to par in this pond yet either, so once they're cover the center like I intend it might even be cooler.

 

[Waterbug]

Would I just take the liner up over the concrete block collar? Any need to cushion the blocks before doing so?

You can lay something over the block if you like. But not really needed because there's not any pressure on the liner going over the top. And it's above the water line.

Is freezing the major downside to the shallowness, or is there something else that I need to worry about? Probably will be thinking about housing a few fish, but not koi.

There is a general feeling that more water volume reduces all kinds of problems. It's true to a point. But a well kept small pond is going to have a fewer problems than a poorly kept large pond. So really the bottom line is how the pond is kept, not size. But on the other hand most water gardens aren't really very well kept. Most people don't even know water can be tested.

Probably the most popular 500+ gal pond in the US, Aquascape, is 2' or less deep. Many keep Koi. In most pond forums these ponds are not well thought of, but there are still thousands of these ponds across the US being kept without any more problems than other types as far as I can tell.