Ground Water - New Fish Pond - Hunstville, AL

[MajorDan]

Building a new pond and hit ground water at 12". The pond is an aquascape medium pond kit (8X11). The pond water level will be about a foot above ground level. A water fall and bog is planned all above ground level using additional underlayment and pond liner.

When raining, the amount of water entering the hole from this layer is significant, after rains some seepage continues. The ground here is clay and the layer that is leaking water is a rock clay layer. Planning on putting a french drain under pond.

I am thinking that the water pressure in the pond will lift any water that resides under the pond up to ground level and out of a 2" drain pipe. Considering a sump pump but thinking it may not be necessary. I am using a transfer pump now to remove the water so I can complete the dig and for when I start to put the underlayment and liner down. Plan to use a hose down the french drain outlet to remove any water that accumulates while I put the underlayment and liner in and start adding rocks.

Would appreciate suggestions/solutions from anyone with experience with ground water issues.

 

[Lisak1]

I have no suggestions, just a friendly welcome to the GPF! Lots of smart people here - someone will come along with some experience and suggestions!

 

[sissy]

welcome and only way you may be able to resolve that is put in a drain field and pipe for the water to run to it from under the pond .Not easy to do or cheap so you may be forced to build the whole pond mostly above ground .Is this a low area or high area on your property Meaning does water from your house or gutters run to this area .I know on my property I put pipes underground from my gutters to a dry pit that absorbs some of the water and the rest goes into underground tanks to be used to water the yard and plants

 

[Mmathis]

@MajorDan Hello and welcome. I am in the NW corner of LA. We have a high water table, and......clay. We rented an excavator to dig our 3000 gallon pond. We hit ground water at about 18”. Yep, it was fun watching the water seep out along the newly excavated pond walls! The pond did OK for its first year, but then we started having problems with collapsed walls and “water hippos” (where the water collects under the limer and pushes it up). Ended up re-excavating, and this time around we built a “collar” around the pond (concrete blocks, rebar, poured concrete), and raised the pond edge so that the top of the edge is about 12” above ground. It’s been 4 (or 5) years and so far no more problems.

Not my image, but this is basically what we did.

 

[MajorDan]

Thanks all for the welcome and suggestions. I am going to let the hole sit for a few days to see if it fills back in since I pumped it dry. My yard is essentially flat but I did run all of the drain spouts out to a swale at the edge of my property so that water is not part of my problem. I will have the water level at least a foot above ground level, but for now I am still in the not sure which way to go mode as I have a lot more digging to go and things my change a lot as I remove the rest of the dirt. I am planning on the bottom to be at 24" below ground level with no plant shelves. With plants in the bog filter there will hopefully not be many nutrients in the pond for plants to thrive. So after I raise the edges with blocks, the water will be 36" deep for most of the pond. Hoping no Hurricans come to visit until I get the pond finished.

New question:

Is the overflow in the skimmer, 2" pipe, sufficient to handle a Hurricans style downpour? Or do I need a 4" overflow somewhere in the pond in addition to that overflow?

Thanks all.

Dan

 

[sissy]

that is like what I did turtle mommy ,but I did 3 blocks up with 2 layers of cap block ontop of it .I would go with more than 1 overflow .I just left a gap in my top block and use a yard drain thing from lowes to keep fish from being washed out .I did have to modify it a little .

 

[Lisak1]

with no plant shelves. With plants in the bog filter there will hopefully not be many nutrients in the pond for plants to thrive

You may want to rethink that "no shelves" idea - we've had so many people post questions about how to add shelves after the fact, or how to add plants to the pond when they didn't add shelves. You can NEVER have too many plants in a pond. Just a suggestion from someone who should mind her own business! haha!

 

[Mmathis]

You may want to rethink that "no shelves" idea - we've had so many people post questions about how to add shelves after the fact, or how to add plants to the pond when they didn't add shelves. You can NEVER have too many plants in a pond. Just a suggestion from someone who should mind her own business! haha!

Excellent point! With my pond, the shelves are more about camouflage and making the pond look more natural, but are also fairly heavily planted. I just didn’t want straight sides.

 

[MajorDan]

No plant shelves planned. Predators every where. Neighbors cats are wild things.