Welcome to Pond Boss!

Your goals for a pond right beside your house sound very nice.

I definitely would not like having a LEAKY pond right beside the house.

If it was my project, I would certainly consider installing a pond liner to get a 100% effective seal.

I believe quality pond liners currently run about $1/sq. ft. (If you buy it locally and avoid the shipping charge.) That would only be $900 for a 30'x30' pond.

If you want water plants, then I would create a few level shelves in the pond before placing the liner. You can then place dirt-filled black plastic pots on the shelves that do NOT stick up above your water elevation. You can then plant lilies, reeds, etc. in your pots and have nearly complete control over their location and spreading.

If you want lots of edge plants, then create two rims with your liner near the circumference of your pond. The narrow basin between the two rims can be filled with soil to support your plants. The inner rim should be just below your normal water elevation so the plants have water that can exchange with the main pond - but the soil cannot.

What I suggest above will certainly involve a fair bit of labor. However, it can all be performed by 1-2 able bodied adults for a pond and liner that small. There are also crews for hire that do those installations. (If you hire a crew, then you can also increase the depth since they will have earthmoving equipment. Or you can easily run a mini-excavator yourself. They are easy and safe to operate on level ground, even for a new operator.)

If you do NOT like the liner, or it is above your budget for the pond, then I would definitely try to perform a seal job on the existing pond.

Sealing jobs always have a chance for failure. However, a 3' deep pond has very little hydrostatic pressure trying to push the water out through the leak paths. If your conditions are moderately favorable, then it should not be that difficult to seal.

If you want to go that route, my best advice to you would be to contact our best leak expert (TJ). He can recommend if physical product additions might work, or if you need full-scale construction equipment repairs.

Here is a link to his profile: TJ Profile

You can contact him via Private Message through the forum, or through his email which is listed in the profile.

He may not respond rapidly, since he is probably catching up on family time during this part of the year. However, he graciously volunteers to give free advice either in the thread (for public viewing) or in a phone consultation.

He also sells a product called SeekLeak, which is frequently more efficient and/or cost effective than bentonite in sealing several types of leaks.

Good luck on your pond project!