How can I hide pond liner behind 4 foot waterfall drop?

Question

I am unfortunately a committed DIY'r. I got some help with large rocks but I have a few tall drops that I need to hide.

I have a guy who recommended that I stack cobble and hold it in place with concrete/morter?

Is this the best idea? And if so does anyone have pictures of something like that?

Answer 1

That is a very ambitious water project. I hope it's not your first because water has special challenges and I didn't get it right the first or second time I built a water feature.

Some tips:

• the edge is where you can get leaks and want secure footing. Put a stone inside the liner at the edge like this and top with a paving slab. Excuse my poor diagram

To deal with the vertical rise you need to make a dry stone wall. I don't recommend mortar as the alkaline component will affect the pH of the water. You will need fairly big pieces of stone so they won't move and so you can stagger them back into the wall. Where there are spaces you can back fill with gravel. Here is what I did

You can just see the liner at the bottom edge. It goes up behind the wall and is tucked under the stone.

I must caution you that building stone walls where there is water with this height of stone is normally done by professionals who have access to heavy lifting equipment like Bobcats and large heavy stones. You can get really nice pieces of stone that sold as steps with dimensions of 3 - 4' long and 18" deep. A few of those on the base of your water feature and anything on top will have a good stable base. However these steps weigh 400 to 600 lbs and need two people and some lifting equipment.

Your other alternative which is cheap and cheeky is to buy some black pond foam which can add as a filler and adhesive and thin slabs of cut slate. Make sure the vertical rise is fairly flat and stick the slabs to the liner. Over time the foam does not continue to stick if there is any movement in the stone so after using it block it in with other stones.