How To Build A Below Ground Pond

Step 1: Choose Your Location

First, choose the location for your pond and place a stake in the center. Using a tape measure, mark 41 in. (1.04 m) on the string starting at the stake. Using paint and the string, mark a circle around the stake at the location of the pond.

Temporarily place the AB York blocks along the inside of the circle marked on the ground. Each course of the pond will use 27 blocks to complete the circle. Adjust blocks as needed, making sure the blocks are tight together. Use a shovel to cut around the blocks and mark where the sod and soil will be removed.

Step 2: Excavate

Remove the blocks used to mark the pond location. Next clear any existing landscaping in the entire area and dig a hole a minimum of 12 in. (300 mm) deep to accommodate the pond. Later, we will be using some of the removed material as backfill to add a gradual slope up to the pond’s edge.

Step 3: Create the Leveling Pad

Next in the bottom of the hole, dig a leveling trench 8 in. wide (200 mm) by 3 in. deep (75 mm) around the outside of the pond where the blocks will be placed.

If there will be a statue or fountain in the pond, dig a leveling trench for its location as well. Fill the leveling trench(s) with 3 in. (75 mm) of course sand. Compact the bottom of the pond and the sand leveling pad with a hand tamper.

Use a level and a straight 2×4 to level the entire pond area from side to side. A level base will make it easy to install the rest of the pond. If electricity is required for a fountain, please follow local electrical codes.

Step 4: Layout the First Course

Temporarily place the first two courses of AB York blocks on the sand leveling pad. Building the first two courses at the same time ensures proper alignment. Level and adjust each block from side to side and front to back. Once the first two courses are in place. Use a level and a straight 2×4 to level the blocks from side to side across the pond.

Step 5: Add the Pond Liner

Before adding the liner, carefully remove all the AB York blocks. The blocks must be leveled before the liner is installed to prevent damage to the liner later. When installing the flexible liner, be sure to press the sides of the liner into the outside edges of the pond. Be careful not to step or stand on the sand leveling pad.

Step 6: Install the Blocks

With the liner in place, carefully replace the first 2 courses of blocks in the location of the leveling pad. To avoid damaging the liner later, make only minor adjustments if possible to re-level the blocks. With the first 2 courses complete and leveled, install the 3rd course.

Step 7: Trim Pond Liner to Size

With the 3 courses installed, fold the liner up over the top of the blocks. Using onsite soils, backfill around the outer edge of the liner up to the top of the blocks. Gently compact this soil to prevent settling of the soil later. Using a utility knife, trim the excess liner at the outer edge of the top of this 3rd course of blocks. Remember that the high water mark can not exceed the top of the cut of the liner. For deeper water levels, you must bury more courses.

Step 8: Install Final Course of Blocks

Install the last course of blocks. If the pond needs electricity, chip off the bottom edge of one block using a hammer and chisel to make room for the power cord. Follow individual manufacturer’s instructions on proper installation of any accessory you will be adding to the pond.

Step 9: Finish With Wall Caps

Finish the pond with Wall Caps. They can be secured in place with concrete adhesive (optional).

Step 10: The Final Touches

Its time to add the water, decorative rock, a sculpture/fountain or plantings. When using rock, we recommend rinsing the rock before placing in the pond for best results. Finish the landscaping around the pond with mulch and plantings and enjoy.

Materials Needed:

• 108 AB York Blocks
• 27 Wall Caps
• 2 Tubes of Masonry Adhesive
• 6 – 50 lbs (23kg) Bags of Decorative Rock
• 1 Flexible Pond Liner – Minimum of 11 ft2 (1 m2)
• 600 lbs (270 kg) Sand