How to Build an Above Ground Pond With Cinder Blocks
The site you are considering for a pond plays a large role in determining the type of pond to build. Occasionally, ponds must be built above the ground, especially if your property has little soil or a lot of rock. Ponds constructed from cinder-blocks solve the digging dilemma. This classic round pond is easy to construct but can be more expensive than an underground model due to the number of rocks required. If you have an abundance of rocks on your property be sure to take advantage of them for this project.
Choose a location for the pond. The best location is one where the pond can be easily viewed from many spots on your property. Clear any debris from the site that may interfere with the pond construction.
Lay a piece of twine on the ground to mark a 12-by-6-foot kidney-shaped outline. Use a measuring tape for proper dimensions.
Spread a 2-inch layer of sand on the ground following the outline for the pond. The first layer of blocks will sit on this sand.
Arrange the first layer of cinder-blocks on top of the sand line with the inner top corners touching.
Check each block as your place it with a carpenters level. Add sand under the blocks until they are even.
Check that the entire first layer of blocks is even using a string and a line level. Check from three different points around the pond.
Position the second layer blocks on top of the first layer, staggering the joints. Check to be sure the blocks are level.
Line the inside of the pond using two pieces of roofing felt. The felt pieces should overlap inside the pond and overhang on the outside of the blocks.
Lay the EDPM rubber liner inside of the pond and overtop of the roofing felt. The liner should cover all of the inside and outside of the blocks with a generous overhang of at least 2 feet.
Fill the pond slowly until it is 3/4 of the way full. As the pond is filling, fix any creases that may occur in the liner by pulling on the liner edge.
Place two rows of flat stones directly on top of the liner and the cinder blocks all around the pond. Overhang these rocks above the water so that they cover all of the liner.
Shovel a generous amount of dirt on top of the pond liner. Stack round stones starting at the bottom of the liner and working around and up the pond sides. Use extra dirt where necessary to fill in gaps and find smaller stones to fit.
Landscape the pond area and provide shade for any aquatic life by planting ornamental grasses and other native plants around the outside.
Things You Will Need
- 25-inch tape measure
- 8-by-8-by-16-inch cinder blocks, 50
- 2-foot carpenters level
- Line level
- 15-pound roofing felt for underlayment
- Utility knife
- 18-by-10-foot sheet of 45 mil EPDM rubber liner
- Garden hose
- Medium flat stones to use on top layer
- Variety of round stones to stack around the pond