I am building a wetland filter using cinder blocks, built directly on flat ground. It must be raised, to protect it from regular flooding.
I'm concerned if the construction is strong enough to support the weight of the water and rocks. Here are the details of constructions:
- The cinder blocks measure 16"x8"x8", will be stacked 3 blocks high (24"), and reinforced with 4' rebar driven into the ground.
- The entire structure measures ~7' wide by ~33' long.
- Then the holes in the cinder blocks will be filled with Quikrete Conrete Mix, mixed with 50% gravel.
- The blocks will be glued using Quikrete Maxon Mix.
- For added strength, a neighbor suggested I divide it into chambers. Will this help? That means added complexity to the plumbing, but is doable.
- Water is pumped from the pond bottom down a series of PVC pipes and splits, pumping the water equally to the bottom of each chamber.
- Chambers are filled with ~4 matrix blocks, covered in larger rocks, then a layer of gravel, and finally a layer of pea gravel. So they must support a great deal of weight!
- Each chamber is lined with a 45 mil 15x15' EPDM pond liner.
- In theory, the water should be forced upwards through the matrix blocks, layers of rocks, to the surface. The entire structure is set on a minor include, of about 5" per 25', so I think the water is forced upwards, then will flow from the highest chamber, down the lowest. The water then returns to the pond via a pipe or chute.
Does this construction seem strong enough to support the weight of the water and rocks, plus potential freezing during the winter?