You may have a retention tank in your building project to help reduce overload on your local stormwater system and also to gain LEED points. As these tanks are below grade, after construction it is very difficult and expensive to go back and do repairs, or to reapply coatings and membranes. Potable water tanks are often above ground and more accessible, but they are large and expensive to repair. Hycrete waterproofing solutions can help you in a number of ways. The waterproofing is inside the concrete � it is protected by the concrete.