An engineered assembly of drainage boards, perforated pipes, gravel beds, and sump pumps installed around the exterior or interior of a foundation. It captures groundwater and channels it away before it can build up pressure against the waterproofing membrane and the concrete walls. By removing the standing water, it prevents the severe structural loads and leak risks associated with deep water tables.
The basement walls are leaking because the hydrostatic pressure relief system clogged with silt and the water table rose.
Do not mix it up with
- Hydrostatic pressure: Hydrostatic pressure is the force exerted by standing water, while the relief system is the drainage network built to eliminate that force.
Related terms
Hydrostatic pressure
Pressure from standing groundwater against a wall or slab, rising with the depth of water above that point.
Drainage composite
A dimpled or ribbed plastic core with filter fabric that carries water down to drains instead of letting it sit on the membrane.
Sump
A built-in depression around a roof drain that accelerates water flow and prevents ponding.