Cutoff Wall
Water
A wall of impervious material (e.g., concrete, asphaltic concrete, timber, steel sheet piling, or impervious grout curtain) located in the foundation beneath a dam and which forms a water barrier and reduces seepage under a dam or spillway.
A wall of impervious material (e.g., concrete, asphalt concrete, steel sheet, piling, etc.) built into the foundation to reduce the seep rate under the dam.
- — Dam Safety - Glossary of Terms retrieved 2014-06-01