Adit 2 : A nearly horizontal underground excavation in an abutment having an opening in only one end. An opening in the face of a dam for access to galleries or operating chambers
National Dam Safety Program, U.S. Department of Homeland Security Federal Emergency Management Agency Interagency Committee on Dam Safety, Federal Guidelines For Dam Safety: Glossary of Terms For Dam Safety (FEMA-148), Washington DC, USA 2004. http://www.damsafety.org/media/Documents/PDF/fema- 148.pdf, (Dam Sfty - Amer) {890}