Backwater Effect 2 : The rise in water surface elevation caused by some obstruction such as a narrow bridge opening, building or fill material that limits the area through which the water must flow
New Hampshire Floodplain Management Handbook (Appendix B), Glossary, New Hampshire Office of Energy and Planning, NH, USA 2006. http://www.nh.gov/oep/programs/floodplainmanagemen t/documents/NHFloodplainHandbook2006.pdf, (ND/ Flood - Amer) {169}