| 23F | Twenty Three Feet | |
| ACCST | Advanced Continuous Channel Shifting Technology | |
| ACE | Annual chance event, referring to the flood event with a specified chance of occurring in one year. E.g. the 1% ACE is the flood with a 1 in 100 chance of occurring in any one year. | |
| ACWI | Advisory Committee on Water Information | |
| ADF | Average Daily Flow | |
| AEP | Annual Exceedance Probability | |
| AIRCA | Association of International Research and Development Centers for Agriculture | |
| AML | Abandoned Mine Lands | |
| AOV | Air Operated Valve | |
| ARI | Average Recurrence Interval | |
| ASHU | American Spatial Hydrology Union | |
| AVRDC | Asian Vegetable Research and Development Center | |
| BAHM | Bay Area Hydrology Model | |
| BG | Black Gold | |
| BGL | Below Ground Level | |
| BPV | By-Pass Valve | |
| BV | Butterfly Valve | |
| CBAWO | Cape Bounty Arctic Watershed Observatory | |
| CEAH | Centre for Environmental Applied Hydrology | |
| CEH | Centre for Ecology Hydrology | |
| CEH | Centre for Ecology and Hydrology | |
| CHG | Certified Hydrogeologist | |
| CHY | Commission for Hydrology | |
| CIMH | Caribbean Institute for Meteorology Hydrology | |
| CIMH | Caribbean Institute for Meteorology and Hidrology | |
