Dams & Floodplains

Led by experienced hydraulic engineers and certified floodplain managers (CFM’s) the AMT water resources team provides a wide range of services related to dams and floodplains to help manage community risks.

AMT has worked on more than 50 dams in recent years ranging in size from 13-feet to 139-feet tall and involving the full range of dam types, hazard classifications and state permit needs. Dam rehabilitation designs have included spillway repair and rehabilitation plans, spillway capacity upgrades, dam raising plans including vinyl sheet piling and other types of major improvements. Minor improvement plans have included Principal Spillway retrofits, Low Flow Drains and Siphons, Graded Filter Drains, Blanket Drains, and other work related to access, staging and long-term maintenance needs. Dam studies have included Dam Inspections, Probable Maximum Precipitation Studies, Dam Break and Spillway Capacity Studies using HEC-HMS, Dam Inundation Zone Mapping using HEC-RAS, Hazard Class Determinations, Emergency Action Plans and Tabletop Exercises.

AMT also works on floodplain studies for our projects using SWMM, HEC-RAS and other software programs to model and map floodplains and floodways. This includes preparing flood mitigation plans to help manage risks associated with extreme flood events and incorporating flood mitigation strategies into drainage improvement plans to create safer communities. Resulting floodplain models are often used for FEMA Letters of Map Revision (LOMR) and other map amendments, and to help local communities with floodplain management programs. AMT can also assist in evaluating those local programs against FEMA guidelines and for participation in the FEMA Community Rating System (CRS) for a reduction in flood insurance premiums.