City of Valdez
Valdez, Alaska
River Engineering, Floodplain and Sediment Management
City of Valdez
Valdez, Alaska
River Engineering, Floodplain and Sediment Management
The City of Valdez is built on the floodplains, deltas, and alluvial fans of three highly dynamic braided river systems that drain the surrounding rugged alpine terrain. Management of these rivers is complicated by high (and highly variable) sediment supply and hydrogeomorphic events including glacier outburst floods and debris flows. These create unstable river conditions including rapid lateral channel migration and sediment budget imbalances leading to rapid aggradation and degradation. NHC was contracted to help the City better manage these rivers by providing input into both local-scale engineering designs and river-scale management strategies. NHC conducted a systematic, geomorphic process-based investigation of each of these three rivers to provide the foundation for determining appropriate long-term strategies to manage channel migration, sedimentation, and bank protection infrastructure. In addition, NHC provided detailed specific guidance and review on bank protection and sediment management projects for immediate implementation.