The era of dam building has left a legacy of structures that provide water and hydroelectric power and change downstream flooding. As the same time, the legacy includes infrastructure within our streams that has a limited lifespan as reservoirs inevitably fill with sediment and the structures succumb to the inexorable erosive power of water. Dams also result in damaged ecosystems; breaking connections that developed complex webs of interconnections over millennia. Removing dams is therefore inevitable both from a risk standpoint of having structures responsible for downstream safety that are past their lifespan and as a landscape level ecosystem restoration approach.
Dam removal requires the application of many elements that suit NSD’s core skill set of geomorphic analysis, risk identification, restoration design, and construction supervision. Dam removal will kick start fluvial geomorphic processes that have lain dormant for decades or centuries, so NSD provides geomorphic assessment of the downstream reaches to identify the trajectory and intensity of likely changes and implications for existing infrastructure. As part of restoration design and construction support, NSD provides flexible designs that can accommodate the changes and unavoidable surprises that will result from exposing and reawakening drowned land surfaces.