The Complex Decisionmaking Process forRemoving Dams

The evolution of gravel bed channels after dam removal: Case study of the Anaconda and Union City Dam removals

“…Numerous dams, most fairly small, have been removed (American Rivers et al, 1999) and monitoring is beginning to provide direct information on the mobilization of impounded sediment deposits, the direction and rate of upstream channel development, and the downstream impacts. However, the physical processes are difficult to predict (Pizzuto, 2002;Baish et al, 2002). This case study documents the behavior of impounded sediments and channel evolution at two low dam removals on a steep coarse bed material river.…”

Status and trends of dam removal research in the United States

“…Deciding whether to remove aging dams and how to do so with minimal adverse impacts, however, is complicated by uncertainties associated with potential environmental benefits and detriments . On one hand, dam removal can re‐establish more natural flows, water temperatures, and sediment regimes, and allow native organisms to recolonize habitats that were formerly inaccessible .…”

“…Deciding whether to remove aging dams and how to do so with minimal adverse impacts, however, is complicated by uncertainties associated with potential environmental benefits and detriments. [9][10][11][12] On one hand, dam removal can re-establish more natural flows, water temperatures, and sediment regimes, 10,[13][14][15] and allow native organisms to recolonize habitats that were formerly inaccessible. [16][17][18] On the other hand, removing dams can expose and mobilize large volumes of sediment and contaminants, [19][20][21][22] and facilitate the spread of invasive species.…”

Decommissioning, discontinuation and abandonment of dams: is there a case for a national strategy?

“…"When understanding of environmental systems is lacking, scientific consensus, and thus policy, will often be years to decades away." (Doyle et al, 2002) "Monitoring the site after the dam is removed is essential" and "ideally post removal monitoring should be included in the dam-removal budget (Baish et al, 2002). The aim is to develop dam removal as a science.…”