Editing Columbia Basin Project (section)

==Environmental impact==
One environmental impact has been the reduction in native fish stocks above the dams. The majority of fish in the Columbia basin are migratory fish like salmon, sturgeon and steelhead. These migratory fish are often harmed or unable to pass through the narrow passages and turbines at dams. In addition to the physical barriers the dams pose, the slowing speed and altered course of the river raises temperatures, alters oxygen content, and changes river bed conditions. These altered conditions can stress and potentially kill both migratory and local non-migratory organisms in the river. The decimation of these migratory fish stocks above Grand Coulee Dam would not allow the former fishing lifestyle of [[Native Americans in the United States|Native Americans]] of the area, who once depended on the salmon for a way of life.

The environmental impacts of the Columbia Basin Project have made it a contentious and often politicized issue. A common argument for not implementing environmental safeguards at dam sites is that post-construction modifications would likely have to be significant. Tour guides at the Grand Coulee dam site, for example, indicate that a "fish ladder might have to be {{convert|5|mi|km}} long to get the fish up the {{convert|550|ft|m}} needed, and many fish would die before reaching the upper end" thus no fish ladders were built. Advocates of remedial measures point out that such steps would still be better than the status quo, which has led to marked die-offs and the likely extinction<ref>NWFS 2003 Update Summary, p.5</ref> of several types of salmon.

There are a number of issues regarding the runoff of irrigation water. The project region receives about 6 to {{convert|10|in|mm}} of annual rainfall, while the application of irrigation water amounts to an equivalent 40 to {{convert|50|in|mm}}. The original plans did not sufficiently address the inevitable seepage and runoff.<ref name=75years/> In some cases the results are beneficial. For example, numerous new lakes provide recreation opportunities and habitat for fish and game. In other cases [[agrochemical|agricultural chemicals]] in the runoff cause pollution.{{citation needed|date=June 2016}}