The last vestiges of the dam-building era continue. But the era of the dam removers is well under way, as communities try to improve river habitat, restore fish migrations, or remove hazardous dams that are crumbling or no longer serve a useful purpose (though dam removal can also have potentially adverse consequences, such as the release of toxic sediments, or reductions in species that had adapted to the dam environment).
In 2008, about 60 dams were removed, according to the advocacy group American Rivers. That adds substantially to the more than 300 dams that have been removed since 1999, and about 790 dams removed in the last 100 years, according to the group's tally.
For a brief synopsis on each of the dams removed from 1999 to 2007, see:
Removal of dams in 2009 is hard to pin down, since final decisions often aren't made until a month or two in advance. As a starting point, though, American Rivers' Serena McClain (202-347-7550, ext 3004) says the following dams are likely among those on the list:
- MI: Thompson Dam, Thompson Creek; Nashville Dam, Thornapple River; Cascade Dam and Wolcott Dam, North Branch of the Clinton River
- NC: Steeles Mill Dam, Hitchcock Creek (potential for this to be pushed to winter 2009)
- NH: Maxwell Pond Dam, Black Brook (potential for this to be pushed to winter 2009)
- OR: Savage Rapids Dam, Rogue River
- PA: Darby Creek Restoration (multiple barriers); Mann Dams (2), West Branch of the Little Conestoga; Saucon Park Dam, Saucon Creek (tributary to the Lehigh River); Smethport Dam, Blacksmith Run; West Branch Chester Creek (2 dams)
- VA: Lake Charles Dam, Kimages Creek
- WA: Satus Dam, Satus Creek (tributary to the Yakima River)
- WI: Namahbin Roller Mill Dam, Bark River
Another source of information on dam removals is NOAA's Open Rivers Initiative, begun in 2005 (though other NOAA programs have aided in dam and barrier removals since 1996). The ORI program helps fund and provide guidance on dam and barrier removals in selected states whose waterways are closer to oceans or the Great Lakes, and home to diadromous fish. ORI has aided 60 projects with $6.8 million in funding in its two previous funding cycles (selected from 99 applications asking for $29.4 million).
The application process for FY 2009 projects closed Oct. 31, 2008, and spokeswoman Monica Allen (301-713-2370) says 39 applications have been received, requesting $12.5 million (though only $7 million is available). Funded projects generally must be widely supported by a community and the dam owner.
ORI also participates in joint funding efforts with American Rivers. The latest application period for these grants, which tend to be much smaller, ends Dec. 3, 2008. For more information, see:
None of the NOAA-funded projects have been fully assessed for environmental impacts following dam or barrier removal, Allen says, though some monitoring is under way, and more comprehensive monitoring is expected to be part of projects funded from now on.
For insights by others on post-removal impacts, see:
- 10 Dam Removals, 10 Years Later, September 2008, from the bookstore of the Association of State Dam Safety Officials (other potentially informative publications related to ASDSO can be found here, using the search word "removal" (without quotation marks), or other words of your choice). For a copy of any ASDSO publication, contact Sarah McCubbin-Cain, 859-257-2102.
- "Ecology of Dam Removal," by Angela T. Bednarek, February 2002.
- Hundreds of Google results, using search words of "analysis after dam removal".
The total number of dams removed in the US is becoming substantial. However, the removals are just a fraction of the more than 2.5 million dams and other barriers that NOAA says exist.
Of these, about 79,000 dams — the vast majority of which are regulated by state governments — are larger structures that are tracked by the Army Corps of Engineers. Nearly 12,000 dams are classified as posing a high hazard, and more than 3,300 dams have deficiencies that leave them susceptible to failure. However, the Corps has refused in recent years to provide access to its National Inventory of Dams, which used to be readily available on the Internet.
Four large dams that are becoming well known may be a little closer to vanishing. They are located on the Klamath River that flows through Oregon and California. A nonbinding agreement, which has many escape clauses that could negate it, could set the stage for removal of the dams beginning in 2020. The agreement participants include the US Department of Interior, the utility PacifiCorp, and the governors of Oregon and California.
- "Deal Paves Way for Dams' Removal on Western River," Associated Press, Nov. 13, 2008.
The nation's dams are increasingly well past their "expiration date." NOAA estimates that about 85% of all dams will be more than 50 years old — the average life expectancy of a dam — by 2020.
For more information:
- "Dam Removal Toolkit: Exploring Dam Removal: A Decision-Making Guide," published in 2002 by American Rivers.
- Association of State Dam Safety Officials, Sarah McCubbin-Cain, 859-257-2102; Dam Safety 101.
- TipSheet of Oct. 16, 2002.