5th Avenue Dam

As you explore the Olentangy River around campus, you will more than likely happen upon the 5th Avenue dam.  Despite its somewhat serene appearance, this dam has been causing controversy since 2002 when activists began calling for its removal.  The dam directly affects how the Olentangy flows through campus, the quality of its water, and even the types of activities that can be done of the river.  As a result, Ohio State students gotta stand up for what we think is the right thing to do with this dam!  Here are some facts about the dam and the implications of its removal . . . get educated, visit the dam, and let us know what you think should happen!

Fast Facts about the dam:

- built in 1935 to supply cool water to an Ohio State power plant, but no longer has a function
- 8 ft by 470 ft
- largest low head dam on the Olentangy (there are 10 dams in all)
- area around the dam fails to meet EPA water quality standards (http://fifthavenuedam.net/)

Issues with the dam:
- lowhead dams are safety hazards for swimmers and boaters
- a stagnant pool of water forms behind the dam, which has negative impacts on water quality and wildlife - for example:
~ reduces river's ability to assimilate urban runoff and combined sewer overflow
~ higher temps and lower dissolved oxygen negatively affect fish and insects
- according to the EPA's "Total Daily Maximum Load" report, the dam is a direct cause of poor habitat and water quality in the dam pool and water surrounding it (http://brockwell422.wordpress.com/2010/03/10/debate-continues-over-removal-of-5th-ave-dam-due-to-its-negative-environmental-impact-422-final/)

reasons to keep the dam:
- it's expensive to remove
- removal will release all the sludge that's currently gathered behind it
- lower river level
- may cause negative effects on fishing: http://www.youtube.com/watch?v=a5a6abrLv6U&feature=email

dam removal proposal:

Army Corps of Engineer would lead the destruction of the dam, which would cost an estimated $1.82 million.  The City of Columbus is currently looking for a source of funding for the project.





We had an interview with Sarah Dean, a senior at OSU studying fisheries and wildlife.  In this interview I learned some the key wildlife management issues with low head dams.

Matt:  What does a low head dam such as the 5th Avenue Dam do to fish and wildlife populations?

Sarah:  A big problem is fragmentation of the habitat, also dams change the habitat structure.  It makes the system deeper more like a pool, it essentially restricts the rivers to fish that are tolerant to deep slow moving water.  

Matt:  How do dams impact the water quality?

Sarah:  Sediment are concentrated with toxins, and dams restrict the movement of sediments allowing for higher concentrations 

Matt:  Do dams change the species diversity, maybe the proportion of native to non-native species?

Sarah:  Many macro invertebrates need faster moving, well oxygenated water.  This disrupts some of the predator prey relationship, affecting the food web.  Essentially dams homogenize the river only allowing a few tolerant species to take over.  Many game fish do better in slow moving water such as lakes, they then  thrive in the waters held by dams.  Species that are less prized for recreation such as darters are not as able to survive in these slow moving deep waters.  Darter are key for ecosystem function regardless of what value sport fishermen place on them.