Description & Overview
Lowhead Dams are “deceptively dangerous” in both populated areas where they can cause death for human beings as well as disrupting the ecological balance in waterways and rivers where they have been built. “Ohio has an abundance of these killers on rivers throughout the state. Over the years, houseboats, fishing vessels, powerboats, sailboats, PWC, and canoes have all fallen victim to lowhead dams.” In Recent years, two brothers died after being caught in the powerful churn of the Dodridge Street dam in Columbus. Advocates for public safety and wildlife want these dams removed. The dam removal projects are expensive and complicated. In today’s economic climate it is difficult for any city, state or the federal government to allocate the money needed to remove the dams and to restore the riverways concerned.
Figure 1 : Water Flow Logistics in a Low-Head dam (
Lowhead dams can range from a 25-foot drop-off to a mere six-inch drop-off. Some dams are very wide and others not wide at all. Importantly though, how water moves through lowhead dams are the same regardless of the size of the dam. Most people associate danger with a dam having a significant drop off and fast-flowing water. However, people do not realize that the danger is just as catastrophic with a two- or three-foot dam face and a moderate flow of water.
Figure 2 : Mockup of waterflow that affect people falling tinto a lwhead dam watershed make it almost impossible to escape the lowhead dam hydrolics.
Danger is present both above and below a lowhead dam. Water flowing over a drop forms a hole or hydraulic chrning at the base that trap objects washing over the drop. The backwash or recirculating current is formed below the dam. Once swept over the dam, a victim becomes trapped and is forced underwater, pushed away from the dam, then circulated to the top. The circulating motion then repeats the cycle over and over again as the individual is drawn back against the base of the dam. Low head or run-of-river dams, are then a real safety hazard to people because they have “dangerous recirculating currents, large hydraulic forces, and other hazardous conditions sufficient to trap and drown victims immediately downstream from the overflowing water” as discussed above. Riverways are now increasing public recreational areas. So, large “numbers of kayakers, canoers, rafters, boaters, anglers, and swimmers are often unaware of, or underestimate, the dangerous forces and currents that these dams or similar hydraulic structures can produce if there are no warning signs, restricted area postings, boat barriers or bypass portages”. Statistics from ohio indicate more than 21 or more deaths occurr per year because of dams, five states have these kind of fatality rates, Ohio is one of the five states.
Many Low head dams have been constructed sine the 1800’s that are basically uncontrolled spillways. They were traditionally constructed across rivers and streams to raise water levels “for improving municipal and industrial water supplies, producing hydropower, feeding navigation canals, and diverting irrigation water”. “Tens of thousands were built in the 1800s to power gristmills and small industries”. At present , many have been abandoned and are dangerous to the public. Also the reasons for which the lowhead dams were constructed are redundant.
This project proposal concerns specifically the lowhead dams present in the Olintangy River system in the Delaware, Dublin and Columbus region of Ohio. The proposal will consider the history of issues associated with the lowhead dams. The writeup will also include the current status of the riverway from ecological, public safety, economic and political points of view.
Outline of project
I – Introduction
- Definition and description of Lowhead Dams.
- Lowhead dams in national context.
- Perspective on Lowhead dams specific to the Olintangy Riverway in Columbus, Ohio
II – Dams associated with the Olintangy Riverways
- 5th avenue lowhead Dam – Olintangy River
- Mainstreet dam – Scioto River
- Delaware County lowhead Dam removal
- Dams that have not been removed
- Existing Issues/Problems with remaining Dams in the Delaware/Columbus/Dublin Geographical area
III – Conclusions
IV – References
A fact sheet cataloging ecological and anthropological problems associated with low-head dams in Ohio, and citing specific reasons why they need to be removed. The fact sheet also catalogs public safety problems that can happen when the owhead dam is targeted for removal. sheet highlights many of the problems associated with lowhead dams and the benefits of dam removal.
- Navarro, John. “School of Environment and Natural Resources.” Benefits of Dam Removal on the Olentangy River | School of Environment and Natural Resources, Ohio State University, School of Environment & Natural Resources, 2017, senr.osu.edu/about-us/multimedia/benefits-dam-removal-olentangy-river.
Video delineating the problems with lowhead dams and what the benefit to the environment will be if these dams are removed. Discusses the efforts of the Ohio State University in this endeavor.
- Tschantz, Bruce A. “Low Head Dams.” Bruce A. Tschantz, P.E., Bruce A. Tschantz, Consulting Engineer, 2013, http://www.safedam.com/low-head-dams.html.
This website discusses the dangers of lowhead dams. Th website also provides national statistics and links to human deaths due to lowhead dams in the USA. Public safety regulations and needs are also discussed.
- Ringley, Byron, and Travis White. “5 Th Avenue Dam Removal & Lower Olentangy River Ecosystem Restoration Project.” ohiowea.org/docs/5th_Ave_OWEA_4-4-13.pdf.
Graphic presentation of project management of 5th Avenue Dam Removal & Lower
Olentangy River Ecosystem Restoration Project
- Ringley, Byron. “Unlocking a River’s Potential.” 5th Avenue Dam Removal & Olentangy River Restoration – Stantec, Stantec, 2014, http://www.stantec.com/our-work/projects/united-states-projects/-/5-avenue-dam-removal-olentangy-river-restoration.html#.Wcp4d4qQz5U.
Final project report on the completion of the 5th avenue lowhead dam removal and restoration of the riverway. This report includes the actual time line needed for project completion as well as the total cost associated with the entire project.
- Ferenchik, Mark. The Columbus. “Olentangy’s Low-Head Dams Deemed Too Costly to Remove.” The Columbus Dispatch, The Columbus Dispatch, 23 Apr. 2015, http://www.dispatch.com/article/20150423/news/304239755.
Report on the remaining dams on the Olintangy River in the Columbus, Ohio area. Includesprojected costs of project and political discussion of the project.
- GALLICK, THOMAS. ThisWeek Community. “Plan to Remove Dams Held Back No Longer.” ThisWeek Community News, ThisWeek Community News, 18 May 2015, http://www.thisweeknews.com/content/stories/delaware/news/2015/05/15/olentangy-river-plan-to-remove-dams-held-back-no-longer.html.
Report on Delaware County Dam removal projects.
Gibson, Russ. “Restoration Efforts Improve Aquatic Life in Olentangy River.” http://www.epa.gov/sites/production/files/2015-10/documents/oh_olentangy.pdf.
Report on the work completed through the Olentangy River Restoration Project, specifically in the city of Delaware, Ohio and in Delaware county. The article discusses original assessments used to target the four dams that were removed. The article also discusses environmental aspects and financial aspects of the dam removal over time from 1999 to the final assessment of approximately three miles of
the Olentangy River.
ohio lowhead dams