Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student TJ Decker makes this connection here…

The two articles referenced under the WRE topic entitled, “Large-Scale Restoration Project Revitalizes River Herring Habitat” and “NATURE-LIKE FISHWAY INSTALLATION AT THE KENYON MILL DAM, PAWCATUCK RIVER, RHODE ISLAND” was reported by the NOAA National Marine Fisheries Service (NMFS) in September 2011 and again in the Association of Massachusetts Wetland Scientists (AMWS) Newsletter in 2013. The news relates to the WRE domain of hydrology and the specific issue of fish passageways and inundation flooding due to dam failure. In summary, the nature of the issue surrounds the constructed dams (circa late 19th, early 20th century) on the Pawcatuck River. In New England there are more than 25,000 of such dams and most are becoming antiquated, being previously used to supply water to old fabric and paper mills along the river shore. In order to prevent these dams from failing, resulting in significant flooding and to provide the ecological services that free flowing rivers offer, NOAA has begun restoration at dam sites all over the northeast. Since 1999, NOAA NMFS has been involved in at least 580 barrier removal projects with 88 of them dam removals in the region from Maine to Virginia. Based on my engineering education, my informed opinion is the WRE facts in the news are accurate as I show with the following research citations. In the text written by Wurbs and James, dam break analysis is described as a process that is often required in safety studies of major dams due to the possibility of the loss of life and property. Having this analysis is important for each of the dams on the Pawcatuck River so that the potential negative effects a dam can have upon the ecosystem are understood. A second main concern of small dam removal and analysis is the improvement of fish passage along a river. In Maine, the removal of a small dam built in the 1800’s allowed a decreasing population of sea lamprey to begin repopulating the area in which they used to inhabit (Hogg, 2013). The article written by Hogg proves the important nature of this NOAA NMFS centered work.  Based on critical thinking on this news story, I think the article has missed describing the difficulty of achieving success with these types of projects both economically and socially. The engineering solution can be provided with some calculations and design, but can organizations, communities, and the environment be ensured that the project will attain the desired results given the significant investment in dam removal?

Water resources engineering influences global, economic, environmental and societal context areas because it is an interdisciplinary topic that manages hydrologic and hydraulic systems at many scales to efficiently deliver services for many users. In the topic of restoration on the Pawcatuck River, the areas of economic, environmental, and societal issues are addressed. Related to economics, dam removal and fish passage will restore the spring run to near 500,000 river herring and 5,000 American Shad providing fishermen with a larger catch and income (Turek & Ferry, NATURE-LIKE FISHWAY INSTALLATION AT THE KENYON MILL DAM, PAWCATUCK RIVER, RHODE ISLAND, 2013). By increasing the availability of habitat and spawning area, dam removal and fish passage restore the environment and provide a more sustainable future. In terms of societal impacts, dam removal alleviates the risk and fear of dam failure and the resulting floods that could have catastrophic impacts. The broader context is that by designing new solutions to antiquated structures on the Pawcatuck River, nearby communities can become connected to the environment surrounding them and further understand the impact that human populations have upon the environment. Also, if human populations work together with the environment, each can have a greater benefit with fish being able to thrive and fishermen having a greater profit on a larger catch. Based on the two articles, the context area (Northeast) will benefit from the economic, environmental, and societal changes that improve the ecological situation of the Pawcatuck River. I found that in a similar article written by Gangloff, dam removal needs to be considered after the process of stream restoration prioritization. The prioritization gives details of long term assessment as well as positive and negative effects of small dam removal. Financial constraints often prevent this assessment from being completed and reduce the understanding of the long term impacts that a dam or dam removal can have on an ecosystem. The cause-effect between dam removal/fish passage and economic, societal, and environmental impact is as follows – fish passage will improve migration patterns and fish population, more fish equals a higher income for fishermen, a dam failure will directly lead to inundation flooding and loss of life and property, and a more natural free flowing stream will promote a healthier ecosystem.

Post-construction assessment of flows approximating normal fish-run condition

Post-construction assessment of flows approximating normal fish-run condition

October 2013 construction of the Kenyon Mill stone fishway weir and weir notch

October 2013 construction of the Kenyon Mill stone fishway weir and weir notch

Upper View of Kenyon Dam removal temporary bypass diversion channel & left riverbank

Upper View of Kenyon Dam removal temporary bypass diversion channel & left riverbank

Works Cited

Gangloff, M. M. (2013). Taxonomic and ecological tradeoffs associated with small dam removals. AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS, 475-480.

Hogg, R. (2013). Anadromous Sea Lampreys Recolonize a Maine Coastal River Tributary after Dam Removal. TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY, 1381-1394.

Turek, J., & Ferry, K. (2011). Large-Scale Restoration Project Revitalizes River Herring Habitat. NOAA Commerical Fisheries News Special Supplement , 4.

Turek, J., & Ferry, K. (2013). NATURE-LIKE FISHWAY INSTALLATION AT THE KENYON MILL DAM, PAWCATUCK RIVER, RHODE ISLAND. Association of Massachusetts Wetland Scientists Newsletter No.88, 10-14.

Wurbs, R. A., & James, W. P. (2002). Water Resources Engineerin. Upper Saddle River : Pearson Prentice Hall.

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