Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with societal, environmental, and other issues. Our student Ms. Williams makes this connection here…

The Land and Water March/April 2012 issue reported “An Urban Stream Restoration Case Study: The Northern Virginia Stream Bank” in its online news (also covered by Kentucky’s Sustain magazine). The water resources engineering issue reported on in this article is erosion and degradation of stream channels. This article specifically focuses on streams in the urban area of Reston, Virginia. The primary causes of urban stream erosion and degradation are greater volumes of stormwater runoff and higher flow rates. These causes are exacerbated in developed urban settings where higher percentages of impervious areas exist. The importance of case studies in stream restoration is that the modeling of erosion and sedimentation processes is still approximate at best and experimental given that it is based on field observations and not theoretical calculations (Wurbs and James, 2002). Therefore, successful case study stream restorations provide useful and important insight for future endeavors. The Wetland Studies and Solutions Inc. (WSSI) in Gainesville, Virginia, conducted this stream restoration and used regional curve data collected from a region in Maryland, which when applied an enlargement factor was deemed applicable to streams in the urban Reston area and thus created a tailored design curve specific to the Reston watershed area. WSSI used software called StreamDesigner to design the restored channels through an iterative process. I believe that this article accurately depicted the process of designing a restored stream using StreamDesigner software. However, WSSI has propriety ownership of this software and there is the possibility that different software, such as RIVERMorph, may have provided a more natural restoration design solution (Belcher and Athanasakes).

Image of stream bank degradation due to increased flow rates and volumes of runoff. Taken from www. epcamr.com

This article relates to the broader context area of environmental issues. Environmental issues deal with the relationship between human activities and the physical environment and the negative impacts on the environment that activities can have. For instance, soil erosion from stream banks results in decreased water quality and suspended sediments can also carry soil-absorbing polluting chemicals downstream. Environmental issues are integrally mixed with societal issues. Societal issues look at the relationships within a community that include both human to human interactions as well as human to environment interactions. The cause and effect between human impacts and this water resources issue is that further development of areas along with agricultural practices increases soil erosion and the degradation of stream banks. Figure 1 below illustrates the relationship between how increased development creates larger volumes of runoff from large storm events that the stream is unable to adequately handle. In addition, societal context includes the interaction between the people and their government. People rely on the government to implement policies and legislature that deal with water quality issues. These problems then relate to the broader context area of economic issues. Economic issues typically handle the distribution and expenditure of resources. Erosion has a negative impact on infrastructure and can thus result in expensive repairs leading to the need for stream channel restoration.

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