Author(s): Ian Michael Hough; James Shucksmith; Phil Warren
Linked Author(s): James Shucksmith
Keywords: No Keywords
Abstract: Riverine ecosystems have adapted over time to the fluctuations inherent in natural flow. However, many rivers have undergone significant flow modification in order to provide services such as water supply and hydropower. There is a growing consensus among researchers that typical modified flow regimes do not sufficiently cater to the needs of downstream ecosystems. The impact of river flow modification and impoundment upon ecology is still poorly understood, however. Further conceptual and methodological advancement is required before environmental flow assessment and the prescription of more ecologically beneficial flows may become regular practice [1], [2]. This work will provide a novel framework to advance conceptual understanding of flow/ecology relationships and to provide practical output in the form of a recommended flow regime for a case study site. Such a regime must strike a balance between retaining the profitability and services of the heavily modified water body, whilst also working to provide a more naturalised flow regime for native ecology. On one hand, retaining as much water as possible serves to maximise profit and provide greater water security. On the other, retaining water to the detriment of ecology could lead to an unsustainable ecosystem, leading to issues for users downstream such as water quality problems like eutrophication. Such mismanagement could lead to a negative public perception as well as financial penalties being placed upon the water company for not adhering to environmental legislation. A field site (pictured in Figure 1) downstream of Holden Wood Reservoir, Haslingden, Lancashire (UK) was surveyed and flow and ecological data was obtained for the development of predictive models. The water body, Ogden Brook, is fed almost entirely by reservoir compensation flows at the investigation site. The surrounding floodplain is a narrow stretch of woodland running through a lightly suburbanised area. There are no water quality issues on site or other discernible anthropogenic factors that may have significant impact upon ecological populations outside of hydraulic variables.
Year: 2018