Key Findings & Management Recommendations
The Appalachian LCC-funded study is the first region-wide assessment to document “flow-ecology” relationships – showing connections between observed impacts under current water withdrawal standards (based on daily water gauge data collected over the last 15 years and fish surveys) and the decline in freshwater fish communities.
Based on the assessed relationships and factors such as season, stream size, and projected expansion of natural gas development in the region, scientists developed models showing how water withdrawals impact sustainability of aquatic ecosystems. Cornell researchers also applied a model to vary water withdrawal scenarios – for example from current standards to a more seasonally variable scenario – that provided critical information on how flow regimes can be modified to achieve a balance in meeting both human/energy water needs and those required to maintain healthy ecosystems and diversity.
Key findings and recommendations from the research include:
- Flow-ecology relationships indicate fish are sensitive not only to changes in low flows, but also to changes in a variety of flow components (season, median, and high flows). This has important implications for setting sustainable flow standards and designing monitoring campaigns.
- A considerable number of streams are at high risk of flow alteration due to withdrawals during the summer and fall seasons – especially smaller streams in the southwestern (western portions of Ohio River Basin) and northern (headwaters of the Upper Susquehanna and Hudson River Basins) sections of the region.
- Though these high-risk streams are individually small, combined they drain the majority of the study region.
- Fixed minimum aquatic flow standards that do not consider seasonal changes in flows and throughout the year may not be adequate to sustain fish populations and aquatic biodiversity.
- But a balance can be realized if flow standards due to water withdrawal regulations vary with stream size and season and thus provide the necessary balance between human needs and flows needed to sustain fish and aquatic ecosystems.
