Eagle River Inventory and Assessment (2)

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of minimum flow requirements in "streams of little to perhaps moderate value as far as the fisheries resource is concerned" and "where encroachment by diversion, pollution, and development is not anticipated as a serious problem" (Nehring, 1979). The method used to quantify instream flows on the Eagle River main stem is not designed to serve as the primary decision making tool for managing flows in river systems such as the Eagle. It does not address several key factors linked to low flows such as recreation, water quality, land use changes, wastewater dilution, and temperatures. ES.4.5 Water Quality Water quality is inextricably linked with water quantity and flow regime. For example, the low-flow regime of the Eagle River influences numerous aspects of water quality including; • growth and persistence of algae on the river bed, • flushing and dilution of fine sediment from tributaries and land disturbance, • concentrations of nutrients and oxygen below wastewater discharges, • late summer temperatures for Coldwater fishes, and • dilution of pollutants from mine sites and urban runoff, A future challenge for stakeholders in this watershed will be to maintain and in some cases improve water quality despite greater demands on the valley's water resources due to larger volumes of treated wastewater and urban stormwater runoff entering the river. With this as a general context, we can state that water quality is good in most parts of the watershed, due to maintenance of key physical and ecological processes in the headwaters comprising the vast majority of stream length in the watershed. Room for improvement remains and changes will be necessary to avoid further degradation of water quality. ES.4.6 Nutrients Sources of nutrient additions above background levels in the Eagle River watershed include: • wastewater and septic systems, • fertilizers and animal waste, • soil erosion, Eagle River Inventory and Assessment ES-7