What is Impairing Our Streams?
Sources of Stream Degradation in Hamilton County The primary impacts to local stream ecosystems in Hamilton County can be categorized as 1. Hydrologic Alteration 2. Habitat Impairment, and 3. Water Pollution. A summarized description of these three categories of stream impairments follows. For a more in-depth description of these three categories of stream impairments - click here. 1. Hydrologic Alterations - "Flashy Flows" are eroding your property value and in-stream habitat. Many Hamilton County residents have complained that small streams flowing through their backyards have begun to exhibit "dangerous" and "destructive" flows in response to moderate rain events. These "flashy" flows threaten both public and private infrastructure, destabilize stream channels, destroy in-stream habitat, and flush-out fishes and other aquatic organisms at a frequency higher than that from which they can recover. The figure below shows two different "hydrographs" (plots of stream flow over time in response to a rain event) for an urban watershed vs. a forested watershed. |
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2. Habitat Impairment - the physical condition of the habitat within which fishes and other aquatic organisms live, is critical to their survival. In the absence of pollution or hydrologic alteration, a stream that has had its physical habitat directly altered will be unable to support a healthy community of fishes and other aquatic organisms. a) Healthy Headwater Stream Habitat |
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b) Impaired Headwater Stream Habitat.
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3. Water Pollution - Water pollution is a threat to human health and wildlife in Hamilton County. While industrial discharges of pollution ("point source" pollution) into streams is relatively easy to regulate, pollution delivered to streams in stormwater runoff ("non-point source" pollution) is a much harder problem to address.
For a more in-depth description of these three categories of stream impairments - click here. |