Water Resources Program  |  State of Water Resources
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It is likely that the majority of streams in the County would presently fail Virginia’s biological standard and, thus, be considered impaired. Local impairments are caused by a variety of land uses and activities – stressors that are both within and beyond the authority of the County to control.

 

HEALTH OF STREAMS AND LAKES

Streams and lakes are assessed by the Virginia Department of Environmental Quality (DEQ) using chemical and biological data collected by themselves and various other organizations, including citizen monitoring groups such as StreamWatch, a program of the Rivanna Conservation Alliance.  DEQ is required by the Clean Water Act to publish the results of their state-wide assessment program every even-numbered year in a document entitled Water Quality Assessment Integrated Report. The status of Albemarle County’s streams and reservoirs according to the 2014 Report is summarized in the map below.

For many streams within the County there are not enough data to determinewhether the stream is healthy or impaired. For streams in which a determination was made, about 30% of stream miles were healthy and 70% were impaired. The types of County stream impairments are summarized in the pie chart below. Note that the term benthic – which means “bottom-dwelling” – denotes that a stream does not support healthy and diverse aquatic life as indicated by assessments of macro-invertebrate organisms (aka, bug surveys). 

Both the DEQ report and a StreamWatch 2011 Land Use Study predict that less than half of the streams within the County are healthy by Virginia standards. StreamWatch additionally concludes that, based on data from its representative monitoring sites, the overall average condition of streams within the Rivanna basin has not changed significantly over the past ten years.

CAUSES OF IMPAIRMENTS

Research indicates a strong correlation between the health of lakes and streams and upstream land use. Undisturbed, densely forested lands result in the healthiest streams. As land use intensifies the volume and intensity of runoff increases– leading to channel scour and subsequent sedimentation. In addition, land use intensification introduces more pollutants into the watershed and more efficient pathways for these pollutants to reach streams.

To a large extent, the County’s water resource programs serve to reduce or mitigate the impacts resulting from intensified land use.