LAKE SHENANDOAH, ROCKINGHAM COUNTY, VIRGINIA: ESTIMATION OF NUTRIENT AND SEDIMENT LOADING

Lake Shenandoah, located in Rockingham County, Virginia and owned by the VDGIF is a recreational reservoir that supports a sport fishery for warm water fish species. The lake experiences chronic fishery and aesthetic management problems due to macrophyte growth, sedimentation, and eutrophication. A study done in 1996-97 showed there was a problem with nutrient and sediment loading due to past agricultural practices and land development in the watershed. The purpose of this study is to assess the sediment and nutrient loading and to determine if it has significantly changed in the past ten years since the land use has changed from primarily agricultural uses to suburban development. Water quality parameters including pH, ANC, Ca2+, Mg2+, Na+, K+, Cl-, NO3-, SO42- , ammonia (NH3/NH4+), turbidity, conductivity, and total phosphorous were measured for both feeder streams entering the lake. Results from both the lake and stream water, and sediment chemistry showed that there are excess nutrients and considerable sediment buildup in the prongs of the lake. Results have shown that Congers Creek is the greatest contributor to the eutrophication of Lake Shenandoah as it delivered 48.6% of the total phosphorus, 77.1% of the nitrate-nitrogen, 66.4% of the ammonia-nitrogen and 48.3% of the total transported solids. Although development has leveled off in the watershed, sediment and nutrients will continue to be delivered to the lake via the feeder streams. Data collected for this study will provide information useful for management directives for mitigation and restoration of Lake Shenandoah.

Additional Abstract Information

Student(s): Melinda Ellis, Anne Battaglia

Department: Chemistry and Biochemistry

Faculty Advisor: Dr. Daniel M. Downey

Type: Poster

Year: 2011