Stream Bank Erosion and the Chesapeake Bay TMDL – Loading Rates and Bay Model Assumptions
Sediment and nutrient loading to the Chesapeake Bay from its tributaries is a serious problem that has impaired the Bay and caused dead zones. It is assumed that pollution from agricultural lands is the dominant source of sediments and nutrients. However, the presence of legacy sediments along streams behind historic mill dams is a potentially significant source of sediments and nutrients as well. This study examined five streams in Lancaster County, Pennsylvania and measured erosion rates on streams with and without legacy sediments. Erosion rates during the four–month monitoring period were greatest on streams with legacy sediments, averaging 1.5 feet lateral erosion over a 4.4 month period on outer stream bends. Erosion rates on straight channel segments of streams with legacy sediments averaged 0.6 feet over the monitoring period. The control stream without legacy sediments averaged 0.02 ft of lateral erosion along its channel. Erosion rates were greatest when stream banks were higher and with greater bank angles, although these factors explained only about 40 percent of the variability in erosion rates. The mass of sediment, nitrogen, and phosphorus eroded (lbs/ft/yr) was much greater than assumed by the load reduction assumptions in the Chesapeake Bay watershed model. Stream bank erosion caused by the numerous historic mill dams in Lancaster County and elsewhere in the Bay watershed needs to be addressed as a major source of sediment and nutrient loading to the Chesapeake Bay and targeted for load reduction restoration practices.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 2011-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites