Water Resources Research Act Program

Details for Project ID 2012MD262B

Quantifying remobilization rates of legacy sediment from Maryland Piedmont floodplains

Institute: Maryland
Year Established: 2012 Start Date: 2012-07-01 End Date: 2013-08-31
Total Federal Funds: $66,326 Total Non-Federal Funds: $159,244

Principal Investigators: Andrew Miller

Abstract: Sediment has long been recognized as a critical pollutant affecting water quality and habitat in Chesapeake Bay. Recently the U.S. EPA issued a “pollution diet” for the Bay in the form of a Total Maximum Daily Load (TMDL) document that includes a mandate for a 20 percent reduction in the mass of sediment reaching Chesapeake Bay (U.S. EPA, 2010). Erosion of "legacy" sediment from streambanks in the Bay watershed has been characterized as a major part of the problem and this topic has gained wider attention with the publication of recent papers describing the impact of historic mill dams on sediment storage in the landscape. Despite the attention devoted to this topic, we have no quantitative information on a regional basis to assess the cumulative amount of legacy sediment that has been remobilized from storage along streams either with or without mill dams, how rapidly it is being removed, whether the amount being remobilized is a large fraction of the total watershed sediment flux in Maryland Piedmont watersheds, or whether the amount being remobilized from watersheds with historical mill dams represents a major concern for the health of Chesapeake Bay. Improved knowledge about the relative importance of these sources may be relevant for management decisions. This study will use airborne lidar, historical maps, high-resolution aerial photographs, field surveys and sediment sample analysis to develop quantitative estimates of the rate of legacy sediment remobilization from floodplains in the Baltimore County portion of the Maryland Piedmont.