Digging into ditches: A historical-geographic analysis of agricultural drainage ditches on Maryland’s Eastern Shore

Abstract

To this day, agricultural drainage ditches form a fundamental alteration to Maryland’s Eastern Shore; however, the environmental impacts of the ditch network are relatively unknown. This ditch network has evolved in recent decades and now includes newer, larger, mechanically-dug ‘tax ditches’, introduced in Delmarva as methods of flood control due to the flat, swamp-like geography of the land. A mixed-method geographic analysis looked at this small-scale local water management infrastructure from several angles: (a) historical, utilizing Nabb Center archive research, documents obtained from various county offices, and oral history to establish the extent of the ditch network, (b) comparative land use, using applications of GIS mapping to display current ditch systems in relation to land use categories, and (c) spatial implications, assessing hydrologic proximity and drainage trajectory to the Bay. Information on ditches, both current and historical, is scattered and not easily found. This supports the need to compile this information for future reference and research. The hydrologic network shows tax ditches flow toward the Chesapeake Bay as an extension of natural streams, and land use maps display the great extent to which tax ditches are located in agricultural areas, yet still close to development. The question that remains is how much, volumetrically, of this ditch network drains into the Bay, and what water quality implications does this pose? This preliminary study has opened avenues for future research looking into this unique drainage network of Maryland’s Eastern Shore.