The Use of Check Dams for Protecting Downstream Agricultural Lands in the Prehistoric Southwest: a Contextual Analysis

Check dams are common archaeological features found in ephemeral drainages throughout the American Southwest. Because of the region's environmental diversity, investigators have envisioned check dams as having served a number of functions. Interpretations of function have long been normative, based largely on ethnographic parallels that have recently been the subject of criticism. A contextual analysis involving evaluation of agri- cultural features in relation to the local environment and human-ecological conditions appears to be a more appropriate method of examining such features. Such an assessment of one recently discovered site in western New Mexico resulted in an interpretation of check dam function that previously had not been recognized in the Southwest. Analysis of runoff and sedimentation characteristics indicates that check dams in at least one locale served to protect large fertile tracts of downstream land from periodic inundation and influxes of poor-quality sediment. The implications of these findings are discussed in regard to other check dam sites in the region