Over more than a decade, Ebert & Associates has, largely in the context of studies carried out for the Department of Justice and the Bureau of Indian Affairs, developed methods which integrate data from historic aerial photointerpretation, historic maps, informant interviews, and fieldwork to discover, characterize, and quantify evidence of historic and prehistoric agricultural water use. Variations through time in historic irrigation can be quantified, and given adequate aerial photographic coverage through time, priority dates established in some cases. Of course, evidence of prehistoric agricultural water use that can be supportably associated with current property owners provides the earliest priority dates.
