This paper provides, in tabulated and summarized forms, details from a total of 23 North American dams and levees which have been remediated against seepage and the consequences of seepage, by using some form of “positive cut-off.” The purpose of the paper is to provide perspective to potential users of the various techniques in relation to such factors as depth capability, geotechnical suitability, constructability, QA/QC and verification, and cost. The technological scope of the paper is limited to projects involving concrete walls (“diaphragm walls”) built by panels or secant piles, soilcrete walls built by the Deep Mixing Method, soilcement
and soil-cement-bentonite walls, typically installed by backhoe. Input is requested from interested readers to expand and modify (as necessary) the information presented herein. The paper assumes a certain level of familiarity with the respective techniques on the part of the reader, and so does not describe their detailed sequential steps of construction.