The Legacy of the 1948 Underseepage and Crevasse Maps, Lower Mississippi River Levees

Seepage and crevasse maps showing levee performance from the 1937 and 1945 floods in the LMV were compiled as part of the comprehensive study by USACE 1956 into levee underseepage and its control. This map folio was limited in distribution, never officially published as a technical memorandumreport, and was thought to have been lost. The map folio was discovered as part of ongoing research into sand boils in the LMV and consists of 40 15-min scale maps extending from Cairo, IL, to New Orleans, LA. The complete set of maps was scanned and is being presented herein for wider dissemination. This map folio identifies sand boil locations, historic crevasses, severity of seepage, and extent of seepage control measures that were present prior to 1945. A historic summary is presented for background information and importance to ongoing studies of seepage control and internal erosion of levees.