Looking for High-Water Marks

Daniel McCay and Chris Henry, U.S. Geological Survey hydrologic technicians, search a neighborhood south of Denham Springs, Louisiana, for high-water marks August 26. The term high-water mark refers to the debris flood waters will leave on walls, buildings and trees. This thin line of residue is an indicator of how high the waters reached, yet the fragile nature of these marks means they must be flagged as soon as possible. Because of this, more than 20 USGS personnel from several states have been working in south Louisiana from dawn until dusk to flag and survey as many high-water marks as possible.