Study to determine discharge at 50-percent flow duration and ordinary high water for streams in Louisiana

Techniques are presented for estimating the discharge at 50-percent duration and "ordinary high water" on ungaged streams in Louisiana that have drainage areas of less than 3,000 square miles. Discharge data from 91 gaging stations were used in developing the techniques. The discharge at 50-percent duration can be estimated if the drainage-area size and mean annual precipitation are known. The "ordinary high water" can be estimated if the drainage-area size, mean annual precipitation, channel cross section, channel slope, and Manning's roughness value are known.