REQUEST FOR CORRECTION OF THE 100-YEAR FLOOD IN THE NOVEMBER, 1999 REPORT ON DEER CREEK PREPARED BY THE LOS ANGELES DISTRICT, U.S. ARMY CORPS OF ENGINEERS

Background A concern in Southern California is computation of the risk of large floods in the Deer Creek Basin where large floods are a particular concern. Because Deer Creek does not have a systematic gaged flood flow record, the computation is based on the adjacent Day Creek record. Day Creek is a 4.56 square-mile watershed that has a U.S. Geological Survey (USGS) stream gage record for peak flood flow data from 1928 to 1972 In their November 29, 1999 report entitled Review of Debris Production and Level-of-Protection Deer Creek Debris Basin, the Los Angeles District of the U.S. Army Corps of Engineers (The District) presented the results of a statistical analysis of the Day Creek stream gage data. The report states that they used the following statistical methodology: