The investigation of sediment deposition in Lake Corpus Christi was initiated by researching the published and unpublished sediment data for the 1972-85 water years for stations located upstream and downstream of the lake. Regression analysis was used to fill in the missing data. Data were tabulated for monthly discharge (acre-feet) and sediment load (tons, acre-feet, and percent by weight). Yearly totals and cumulative averages were computed and included in the tables.
An estimated 10,300 acre-feet (wet volume) of sediment has been deposited in Lake Corpus Christi during the 14-year period of record (1972-85), an average of 736 acre-feet per year (wet volume). An earlier study by the U.S. Soil Conservation Service, based on 1942-48 changes of lake bottom contours, estimated that 736 acre-feet per year of suspended sediment had entered Lake Corpus Christi during that 6-year period.
Some difference was found in comparison of the results of the U.S. Geological Survey (Water Resources Division) study and the McCaughan and Etheridge Consulting Engineers study. Total sediment outflow from Lake Corpus Christi was estimated at 177 acre-feet (dry) by the Geological Survey and 1,070 acre-feet (dry) by McCaughan and Etheridge Consulting Engineers. This difference may be due to construction of a new dam, completed in 1958, that is higher and inundated the old dam.
