Revista de Engenharia Civil e Ambiental

Cost-effective Stream Gage Installation and Data Use for Small Watersheds

Abstract

Kurt O. Thomsen

One of the most important components of watershed monitoring is stream discharge. Currently small watershed monitoring is mostly limited to water quality sampling. Adding discharge measurements to current programs allows for the estimation of critical pollutant loading to the receiving stream. Additionally, discharge measurements can be used to establish a watershed water budget that in turn evaluates the status of groundwater storage in the watershed area. Flint Creek is a 59 square mile sub-watershed to the Fox River watershed in north eastern Illinois about 40 miles northwest of Chicago. Stream gages were constructed at five locations in the watershed. Once installed, the USGS conducted discharge measurements during various flow conditions to collect data to be used in stage-discharge relationship development. The resulting relationships were used to convert stage data recorded by the gages to discharge. At this point, stage-discharge data was used to estimate critical pollutant loading to the Fox River and the components of a water budget.