Verification of Reference Elevations at USGS streamgage in SD

Student hydrologic technician Jackie Eldredge holding the rod over one of the known reference points at streamgage 06404998, Grace Coolidge Creek near Game Lodge near Custer, SD. One step in ensuring consistent streamflow data is verifying that the reference elevation at the streamgage stays consistent and that any changes are documented. All of the USGS streamgages have multiple reference marks to ensure that even in extreme flooding events, that the high water marks can be referenced back to a known elevation. As part of this process, technicians go out and survey all of the reference marks on a designated interval that ranges from every year to every three years.