ABSTRACT:

Field measurements of discharge and stream channel bathymetry are provided from near the abutment of the former South Fork Dam (breached in 1889 causing the Johnstown Flood of 1889). This, combined with 15-minute stream stage data (HOBO logger) helped in the establishment of a new stream gage (and stream rating curve over the period of study) in Johnstown Flood National Memorial in the South Fork of the Little Conemaugh River, Cambria County, PA, USA. Logger data from the South Fork are made available here.

Using Stage IV Precipitation Data from UCAR extracted for the Little Conemaugh and South Fork basins via R (example provided for April 17 for the Little Conemaugh) and stream gage data from East Conemaugh (via USGS; station 03041000), unit hydrographs (optimized via a merit function for peak discharge) were established for storms exceeding 8 hours in duration. These unit hydrographs were then convolved with design storms to probe possible peak discharges in the Little Conemaugh watershed and the South Fork sub-basin. Unit hydrographs and design storm analyses are provided here.