Heavy precipitation in November 2007 hit the Southeast Serbia and Suva planina mountain area. They caused flood flows from 26th- 28th November, which severely damaged structures functioning in the regional water supply system ‘Ljuberadja-Nis’. At the outlet of Koritnica gorge in the village of Gornja Koritnica, an intervention on the pipeline along Koritnica River was planned. Hydrologic documents, aimed at flow estimation for damaged structures rehabilitation design, are shown in the paper. Flows of several probabilities of occurrence were obtained by usual calculation procedures for ungaged basins. However, some of the situations not typically present in the course of hydrologic base design are shown. These are: significant discrepancy between active and map based basin area, flow reconstruction based on the recorded flood flow trace, as well as reconstruction of the daily precipitation intensity.