The Autrian ÖWAV guidelines concerning the sewer design and the storm water management are being revised. Therefore a project called ÖKOSTRA was initated to develop regional IDF curves (intensitiy, duration, frequency) for the design work of Austrian sewer structures. Processed material or digitalised precipitation values are put in a data bank and the amount of a certain design value of precipitation hN for the requested duration D and the return period T can be investigated according to the ÖKOSTRA guidelines. Since the end of the project it is possible to get regional IDF curves for the densely populated aereas in Austria (places with more than 5000 inhabitants).