Abstract
<jats:p>The existing national regulation for calculating stormwater runoff in urbanized areas does not adequately reflect current climatic realities, as it is based on outdated rainfall intensity data collected more than 40 years ago. The present study proposes an updated and scientifically grounded methodology. A key contribution is the introduction of a more precise zoning of the country – expanding from two to twelve distinct zones, for each of which individual intensity-duration-frequency (IDF) relationships have been developed. These are based on statistical processing of empirical rainfall data and an internationally recognized theoretical model. The proposed formulas for each zone demonstrate significantly improved accuracy compared to the existing methodology.</jats:p>