Standard DWA-A 117E Dimensioning of Stormwater Holding Facilities

In order to reduce the amount of runoff caused by precipitation, in many cases, the temporary storage of rainwater and combined wastewater in stormwater holding facilities is necessary to protect the drainage systems from overloading and/or limit their dimensions. In this context, in view of the high investment costs, an assessment of stormwater holding facilities in line with economic aspects is of the utmost significance. This Standard offers two options for determining the volume of stormwater holding facilities: dimensioning based on statistical precipitation data with the simplified procedure for small and simply structured drainage systems, and dimensioning based on long-term precipitation-drainage simulation for all cases of application. Standard DWA-A 117 has been editorially revised with specific regard to the adaptation of the abbreviations to the requirements of the Standard ATV-DVWK-A 198, and is mainly aimed at planning engineers.