Various associations and organizations has been developing and maintaining, for many years now, a comprehensive regulatory framework on the issues of urban water management. These include:
German Association for Water and Waste (DWA),
Association of Engineers for Water Management, Waste Management and Land (BWK) e.V.
German Institute for Standardization e.V. (DIN)
Research Society for Roads and Transportation (FGSV)
Professional association operating on stormwater usage e.V. (fbr)
In addition to the regulations, working groups, regularly release leaflets and publish progress reports. The following applies in respect to stormwater management.
Technical rules from trade associations, as the German Association for Water and Waste (DWA) and the German Institute for Standardization (DIN) have specs and regulations that are recommended and endorsed. However, these recommendations, are not legally binding unless they are specifically mentioned in the contract. One example is the reference to the ATV Worksheet A128 in the NRW-administrative regulation "Requirements for the public precipitation drainage in the mixing process". In these cases, compliance with the technical rules is legally binding.
An overview of relevant associations and subjects are in the following table (In German).