The revision the Drinking Water Regulations will come into effect on 01.11.2011. Surveillance authorities and owners of drinking water supply systems had hoped for simplifications and reductions because of the new arrangements. According to the official statement for the revision the legislature intended to create more clarity, consider new scientific findings, to change regulations that have not been proved to close regulatory gaps, to deregulate and to increase the high quality standards. A detailed examination of the regulation text, however, raises doubts. The new classification of water supply systems requires different modalities of registration, water analyses and official observation, which will complicate the work of the authorities. In particular, the implementation of requirements of registration and examination for the owners of commercial and publicly-operated large hot-water systems in accordance with DVGW Worksheet W 551 requires more effort. According to the estimated 30000 cases of legionellosis in Germany the need for a check of such systems for Legionella, however, is not called into question. Furthermore, the development of sampling plans and the monitoring of mobile water supply systems requires more work for the health authorities.