Management of Municipal Network. Infratructures. Status Assessment and Requirement for Action using the Example of the Water Sector. Municipal authorities manage a substantial infrastructure portfolio, which includes safe supply in line with demand, drainage from residential areas, transport and communications. These municipal authority network infrastructures have a replacement value of CHF 460 billion. Long-term maintenance of the services associated with them is an important public duty. A working group from Wasser-Agenda 21 (Water Agenda 21) analysed the deficits which threaten the fulfilment of this duty using the example of the water sector. The article summarises the group’s findings, highlights areas where action needs to be taken and discusses appropriate countermeasures.