it then provides an overview of oecd s framework for financing water resources management and uses this as a basis to analyse existing financing arrangements for water management in the netherlands and identify opportunities to improve financial sustainability assessing total water management costs is not a trivial task because of the many different parties involved in water management see chapter which have specific functions responsibilities budgets and ways of financing their expenses this includes eur million of costs for wastewater treatment by the regional water authorities and eur of costs for collection and discharge of rainwater and wastewater by municipalities it also includes eur of expenditure by drinking water companies which in part consists of costs related to the purification of poor quality water