It then provides an overview of OECD’s framew'ork 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 1), which have specific functions, responsibilities, budgets and ways of financing their expenses. This includes EUR 1 292 million of costs for w'astewater treatment by the regional water authorities and EUR 1 360 of costs for collection and discharge of rainwater and wastewater by municipalities. It also includes EUR 1 370 of expenditure by drinking water companies (which in part consists of costs related to the purification of poor quality w'ater).