This is equivalent to all expenditure on basin management and flood protection plus one third of all expenditure on policy and regulation. According to the User- and Polluter-Pays principles, users of retail water services should pay for the full cost of urban bulk water supply services and wastewater treatment. In Mexico, however, they only pay about two-thirds of the cost of urban bulk water supply (since CONAGUA collects MXN 2 billion to provide services on which it spends MXN 3 billion) and only half of the cost of wastewater treatment (following the share of user’s contributions to the water supply and sanitation sub-sector).