 harder to retrench. Preliminary data suggest that spending levels have increased in 2004. Investment is also discouraged by the externalities associated with the provision of sewage and water treatment services, and because water/sanitation networks are costly, investment maturities are long, and rates of return are relatively low. More importantly, the drop in public investment has not been compensated by an increase in private investment, which can be attributed predominantly to a lack of clarity about which level of government is responsible for service delivery and regulation in the sector. This is particularly acute in the metropolitan regions, which straddle municipal borders. As a result, no regulatory framework or regulatory agency is currently available for this sector. The National Water Agency (ANA), created in 2001, is responsible for managing and regulating surface water resources but has no purview over water/sanitation services. Water sector investment requirements World Bank Research Working Paper 3102 (Fay and Yepes, 2003) suggests that over the period 2005-10 for the developing world an amount totalling the equivalent of 2% of GDP for all developing countries would be required to be invested in the maintenance of existing and new infrastructure, equivalent INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 5. THE IMPACTS OF CHANGE ON THE LONG-TERM FUTURE DEMAND FOR WATER SECTOR INFRASTRUCTURE to 0.44% of GDP annually. For the world the equivalent figures are 0.6% of GDP totalled over five years or 0.12% of GDP annually. From Annex II of the same report the calculated percentages of GDP given are set out in Table 5.14. Table 5.14. Expenditure on water and sanitation as a percentage of GDP New infrastructure Maintenance Total Water Sanitation Total Water Sanitation Total East Asia and Pacific South Asia Europe and Central Asia Middle East and North Africa Sub-Saharan Africa Latin America and Caribbean High income Low income Middle income Develo