The World Bank's 2004 WaterResources Sector Strategy focused on the need for both waterresources management and development in dealing with growthand poverty alleviation. Planning and design of newhydraulic infrastructure for water supply and sanitation,food production, hydropower generation, flood protection,ecosystem restoration or other such purposes require dealingwith all elements in the interaction among land, water,vegetation, human intervention and climate variability andchange, with an emphasis on the end-user. They also requirethe simultaneous consideration of technical, economic,institutional (governance), political, financial,environmental and social factors, as called for in theBank s 1993 Water Resources Management Policy. To providehigh-level insight on the key hydrology issues involved, agroup of world class experts gathered at a workshop held atWorld Bank Headquarters in November 2008. The workshop wasorganized by the Hydrology Expert Facility (HEF) of theWater Anchor. The presenters discussed advancements in keyhydrologic topics that were selected for their relevance toBank operations. The focus was on potential implications forthe Bank s development assistance on water projects,programs and policies.