This report focuses on water and water-related issues and investments, with a particular focus on reducing the vulnerability of water sector investments to the impacts of climate change. It provides a first version of a tool that can be used to assess exposure and screen the investment portfolio on a regional basis. Its main objective is to provide analytical, intellectual and strategic assistance to the regions for incorporating adaptation to climate variability and change in their work programs. Using the existing knowledge and additional analysis commissioned, it illustrates that climate change is affecting the hydrologic cycle and the projected future hydrology will have a direct impact on the water resources base availability, usage, and management. The report addresses the stress on and vulnerability of the water systems through use of reliability, resilience, and robustness as the key indicators of sensitivity of water systems for climate induced failure.