Water is essential for life and social and economic development. Its exploitation and use must be well planned and managed in a sustainable manner. In many developing countries, lack of adequate, clean, and safe water, pollution of aquatic environments, and the mismanagement of natural resources are still major causes of environmental health problem and mortality. With a human population that is continuing to grow, the management of water resources will become of vital importance. In order to accommodate more growth, sustainable freshwater resource management will need to be included in future development plans and implementations. One of the major environmental issues of concern to policymakers is the increased vulnerability of surface and groundwater quality. Furthermore, the main challenge for the sustainability of water resources is the control of water pollution. To understand the sustainability of the water resources, one needs to understand the impact of future land use and climate changes on the water resources. Providing safe water and basic sanitation to meet the millennium development goals will require substantial economic resources, sustainable technological solutions, and courageous political will. A balanced approach to water resources development, on the one hand, and controls for the protection of water quality, on the other hand, is required for sustainability of water resources and environmental public health. In addition to providing improved water and sanitation services, we must ensure that these services provide safe drinking water; adequate quantities of water for health, hygiene, agriculture, and development; and sustainable sanitation approaches to protect health and the environment.