In practical terms, such implementation is then based on multiple technical measures designed to counter the adverse effects of urbanization on aquatic habitat. These measures are considered in the provision of urban water services, which cause modifications of, and impacts on, aquatic habitats. In the field of water supply, the essential measures include managing the import of water into urban areas – excessive withdrawals affect flow regime in aquatic habitats and contribute to returns of large volumes of wastewater. The use of secondary sources of water (e.g., rainwater) and water and wastewater reclamation and reuse all offer good solutions conserving high quality water for appropriate uses. Urban drainage and flood protection exert pronounced impacts on aquatic habitats, including changes in flow regime, physical habitat structure, energy sources, chemical fluxes, and biotic interactions.