This guide, published by the Community of Madrid, through its Ministry of Economy and Finance, and the Foundation of the Energy Community of Madrid, designed as a tool to match the dual water / energy to the binomial water / well-scarce . Thus, the authors describe the relationship between the consumption of water and energy consumption, modern domestic saving devices, technologies for greywater systems, rainwater harvesting and thermal energy recovery in the sewer; or simple methods of leak detection in the sewage system for correction and repair.