Taking advantage of the topography of the crowns in Barcelona, we are proposing hydro-electric power plants that use a loop system where turbines generate energy as water flows down, and pumps the water to reservoirs at low peak hours.  These would be placed in the existing sewers and drains at three different scales: the building scale, the barrio scale, and the urban scale. Team: Daniela Quesada, Luz Michelle Lavayen and Yashaswini Apte. Building scale . Putxet blocks We propose to generate Hydroelectric power using the ‘Pico-hydroelectric system’ for the buildings in Putxet. Electricity will be generated by individual buildings using the rain water collected on the terraces. This system shall be installed in buildings having a water head > 20m. Water turbines alongwith generators shall be located at the bottom of the terrace rain water downtake pipes. The energy generated by the water _owing over the turbine is converted into electrical energy that drives the generator. Electricity is generated using the speed of water _owing from a height. For buildings having water head < 20m, the rain water collected on the terrace shall be diverted to an underground reservoir within the block. From here it will be pumpedup to the overhead reservoirs on the buildings with higher water head. Depending on the size of the block, availability of space and quantity of water collected one or several underground reservoirs are proposed within a block. Incase adequate storage cannot be provided within a block, the excess water can be diverted to a reservoirs in other blocks or connected to the rainwater collection along the roads of the barrio. The rain water reservoirs ensures that the system can operate even during periods of low or no rainfall. Barrio scale . Putxet – Using the existing sewer infrastructure, a loop system would be put into place, using a high reservoir at the top of the crown, and a low reservoir at the bottom of the site.  The water collected during rainfall would be circulated down the streets and down the building terraces, passing through generators to create energy.  These same turbines of the generators would pump the water back up to the high reservoir at low-peak consumption hours.  The sewer systems of the main streets of the site would serve as both water collectors and return routes for the water, where all the other streets would simply collect the water. City scale . Barcelona The main idea of the proposal is to take advantage of the water collection through the drainage system and planning a water pumping system to generate electricity in the peak demand hours. For less impact, we are using the existing system and taking advantage of the deposits of rain water located around Barcelona. 1. Recognizing the existing water network in Barcelona. 2. Recognizing the potential sites according to topography where we can apply the model of our barrio Putxet in all Barcelona. 3. Connecting the existing water deposits with the pumping loops according to topography and using the main existing network.