In the children’s counting “What should we build a house? Let’s draw — we will live!»The main rule of urban planning is laid down. Before you build a house, you must «draw» … its project. And the main section of the project is the design of water supply systems. Petersburg 300 years ago was conceived and designed by the type of European cities, there were no engineering communications at all. After several epidemics that arose against the backdrop of the monstrous pollution of the northern capital and channels, from where the townspeople took drinking water, the first installation of intending networks was made in the history of the city. Petersburg acquired sewage, and the length of the drains twice the length of the sewer of Paris.