A Piece of History
Historically, urban water problems have been solved using an old theory that promotes having excess rain water flow as quickly as it can to the lowest basin point. In this way, water travels from neighborhood to neighborhood, causing the last one to be flooded.
This results in great expenditures in hydraulic constructions such as sewers, storm drains, curbs, etc. That means an obvious increase in costs, and as we know, cost is always one of the most important parameters when we think about any type of building construction.
This theory also promotes higher velocities to make the water flow quicker. Thus it is common to see, in urban or rural communities, concrete channels that are cheaper and easier to construct than landscaping (forming) and grass.
Yesterday, urbanization was not always considered in land use planning. This means that sometimes hydraulic buildings were constructed to serve a certain quantity of population, but then it was duplicated. Sometimes buildings had to be re-constructed, duplicated, or taken out of use, and this raised costs.