In Indonesia we suffer from a lot of flash flooding in urban areas, caused by heavy rains landing on impermeable surfaces (concrete, tarmac, etc) and therefore not absorbing into the ground. All that running water rushes to streams, rivers or sewage systems which overflow and cause urban flooding.
So basically, if water is absorbed into the ground (infiltration) we reduce the risk of flooding. Tarmac has created a new, 'thirsty' concrete called 'Topmix Permeable' which is porous, allowing water to seep down through it into the ground below.
It absorbs up to 880 gallons, watch it in action:-