Why is flooding such a problem in Sun Valley?
As in most of our heavily urbanized area, about two thirds of the ground in Sun Valley is covered by hard, or impervious, substances. They keep rainwater from soaking into the soil, so it runs off over the pavement instead. The area is also quite flat, and stormwater takes longer to move through than it does in hillier sections. In other parts of the city, storm drains help carry the water away, but there are no major drains in the Sun Valley watershed. Even a moderate rainfall quickly overwhelms the few minor drains, and rainwater backs up on streets and in low-lying areas.
