The city maintains more than 471.6 miles of stormwater pipe, 16,000 catch basins, over 3700 outfalls, over 200 miles of ditches, 22 stormwater ponds as well as 16 pump stations and the flood wall system downtown. Norfolk also provides quarterly street sweeping for every roadway with curb and gutters throughout the city. The Division of Storm Water Management repairs and cleans these structures as needed. When excessive rain causes flooding, the city responds to flooding complaints and cleans out clogged storm drains during the precipitation event.