Storm sewers carry rainfall and other surface runoff directly to the nearest creek, stream or river, frequently with limited or no treatment. Everyone plays a role in preventing pollutants from entering the storm sewer system and damaging the water ecosystem. Over time, stormwater collection has graduated from being concerned only with draining excess water away as quickly as possible, to flood and erosion prevention in waterways, to restoring water quality before releasing to nearby waterways.
Various practices are used to manage stormwater runoff throughout its journey from rain to river. Stormwater management begins with lot-level controls where rain first drops. It then proceeds to conveyance controls which help transport stormwater. Finally, end-of-pipe measures treat stormwater before it is discharged into our local waterways.
The City of Ottawa maintains a network of culverts, storm sewers and municipal drains that transport stormwater to nearby creeks, lakes or rivers. In Ottawa, the stormwater system includes:
- More than 2,700 km of storm sewers
- More than 300 stormwater management facilities including 133 wet ponds, 100 dry ponds, 12 stormwater pumping stations, underground storage, bioswales, and oil-grit separators
- 1,200 km of municipal drains in rural areas