The maintenance of catch basins and sewer pipes depends on the history of the particular neighbourhood. During normal flow conditions, local problem areas are identified, investigated and scheduled for maintenance. Typically, the sewer pipes are flushed and cleaned, and debris is removed from the catch basins. In more severe cases, a sewer may require re-lining. A problem drainage location may be visited by a crew once a year, with the cleaning operation taking about two hours.

Catch basin sumps along bus routes and major roads that are sanded get cleaned once a year. All other catch basins are only cleaned if a specific problem is noticed or reported.

No. Flooding events are typically not related to maintenance. Flooding tends to occur because the system is unable to handle a high volume of water as seen during a severe storm event. In this situation, water pools on the surface because the sewer pipes are full of water and have reached capacity.