Regional Storm Drainage System

The Regional storm drainage system is separate from the sanitary sewer and water supply systems.

The Regional Municipality of Durham provides and maintains ditches, catch basins, maintenance holes, culverts and underground storm sewer pipes. We do this to collect stormwater run-off from rainfall or from melting snow and ice on Regional roads. We carry this to discharge points called outfalls.

We use stormwater quantity and quality controls to reduce stormwater outfall impacts on our rivers, creeks and lakes.

Urban areas

In urban areas where there are curbs and gutters along the road, stormwater is usually collected in catchbasins. The catchbasins take it to the outfall through an underground storm sewer system. Maintenance holes allow for access to the underground pipes.

Rural areas

In rural areas, open ditches and culverts collect and carry stormwater to the outfall.

Maintaining the Regional storm sewer system

We carry out maintenance on the existing Regional storm sewer system to maintain maximum capacities and extend the life of the system.

Maintenance includes:

• Inspection and cleaning of catchbasins every year. We inspect maintenance holes every two years to determine cleaning and repair programs. Loose or noisy lids are replaced or repaired.
• Repairs or replacement of pipes that are damaged as soon as practical.
• Inspection of storm sewers by video every 10 years or as required when planning a road construction project.
• Cleaning and maintaining stormwater quality control devices (such as oil grit separators) every year.

We are only responsible for storm sewers on Regional roads. Contact us to report any concerns about storm sewers on Regional roads.

Please report issues with storm sewers on area municipality roads and with stormwater management ponds to the relevant area municipality.

New storm sewer systems

We typically design new storm sewers for a one in 10-year storm event. Excess run-off from less frequent and more intense storm events follows planned overland flow routes.

We design, approve and construct stormwater systems on Regional roads as part of the capital road program. The design and construction specifications for Regional services provide the Region's standards for storm sewer design and construction.

Stormwater from new development

We are responsible for ensuring that stormwater flows from new developments do not affect the capacity of the Regional storm sewer system. When land is developed, water from areas such as concrete or asphalt will run off more quickly into a storm sewer system. This can cause capacity issues during rainfall

For new development proposals, we review the potential impact on the Regional storm sewer system through a Stormwater Management Report. Typically, new developments are required to maintain stormwater flows at pre-development levels through the provision of stormwater storage within the site and a restricted flow into the Regional storm sewer system.

Sewer by-law

The Sewer Use By-Law No. 55-2013 restricts what can be discharged into the storm sewer system.