Ottawa Installs Vortex Valves for CSOs

Hydro International, a provider of products and solutions for stormwater, wastewater and combined sewer overflows, will supply the city of Ottawa, Canada, with 940 Reg-U-Flo® Vortex Valve inlet control devices to alleviate basement flooding in the downtown area.

The city expects to install 485 devices in a two-phase project by the summer of 2009. Ottawa is planning to procure and install another 455 Hydro inlet control devices in mid-2009 as part of a large-scale upgrade of the drainage system in the O'Connor Street area, just south of the St. Lawrence River.

The city has reported a large number of basement flooding incidents over the years in the combined sewer area resulting from surcharging of the city's combined sewers, which carry wastewater and stormwater in the same pipes. When too much stormwater enters streetside catchbasins, the sewer can surcharge, leading to flooded basements in low-lying areas.

The city plans to use the vortex valves to restrict the stormwater flows into the combined sewers. High stormwater flows initiate a vortex within the valve, which has a snail or conical shape. The vortex restricts the water that can pass through the device. When head pressure builds, the vortex circulation allows an air core to form and prevents water from surging to the combined conveyance system.

"While we work on a long-term solution to our combined sewers, we needed to solve the basement flooding problem quickly," said Darryl Shurb, a senior project manager in the City of Ottawa Public Works and Services Department.