For at least the second time this year, storm drains were overwhelmed by heavy rainfall Monday night (Aug. 22), resulting in flooding on Oliver Street in Williams Lake.
The city of Williams Lake issued a statement Tuesday saying crews are working on clean up and repairs following the powerful thunderstorm.
Due to the rapid water load, storm drains overflowed and caused water to back up and flood some city streets.
Pat Mahood, Manager of Public Works, said the city’s storm water collection system is designed to carry storm flows in underground piping and in open ditches.
“Older areas of the city have smaller storm mains than newer areas as the design criteria has changed over the years, as has the frequency of high-intensity, short-duration events,” Mahood said, noting the change in intensity and the landscape of a city built on hillsides can lead to an overwhelming of the underground storm system.
“That’s not to say the system is deficient,” clarified Mahood.
He noted the overwhelmed manholes are typically located at the bottom of hills and lower areas in the city’s collection system and are not welded or bolted down to allow for relief of flows to the street curb and gutters. Hail can also increase drainage issues if it plugs catch basins.
City crews respond to high-intensity, short-duration events in known areas during these events and check the areas once the system can resume underground flow.
The city of Williams Lake has a 24-hour emergency line that can be reached at 250-392-5255 to report any concerns during these events.
Mahood said he was not aware of any reports of damages to property caused by these events.