Big hole creating ‘expressway’ for Calgary stormwater

An 'expressway' for storm water currently under construction in Calgary will help prevent storm sewers from backing up with water from higher elevations and reduce flooding.

A hole big enough to be seen from aircraft flying overhead is just a tiny part of Calgary’s flood mitigation work.

The 13-metre diameter hole along 10 Street N.W. is big enough to lower a bus into it and goes 20 metres underground. A boring machine will make its way to 7 Street N.W. and Memorial Drive, creating a tunnel to connect with the Bow River.

Ward 7 Coun. Terry Wong said the upper plateau separation is designed to redirect stormwater from higher elevations directly into the river.

“It basically separates the storm sewer water from the upper part (north of Hillhurst/Sunnyside) and not having any overflow into the lower area,” Wong said.

The chair of the Hillhurst Sunnyside Community Association’s flood committee said it’s one of the most important flood mitigation projects for Sunnyside.

Charlie London described it as an “expressway” for water.

“It will take the water directly into the river rather than flowing through Sunnyside, because when the river is even a little bit high and the river gates are closed, that water in the past — and even today — backs up into Sunnyside,” he told Global News.

A resident of the area since 2005, London said water from the North Hill backing up into Sunnyside has been a frequent challenge.