Passersby look at the portion of First Street North covered by floodwaters of the Assiniboine River. The city is measuring the river height at the First Street bridge four times a day to help officials prepare for future floods.
Measuring the Assiniboine River height four times a day is helping the City of Brandon prepare for floods in the future.
Patrick Pulak, the city’s director of engineering services, says that data collected will help to anticipate flood levels in future floods, just like the 2011 data is helping now.
"The data is used to make what we call a rating curve," he said. "Based on the 2011 rating curve, we were able to see where things were going to go."
The river height is measured by the city at the First Street bridge at 7:30 a.m., noon, 5 p.m. and 9 p.m. It is typically done by a two- or three-person survey crew.
A laser level is placed on a tripod and uses a rod to check the level of the river, Pulak said. Nothing has to touch the river to find out the height.
"The height used to be tested by a level mounted on the First Street bridge, but it has been malfunctioning," he said. "We are still collecting that data, but the official information comes from the measurements taken with the level and rod."
The level attached to the bridge is around nine years old and will probably be replaced before the end of the summer, he said.
The only measurement taken by the city is the river height, whereas Manitoba Infrastructure and Transportation looks at the cubic feet per second of water moving through.
"We don’t have the instruments to test CFS," Pulak said. "We use the data provided by the province with our measurements to develop the rating curve."
Mayor Shari Decter Hirst tweeted a photo of the Acoustic Doppler used by Manitoba Infrastructure and Transportation to measure the river in Brandon.
The CFS is measured by the province twice a day at 18th Street.
Pulak explained that CFS is more easily measured there because all the water has to go under the bridge — unlike First Street, where it’s currently flowing right over the road.
"We have had a close working relationship with the province building up to the peaks," Pulak said. "Now it is not as important because we just need to see how fast it goes down."
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Republished from the Brandon Sun print edition July 15, 2014