Flow Measurement Campaign in the Sanitary Sewer Network in Brossard

The City of Brossard initially aimed to conduct continuous flow measurement in 25 sanitary sewer pipes. The project was divided into two phases:

• Phase I : lasted 4 weeks during the spring snowmelt and high groundwater period.

• Phase II :lasted between 6 and 10 weeks during the summer low and medium groundwater period, including both dry weather and rainfall events.

Our technicians carried out the installation and launch of Phase I flow measurements at 26 sites on April 4, for a period of 4 weeks (removal on May 3, 2019). Phase II measurements were installed at 24 sites on July 18 for a continuous 6-week period. An additional week with heavy rainfall was added (removal on September 5, 2019).

Additionally, our technicians installed four rain gauges during each phase of the project. A preliminary report was issued weekly, and a final report was delivered at the end of 2019.

For most sewer pipes, high water flow allowed the use of conventional Doppler H/V sensors during Phase I.During the summer phase, low-flow conditions required the use of secondary measuring elements such as flumes or thin-plate weirs at some sites to improve data accuracy.
The addition of primary elements improved the reliability of measurements under low-flow conditions.

It is worth noting that one additional site was added in Phase I to account for the need to measure two separate sewer pipes at a single manhole. This addition was done at no extra cost, compensating for the cancellation of one planned site in Phase II.