Drone flights to provide mapping for Chaline Valley stabilization work
PHOTO BY GREGOR MITCHELL
The first scheduled drone photo run – weather pending – is scheduled for Thursday, April 20, for the Town of St. Lazare to conduct aerial surveillance along the banks of the Quinchien River to determine which slopes and shorelines need landslide reinforcement.
Residents living in Chaline Valley can expect to see a drone flying near their properties for the next three months as St. Lazare begins the preliminary work that will eventually result in the stabilization of the slopes and shorelines along the Quinchien River, said Mayor Robert Grimaudo on Tuesday, April 18.
Grimaudo spoke to Your Local Journal about the drone initiative after the town issued a press release that stated Montreal-based company Drone Box was appointed by the provincial Ministry of Public Security to conduct aerial flights along the banks of the river to collect precise photo and video data of the surrounding area.
More drone mapping in autumn
The drone will fly at 10-day intervals, weather permitting, from mid-April to early June, with the first flight scheduled for April 20 at 8:30 a.m. The flights are designed to operate without disrupting or disturbing human activity and wildlife. Images and videos where people or properties are recognizable will not be used. A second phase of drone data collection will resume in the fall and continue until the actual work to stabilize the shoreline and modify the surrounding slopes begins in late 2017.
The provincial initiative was welcomed by Grimaudo as an indication that both the town and province are committed to rectifying and resolving the landslide situation. On April 3, Soulanges MNA Lucie Charlebois was in St. Lazare to announce a $5.9 million subsidy for the stabilization work from the province. The town will pay the remaining $2.1 million through its surplus fund.
Precise topographic map
The purpose of the drone flights is to regularly collect updated photos and videos along a 1.5 kilometer section of the river and surrounding area so that when the town goes to tender and the stabilization work actually begins, the engineers will have precise information about how the modifications should be done.
“Now that the project is a go, one of the first things they’re going to do is literally create a topographic map of the area,” said Grimaudo. “It will be done in such detail that whatever work has to be done, it will be done precisely. With all the new data that is gathered, we will overlap and cross-reference it with the information we already have.
“When we eventually go out to tender, we will need to produce technical information and we have to provide exact details of what modifications are required for each property. One property may have to have one meter reconfigured whereas another property may need of 1.25 meters of reconfiguration,” added Grimaudo.
The accuracy of the maps will enable the stabilization work to be carried out with surgical precision, added Grimaudo. “We already have the information but now we need to get an exact overview to present to the people who will be doing actual work,” he said.
An estimated 7,000 truckloads of soil will be removed when the 15-week project begins in late December. A similar amount of large stones and rock-fill will be used to shore up the riverbanks to prevent further erosion. Affected homeowners said they’re pleased overall with the joint provincial-municipal intervention when details were presented at a public information session at the end of March.