Clouds to blame for faulty government flood maps, Quebec mayor says

To find the problem with the Quebec government's new flood maps,look up.

Clouds.

The government neglectedto correct areas on the map obscuredby the shadows cast by cloudy skies, according toVaudreuil-Dorion Mayor Guy Pilon.

Hundreds of angry residents packed a meeting hallin Vaudreuil-DorionThursday evening, demanding government officials explainwhy their homes were nowincluded in a flood zone, despite being several metresabove the high water level.

"OK, do you want to hear a good one?" Pilon asked CBC Montreal Daybreak host Ainslie MacLellan Friday, before embarking on his explanation.

Pilon said the provincial government was too hasty in creating new zero-to-20-year flood maps.

Municipalities have flood-zonemaps already, but many are considered outdated.The governmentwanted to actquickly to release the new maps, he said, so that after this spring's flooding, building permits would not be issued to homeowners whose properties areinside flood zones.

The new mapsshowareas ostensibly at risk offlooding, designated as"special intervention zones," or zonesd'intervention spciales(ZIS), where construction and rebuilding wouldbe put on hold.

• Quebec won't permit reconstruction of worst-hit homes in flood zones

Those ZIS includeareas that were flooded in 2017 or 2019, as well as those now deemed to be at elevated risk of flooding, based on satellite imagery.

Property owners in those ZISwill no longer be allowed to build or rebuild their homes, and renovations willonly be allowed if the total cost of those renovations comes to less than 50 per cent of the property value.

'Really, really amateur'

Pilon said there is a reason so many homeowners had been stunned to find their properties listed as within a ZIS, even though they have not been flooded.

The mapmakers"forgot to remove what they call the 'shadow zone,'" Pilon said, referring to clouds. Satellite imagery can be misled by clouds, he explained, and corrections often have to be madeby land surveyors, working on the ground,the old-fashioned way.

'Amateur' map-making caused panic, says mayor

Pilon said municipalities could have provided data that would have filled in the blanks.

"They decided to go with the machine and to work like amateurs really, really amateur and to make thousands and thousands of people panic," he said.

In Vaudreuil-Dorion, Pilon said, about 30 homes were flooded in the 2017 and 2019 floods. But the new zone defined by the government's study included 1,500 homes in hismunicipality alone.

The new maps cover812 municipalities across Quebec and, just like in Vaudreuil-Dorion,hundreds more homeowners in other municipalities, as well, find themselves unexpectedly to be included in flood zones.

Sainte-Marthe-sur-le-Lac, where more than 1,000homes were flooded in April when the Lake of Two Mountains breached a dike,has been exempted from the limits on repairsbecause of whatMunicipal Affairs and Housing Minister AndreLaforestcalled the "exceptional" circumstances of that flood.

Laforestsays she wants to reassure Quebecersthat adjustments will be made to the new maps.