The leaks are all over the city, in Hochelaga-Maisonneuve, Pointe Aux Trembles, Villeray, Côte-des-Neiges, the Plateau and Verdun.
City officials say increased pressure in the pipes may have lead to multiple breaks and leaks around the city.
Crews were trying to increase water in the reserve because of impending work at the Atwater pumping station.
Jacques-Alain Lavallée, spokesperson for the city, said "these pipes are quite old, and some of them may have little leaks, so when you increase the pressure, automatically, it may, create a bigger leak."
"It make take up to 20 years before we have everything fixed, but for the time being we are on location," he added.
The city has invested a $1-billion in water infrastructure and plans to invest $5-billion over ten years.
A thousand kilometres of pipes need to be repaired or replaced in the city.
Recently, crews have been working on fixing multiple breaks, sinkholes and leaks in Ville-Marie.
Every year, the city has about a thousand breaks of the likes. The city admits the network has been neglected over the years but has been made a priority in the last decade.