Environmental groups say more needs to be done after the Lachine Canal was forced to be closed twice last week.  

Heavy rain forced the temporary closure of the canal.

Storms can cause Montreal's sewer system to overflow straight into the canal.

When that occurs, Parks Canada closes the locks, and shuts down all recreational activity due to bacterial contamination.

The canal has now reopened, but Green Party Deputy Leader Daniel Green said it's time to fix the problem for good.

“Sometimes Parks Canada doesn't shut down the canal fast enough, and that's what happened last week.  People had access, there was no signage to tell the Lachine Canal was polluted, so that has to be resolved, and we're having a very wet summer, a hot summer and bacteria love hot wet weather,” said Green.

The city said it's building retention basins to prevent the overflow of sewage into the canal.

The work is set to be completed in 2017.