To repair a crack in a wall, you first need to drain the water (if needed), then clean the wall, dry it, and patch it up. It is advisable to use a cement mortar with waterproofing properties for repairs. I have found some more effective ways to repair cracks, large and small
Fixing Foundation Cracks that Leak - POM blog. Don't worry, any problem can be fixed. If it does not work out, invite specialists from the POM Group waterproofing company.