Bayswater vic new railway underpass FAIL

2 years ago, there was an underpass built to get rid of the boom gates on Scoresby road, Bayswater Vic.
Ever since then, despite many calls and complaints, the new drain they installed next to our back fence, floods our yard whenever it rains.
Some guys came out when I first called, and installed an agi pipe along the fence which did nothing.
The water floods out of the drain for hours after it rains and all of it ends up in my back yard. Considering the millions spent on this project, you would think they could afford engineers that would design drains to cope with even minor rainfall.
Had enough.