I planted these 2 Lumnitzera littorea at this site of the Flora Stitches because of the localised waterlogging conditions.
They have grown pretty tall now and flowers very frequently. So it is possible to actually plant mangrove or water loving plants in areas with high water tables etc. In fact, I planted other water loving trees e.g. Sonneratia caseolaris, at similar locations and they are all doing well.
The point is, we do not always have to spend money to solve localised waterlogged issues. One possible solution is just to choose the right plants for the site conditions.