If the water quality cannot ...
Published by Francois Van Wyk, Water Quality Specialist at Rand Water
If the water quality cannot be improved I suggest the following: aerial spraying to kill most of the plants - just so you can get ahead. Remove dead plants as much as possible or the decomposing matter will cause more problems, although this will be "once -off". Thereafter you will have to have a permanent physical removal program, which is labour intensive but is the most effective. The weevils are also very effective but takes a lot longer to make a significant impact.