Physical and mechanical treatments can often be the simplest and very effective, but also are time consuming and can require a lot of physical effort. This can be done with a rake or shovel or your bare hands. This technique works well near the shoreline and in shallow areas and works great at removing the weeds. This is also a good maintenance technique. You can selectively remove individual plants to keep them from overrunning your pond. Desired species can be held in check with selective harvesting before they become an undesirable species.
There is also harvesting equipment available that can remove more weeds in less time and is also more effective in slightly deeper water where hand removal is difficult, still only effective in the 6' range. This method is also much less selective than hand removal. This equipment varies in size and scale. Some is available for individual use in small ponds, other are large barges that harvest the plants with cutters, conveyors, and a large platform to store them.
Either way you physically or mechanically remove the plants, you must make sure to remove all the plant fragments from the pond. Many of the aquatic plant species can re-root and grow from small segments. Therefore, cutting, but leaving fragments behind, will lead to more growth in the future and the plants can spread into a larger area of the pond. It is also important to remove the plants away from the pond far enough to prevent them from washing in or getting blown back in. Physically removing the plants is a great way to remove large amounts of nutrients as well, which will improve overall pond health in the future.