While in some areas, farming methods and wastewater treatment systems have been upgraded, waters with existing high nutrient levels will be slow to recover. Engineering designs of water conveyance systems, dams, and impoundments can also serve to avoid some future aquatic vegetation problems, however, costs and deadlines may prohibit the incorporation of these innovative measures. Four general approaches have been used to control aquatic vegetation problems. At times, a combination of these methods into an integrated pest management scheme has proven useful. Each approach has its advantages and disadvantages.
Mechanical control involves cutting and removal of the vegetation from the waterway.
Various dredges, cutters, and conveying equipment have been developed for this task. In some areas, certain harvested aquatic vegetation has been put to use as mulch or animal feed. However, as can be expected, mechanical removal is a cumbersome task requiring expensive, slow-moving equipment, high maintenance costs, and considerable energy expenditures. Re-growth may occur rapidly and such equipment is not adaptable to all types of waterway systems. Biological control involves the introduction of natural control agents such as herbivorous fish, insects, or plant pathogens, which feed or host upon nuisance vegetation.