Common Approaches

Below is a listing of common approaches to applied lake management. Each will have it’s time and place, and a combination of these elements may be used. Much more detailed information on lake management can be found in a variety of publications available through the NALMS Bookstore.

For nutrient control

Non-Point Source Management – control of diffuse nutrient sources from the watershed
Point Source Management – control of point sources, usually piped discharges
Hydraulic Controls – diversion, dilution, flushing, and hypolimnetic withdrawal strategies
Phosphorus Inactivation – chemical binding of phosphorus to limit availability
Artificial Circulation and Aeration – mixing and oxygen addition
Dredging – removal of nutrient-laden sediments
Bacterial Additives – encouraging uptake of nutrients by non-algal microbes
Removal of Bottom Feeding Fish – elimination of major recyclers of nutrients

For Plant Control

Drawdown – lowering of the water level to dry and freeze susceptible vegetation, with limited potential to control algal growth
Harvesting – multiple methods of mechanical plant cutting, with or without removal, and algal collection
Biological Control – biomanipulation, the practice of altering biological communities to control algae or macrophytes through biological interactions
Benthic Barriers – placement of materials on the bottom of a lake to cover and impede the growth of macrophytes
Herbicides and Algaecides – introduction of biocidal chemicals to directly kill vascular plants and/or algae
Dyes and Covers – addition of coloring agents or sheet material to inhibit light penetration and reduce vascular plant and algae growths
Dredging – removal of sediment and associated plants to inhibit growth
Sonication – use of sound waves to disrupt and kill algal cells