Eutrophication of lakes and reservoirs is enrichment with plant nutrients, mainly phosphorus and nitrogen, which enter as solutes and bound to organic and inorganic particles. Enhanced growth and increased abundance of aquatic plants often results in reductions in water quality. Augmented nutrient inputs to inland waters usually result from modifications of watersheds, such as deforestation, agricultural and industrial development and urbanization. Environmental conditions within the bodies of water and in the airshed and watershed all influence eutrophication. Factors within lakes that modulate impacts of nutrient enrichment include food web structure, exchanges between sediments and water, the shape of the basin and movements of water within the lake or reservoir. Climatic and hydrologic conditions in the watershed further alter impacts of eutrophication.