Ecotechnological methods for managing non-point source pollution in watersheds, lakes and reservoirs

Abstract

Ecotechnological methods are considered those using technological means for environmental management in a way to minimize the harm to the global environment. Three reasons to use ecotechnological methods are given: they are cheap, minimize the use of raw materials and protect the global environment. In the article the most cost-efficient and environmentally friendly ecotechnologies for non-point source pollution management are given. These are divided into two categories: those done in the watershed and those used within the lake or reservoir. In the first category wetland use, restoration and construction is shown to efficiently reduce different kinds of pollution. The construction of small pre-impoundments is effective for trapping phosphorus as the main cause of eutrophication. In the category of in-lake approaches several are mentioned: biomanipulation or food web manipulation leading to decreased eutrophication, many approaches of mixing and aeration based on recent limnological knowledge, selective withdrawal as a manipulation of outflow and drinking water intake depths in reservoirs, the diversion of polluted inflow waters and sucking of hypolimnion waters. The limitations of the methods are given. Mathematical models helpful in optimizing the use of the corresponding methods are shown.