Author(s): J. Imberger; J. Antenucci; L. Bruce; A. Ducas; T. Ewing; S. Feaver; M. Hipsey; A. Imerito; C. Lam; S. Morillo; J. Romero; K. Shimizu
Keywords: No Keywords
Abstract: With the great advances in process understanding, sensor and instrumentation technology and modelling capability it is important to ask what if any practical benefits can the lake manager and operator look forward to. Here, we examine some of the more important problems facing operators of drinking reservoirs, hydro-lakes and lakes used predominantly for recreation and the environment. In drinking reservoirs the main problems originate from increased loadings of nutrients leading to increased biomass and biomass that may give rise to toxins, of anthropogenic chemicals such as metals and synthetic organics and of pathogens of different types. Hydro-lakes are predominantly plagued by problems arising from low oxygen levels in the hypolimnion and in recreational and environmentally sensitive lakes the biggest challenge for the operator is to maintain an existing or establish a new trophic hierarchy or protect the water body from foreign species. The control variables that are at an operator' s disposal are the choice of lake water level, the modification of the water column stratification via a de-stratification system, the modification of the lake flow path with flow intervention curtains, intervention in the catchments to modify the loadings flowing into a lake, manipulation of the trophic chain with introduction of new species and chemical dosing, the latter being of marginal use in a large lake. Each of these options is cost effective under certain circumstances. We endeavour to provide a users guide for their application and show how, especially new instrumentation and modelling methodologies may be used to achieve an effective intervention.