Lake Rehabilitation Options for the Machado Lake Ecosystem Rehabilitation Project

Eutrophication of Machado Lake, including the accumulation of toxic sediment, has degraded habitat, damaged water quality, reduced aesthetic value, and reduced the attractiveness for recreation. Machado Lake has deteriorated through excessive external and internal loading of nutrients, sediment, and trash. The Machado Lake Ecosystem Rehabilitation Project involves evaluation of lake rehabilitation options to improve the water quality conditions, aesthetic value, and the biological diversity of the ecosystem to attain and sustain desired uses/characteristics, and to create a healthy lake. Options considered appropriate to Machado Lake include sediment removal, supplemental water addition, off-line treatment wetland, oxygenation, phosphorus treatment, aquatic plant management and littoral zone enhancement, shoreline stabilization, floating islands, selected stormwater best management practices, in-lake sediment basins, and baseflow treatment. These options are predicted by the Lake Water Quality Model to reduce phosphorus concentrations in the lake by 85 percent, nitrogen concentrations by 34 percent, and chlorophyll-a by 77 percent.