Seasonal limnological changes in the vicinity of a major (120 acres) recreational facility on Lake Sidney Lanier, Georgia were studied. During the study period only the beginning phases of construction occurred (clearing and grading land, road construction and utility installation). Parameters measured included: temperature, dissolved oxygen, pH, Secchi disk transparency, and iron and nitrate concentrations. A positive heterograde oxygen profile developed during summer stratification. The lake water contained the nutrients necessary for the production of oxygen. However, they were not washed into the lake from the construction site. Lake Lanier could be caused to become eutrophic in a rather short period of time if the influent waters are allowed to be degraded by man-made wastes.