In the big picture, water quality was great in 1932, poor in 1972, better in 1983, and stayed the same or a little better now. The simplest way of looking at water quality is through the clarity of the water itself. Water clarity in lakes is primarily affected by phytoplankton and tiny suspended soil particles, including clay. The simple way of measuring this is with a 6” inch black and white disk called a secchi disk. This disk is lowered into the water on a sunny day to a depth at which it can no longer be seen. This is known as the secchi depth.

The slow improvement in the clarity of Saratoga Lake is illustrated in the graphic below. The positive impacts of the sewage diversion were also clearly shown by dramatic decreases in the levels of total phosphorus. Following the diversion of sewage, a 50% decrease in the levels of total phosphorus has occurred in between the 1974 to 1984 sampling results.

Since that reduction, total phosphorus has remained stable in the Saratoga Lake. The 1984 fall total phosphorus concentration was 0.020 mg/l, as was the average fall total phosphorus during 1993-1996. This reinforces the observation made with the secchi disk that little has changed from since1984.

The stability of the water clarity and phosphorus levels needs to be re-evaluated as part of the watershed management plan. Is this as good as the water quality gets? The answer is, we don’t know. To the person boating on the lake getting stuck in weeds, the answer is simply yes, it needs to be better. The history of the lake shows that it was better at one point.

At this time, competing forces may interfere with continued lake water quality improvement. The competing forces include continued milfoil growth and expansion, zebra mussels which feed on algae causing increase in water clarity, possible diversion of lake water for municipal supply, conversion of camps to year-round homes, and new development in the watershed. The watershed community, as a whole, needs to decide how much it is willing to contribute towards the improvement of the water quality of Saratoga Lake.