Fox lake is a small, heavily-developed lake totaling 143 acres and reaching a depth of 24 feet. Approximately 60% (86 acres) of the lake in considered littoral and is less that 15 feet. There are no surface water inlet and the lake received water primarily for stormwater runoff and groundwater interactions. There is one outlet to the lake on the which flows south through a wetland to Lake Sallie.
Between 1966 and 1999, land use around the lake changes drastically with the amount of residential home increasing from 24 to 55, causing increased development pressure in increased nutrient loading and declining water quality. Prior to 2004, a 40-acre parcel just north of the lake was used for ag purposes with turkey manure being applied to the land at times. The lake showed signs of degradation with nuisance algal bloom and poor water clarity. The turkey farm ceased its operation in 2004 and along with that, it application of manure to the property. That lake responded favorable with drastic and immediate increases in water clarity and reductions of in-lake phosphorus levels. Currently, water quality is good with an increasing trend is clarity with a 14-foot average over the land ten years and a stable phosphorus concentration of 12ppb over the same period.
Dramatic changes in land use, including updated septic systems and restoration of the agricultural land to native vegetation between 2002 and 2006 led to sharp increases in water clarity and quality. Currently, the predominant land use is forested and grassland, which accounts for 74.8% of the land use in the lake drainage area. 13% of the land is used for cultivated crops and 10% has been developed.
Water quality in 2016 was similar to what was observed during the previous sampling cycle, in 2012, and has been maintained better than average for both clarity and chemistry. Summer water clarity average was recorded at 14.1 feet, a 2.8-foot increase over average. Fox Lake remained well mixed throughout the summer, with bottom temperatures always with 4°F of the surface temperatures. Oxygen level were also very well mixed throughout the water column.
The effects of the heavy July and August rains had a much smaller effect on Fox Lake than other area lakes. Causes for this could include the presence of the natural shoreline buffer around the lake that helps reduce stormwater runoff and should be protected whenever possible.