In recent years, samples have been collected from five locations in Houghton Lake to evaluate baseline water quality conditions. When evaluating water quality, the nutrient "phosphorus" is of primary concern in that phosphorus is the nutrient that most often stimulates aquatic plant growth and leads to a number of problems collectively known as eutrophication. The median phosphorus concentration measured to date in Houghton Lake is just above the eutrophic concentration of 20 parts per billion.
During ice-free periods, Houghton Lake is well mixed and temperatures in the lake are nearly uniform top to bottom. Oxygen is mixed throughout the water column and fish and other aquatic organisms are able to inhabit the entire water column. Algae growth in the open waters of the lake is minimal, however, transparency measurements are generally less than 10 feet. The low transparency is likely due to the mixing of the water column that suspends sediments, and the presence of natural tannins draining from area wetlands that impart a brownish color to the lake.
Oligotrophic lakes are generally deep and clear with little aquatic plant growth. These lakes maintain sufficient dissolved oxygen in the cool, deep bottom waters during late summer to support cold water fish such as trout and whitefish.
Lakes that fall between the two extremes of oligotrophic and eutrophic are called Mesotrophic lakes.
Eutrophic lakes have poor clarity, and support abundant aquatic plant growth. In deep eutrophic lakes, the cool bottom waters usually contain little or no dissolved oxygen. Therefore, these lakes can only support warm water fish such as bass and pike.
Recent sampling indicates that Houghton Lake’s water quality is between mesotrophic and eutrophic.