Lakes that are large (>10 acres), shallow (<18 feet), soft (alkalinity < 50 ppm), and seepage have no inlet and outlet, and the main water source is from precipitation or runoff.
Like their deep counterparts, the submergent community of soft water shallow seepage lakes is characterized by a group of slow-growing, mostly rosette-forming aquatic plants called isoetids. These plants cannot utilize bicarbonate as a source of carbon and instead assimilate inorganic carbon from the sediment via an extensive root system. Typical species include seven-angled pipe-wort (Eriocaulon aquaticum), quillworts (Isoetes spp.), and dwarf water-milfoil (Myriophyllum tenellum). However, their short stature makes them vulnerable to shading, and as a plant community, it is extremely sensitive to nutrient pollution that favors faster-growing submerged and/or floating-leaf species. The floating-leaved community consists largely of water-shield (Brasenia schreberi) but also includes floating lilies (Nymphaea odorata and Nuphar variegata). Associated fish species include bluegill, pumpkinseed, and largemouth bass.
