Lakes that are large (>10 acres), deep (> 18 feet), hard (alkalinity > 50 ppm), and seepage have no inlet and outlet, and the main water source is from precipitation or runoff.
The macroalgaes muskgrass (Chara spp.) and stonewort (Nitella spp.) are frequent members of the submergent community of this lake type, with stoneworts often preferring deeper waters. Common aquatic vascular plants in undisturbed deep seepage lakes include naiads (Najas spp.) and a variety of pondweeds, including large-leaf pondweed (Potamogeton amplifolius), variable-leaf pondweed (P. gramineus), and flat-stem pondweed (P. zosteriformis). Where nutrient levels are high, water-milfoil (Myriophyllum spp.), coon-tail (Ceratophyllum demersum), and common waterweed (Elodea canadensis) are more abundant. Floating lilies (Nymphaea odorata and Nuphar variegata) often occur in shallow waters. Associated fish species include mimic shiner, blunt-nose minnow, rock bass, bluegill, pumpkinseed, smallmouth bass, largemouth bass, black crappie, yellow perch, and cisco and mottled sculpin in very deep lakes.
