Our environment, like ourselves, is dependent on groundwater. This dependency is reflected in our flowing rivers and streams, as well as our lakes, ponds, and wetlands. Some natural communities, such as northern white cedar swamps and fens, require a constant influx of groundwater.
In addition to the volume of groundwater supplied, the chemical and physical characteristics of groundwater can define specific communities. Since groundwater is constantly in contact with rock units, minerals associated with the rock influence the chemistry of groundwater. Most northern white cedar swamps require calcium-enriched groundwater to exist. The pH of fens is usually neutral, or even slightly alkaline, due to the presence of dissolved calcium.
Favored fish spawning grounds have been identified in stream sections where there is an upwelling of groundwater through clean sand and gravel. For instance, trout actively seek out groundwater upwelling zones for spawning. Groundwater flushes fine sediment from the stream bed in these zones and removes metabolic wastes produced by embryos.
The temperature of groundwater remains relatively stable year round. During the winter months, portions of water bodies are kept from freezing due to the higher temperature of groundwater. In the summer, groundwater replenishes streams, rivers, and ponds with cold water. Fish habitat benefits from groundwater input in both seasons.
Contamination of groundwater can disturb the delicate chemical balance of natural communities and destroy drinking water supplies. An awareness of the multiple functions of groundwater serves as a first step toward long-term protection of this resource.