The City of Marinette planning area contains a variety of natural resources. The natural resource base of the planning area is the primary determinant of its development potential and ability to provide a pleasant and habitable environment. The principal elements of the natural resource base are climate, topography, geology, soils and natural areas, including woodlands, wetlands and water resources. Knowledge and recognition of these elements and their interrelationships are essential so that human use and alteration of the natural environment does not advance to the detriment of nonrenewable or slowly renewable resources.

The city of Marinette planning area is a mix of predominantly wooded areas with scattered agricultural lands surrounding the city to the south and west. The planning area has many natural amenities including the Menominee River and the bay of Green Bay, along with numerous tributaries, woodlands, approximately 6,627 acres of wetlands, and various archeological sites. Much of the Marinette planning area outside the city relies on a good groundwater source to provide its residents with safe drinkable water.

Marinette's 1985 Sanitary Sewer Service Plan identifies that this plan will be updated every five years in order to address changing conditions within the area. Though the city of Marinette has not experienced an increase in population, the adjacent towns of Peshtigo and Porterfield are experiencing rapid population growth and are projected to increase their populations through an increase in residential developments. These developments are occurring along the periphery of the city of Marinette and along the Lake Michigan/Green Bay coastline. The towns of Peshtigo and Porterfield both have high numbers of wetlands within their municipal limits. Future infringement on these wetlands is likely and should be controlled in order to allow the wetland's ecosystems to function and help recharge the area's groundwater. Existing and future developments with private on-site wastewater treatment systems may experience system failures and the city of Marinette would then be pressured into extending sanitary sewer to alleviate these septic problems. In the event that sewer lines are extended, further development along sewer mains may occur. It is the goal of the Marinette Areawide Sewer Service Plan Update to protect local water quality and provide the necessary guidance on the location of future development within the study area.