Major Watersheds & Floodplains

Major Watersheds of Ozaukee County
A watershed is the land area from which surface runoff drains into a stream channel, lake, reservoir, or other body of water that flows toward a common outlet. For example, in this county, all the creeks and rivers eventually flow into Lake Michigan.

There are 7 WDNR designated watersheds within the county. The largest watershed is the Milwaukee River South, which covers 164 square miles, or 66% of the county. The watersheds and sub watersheds in the county are shown below.

"A watershed is more than the physical landscape that is defined by its ridges with one outlet for water to flow. A watershed supports a variety of resources, uses, activities and values, where everything there is linked in such a way that eventually all things are affected by everything else in the watershed. Perhaps more importantly, a watershed contains the history of all who went before - and the spirit of those who touched it remains." - George Wingate, US Bureau of Land Management
Shoreland & Floodplains in Ozaukee County
Shoreland is areas within 300 feet of the ordinary high water mark of a navigable river or stream and / or within 1,000 feet of the ordinary high water mark of navigable lakes, ponds or flowages.
Shoreland Zoning Diagram
Floodplain is land that has been or may be covered by flood water during a regional flood (i.e. 100 Year Flood). This includes the floodway, flood fringe, shallow depth flooding, flood storage, and coastal plain areas. Floodplains in Ozaukee County encompass an area of approximately 15 square miles, or 6% of the county.
Floodplain Diagram
Shoreland and floodplains are generally not well suited for urban development, because of the flood hazard, the presence of high water tables, and soils poorly suited to urban uses. For planning and regulatory purposes, each city and village administers shoreland and floodplain regulations within its corporate limits, while the county administers these regulations in unincorporated areas.