A Natural Process
Flooding is a regular, natural process. It occurs on every river, large and small, in urbanized streams and cold water creeks. Failure of levees and dams and inadequate drainage in urban areas can also result in flooding. On average, floods kill about 140 people each year and cause $6 billion in property damage.

Frequently Asked Questions
What are the physical properties of Ozaukee County?
Ozaukee County has the smallest total land area by county in the State of Wisconsin, covering approximately 609 kilometers squared. The county is located in the southeastern corner of Wisconsin, along 45 kilometers of western Lake Michigan shoreline.

Elevation ranges from 177 to 294 meters above sea level, and except for a few isolated spots where dolomite bedrock is exposed at the surface, the entire county is covered with glacial deposits ranging from large boulders to fine-grained clays. Soils are generally classified as: “silty clay loam till”, “loam to clay loam”, and “organic mucky peat” (Parker, et al. 1970).

There is an east-west variation in temperature and precipitation in Ozaukee County due to the presence of Lake Michigan, with average monthly temperatures ranging from –7.1 to 20.7 degrees Celsius and precipitation and snowfall averaging 77 and 93 centimeters per year respectively (NRCS WETS Station 1999). Current land use is variable and includes: residential, commercial, industrial, agricultural, wetlands, woodlands, and unused rural/open lands. The amount of land in Ozaukee County devoted to urban land uses has increased by 170% since 1963 (SEWRPC 1997).

What kinds of water resources are in Ozaukee County?
Surface water resources in the county include approximately 250 kilometers of rivers, streams, and creeks, all of which eventually flow into Lake Michigan . The entire eastern side of the county is bounded by approximately 45 kilometers of Lake Michigan shoreline. The streams are geologically young (established after the last glaciation), and as a result of inefficient drainage, many marshes, wetlands, bogs, and small lakes are also present in the county landscape.

The local groundwater table for most areas in the county is generally shallow, located in the unconsolidated glacial deposits at depths of less than 25 and 50 feet. The deeper groundwater sources in the county are present in the dolomite and sandstone bedrock layers, which generally flow east toward Lake Michigan .

Where does my drinking water come from?

Drinking water sources in the county are divided into public and private water supply systems. Floodplain maps shows portions of the county served by public water utilities and private water supply systems. About ½ of the county population is currently served by public water utilities that obtain water from surface and groundwater sources.

Most of the public water utilities in the county are supplied by groundwater, while the City of Port Washington and portions of Mequon are supplied by Lake Michigan water. A few private water supply systems in the county include groundwater wells that serve residential subdivisions, apartment or condominium developments, and institutions. The remaining water supply systems in the county, typically present in suburban density single-family residential developments or agricultural areas, are private groundwater wells.

What are floodplains and shorelands?
The floodplains of a river are the wide, gently sloping areas usually lying on both sides of a river or stream channel. The flow of a river onto its floodplain is a normal phenomenon, and in the absence of flood control works, can be expected to occur periodically. For planning and regulatory purposes, floodplains are defined as those areas subject to inundation by the 100-Year recurrence interval flood event.

This event has a 1% chance of being equaled or exceeded in any given year. 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.

are defined by the Wisconsin Statutes as lands within the following distances from the ordinary high water mark of navigable waters: 1000 feet from a lake, pond, or flowage; and 300 feet from a river or stream, or to the landward side of the floodplain, whichever distance is greater. The floodplains shown on floodplain maps encompass an area of approximately 15 square miles, or 6% of the planning

My house isn't near a creek, why should I have to pay for flood protection?
Rain that falls on open ground is either absorbed or flows into creeks and rivers. Rain that falls on houses, sidewalks, buildings, parking lots and streets runs off into storm drains, and then flows into the creeks and rivers. In this way, every urban and suburban structure, whether near a creek or miles away, contributes to the amount of water flowing in our local waterways. And during heavy rains, flood management projects protect our streets and highways, schools, shopping centers, parks and the places we work from the danger of flooding and the damage and inconvenience that flooding could bring to every county resident.

What are Greenseams?
Greenseams is an innovative, flood management program that permanently protects key lands containing, water absorbing soils. The program also aims to preserve land along stream corridors that connects the region’s supply of public properties. A national non-profit conservation organization, The Conservation Fund (TCF), runs Greenseams for the Milwaukee Metropolitan Sewerage District (MMSD), contact MMSD for more information.

What are conservation buffers?

Conservation buffers are small areas or strips of land that are strategically placed in the agricultural landscape to intercept pollutants and manage other environmental concerns. These buffers can also enhance fish and wildlife habitat and reduce flooding concerns. Financial incentives for establishing and maintaining these buffers are available through several USDA conservation programs.

Where can I find more local information?
Land and Water Department

Administration Center
121 W. Main St.
Port Washington , Wisconsin 53074-0994

Ph: 262-284-8270