Door county’s Impervious Surfaces

Door County has seen a lot of development in the last 30 years, but impervious surface data compiled by Door County GIS Mapping Specialist Audrey Forslund shows that in some communities there’s more green space left than you might expect (and others much less).

Forslund said gathering the data on the area covered by impenetrable materials such as asphalt, concrete, brick and stone was tedious. She used aerial photos taken in 2009 and calculated the total surface covered by structure, roads, sidewalks, driveways and other non-porous materials. She said it’s by no means exact – it’s not always clear that a surface is impervious – but it is in the ballpark.

Door County Planning Department head Mariah Goode said the information will be input into the county’s Greenprint website (, which can be accessed by developers, residents and county planners to provide detailed information about properties. It could also help the Door County Soil and Water Department to understand and handle storm water runoff problems in various communities.

Source: Door County Planning Department