Links: New data set from city shows free digital maps of Ann Arbor and Washtenaw County

Boundary maps

The most basic of all of the maps is the Ann Arbor city boundary map, which shows the current boundaries of the city. You will note that there is a very ragged edge between the city and surrounding townships, and there are a number of township islands inside the city limits.

Plans under review

The city publishes a feed of Petitions Under Review, showing requests for approval from city departments for construction and development.

From time to time on the agenda of the City of Ann Arbor, Pittsfield Township, Scio Township or Ann Arbor Township you will see annexation requests, which will change municipal boundaries as a result.

School district maps

A third very useful set of county wide maps are boundaries of school districts and townships, seen here combined on one map.

Township islands within the city of Ann Arbor

The irregular boundary of Ann Arbor creates township islands, parcels which have not been annexed to the City in the course of its growth.

What it means for maps to be free

When these maps were originally released, they had a copyright notice on them which restricted them to internal use; that copyright was amended. The school district map detail page says:

"This feature dataclass was created with the intentions of displaying all of the school districts who's boundaries are located within Washtenaw County. The boundaries were created by dissolving the current Washtenaw County parcels layer by the school district field. In order to maintain the attributes of the old school districts file, we then lined up the boundaries from the old school districts map with the dissolved layer. After the boundaries were lined up, topology was created in order to verify that there were no topological errors within the feature dataclass."

Map-making can be hard work; there are a lot of details to get right.