Ann Arbor's Sylvan Avenue said to be first public street in Michigan using permeable asphalt

Water is poured into an oversized test tube layered with the same kind of material used to construct the new permeable pavement on Sylvan Avenue in Ann Arbor. Water passes almost instantly into the porous asphalt and is caught in a stone reservoir below. The newly paved road was unveiled during a ribbon cutting ceremony on Friday, Aug. 20.

Edward Vielmetti | AnnArbor.com

Sylvan Avenue has been repaved with a new section of porous pavement, designed to better handle stormwater and deal with the problem of persistent damp basements in central Ann Arbor. The permeable asphalt allows rainwater to pass almost instantly through the pavement down into a reservoir of stone — thus, in theory, drastically reducing the chance of flooding or even puddles.

It is believed to be the first street of its kind in the state of Michigan and was unveiled on Friday following a ribbon cutting ceremony and question-and-answer session.

The completion of the repaving project presents an opportunity to look at some history of this short Ann Arbor street.

Where is Sylvan Avenue?

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Sylvan Avenue is a short street that runs between White Street and Packard Street, south of the University of Michigan campus. It is one of two streets that is part of
Assessor's Plat No. 13 (PDF), a neighborhood that was platted October 1930. To its north is Roger's subdivision, which includes Arch Street; to the south is C. H. Cady's subdivision. A common name for the area is the student ghetto, and when that phrase is used in city documents, it's generally perjorative.

Who lives in the area?

When I went to visit the ribbon cutting and open house and walked down the street, I saw a mix of undergraduate students, graduate students, long time city residents and a parent with young children. A late night walk down an adjacent street let me overhear some young adults noisily enjoying adult beverages.

Several houses on the street were rentals, but I don't have a complete list; at least one was for sale.

Who used to live there?

Sylvan Avenue residents in 1917 included the candy manufacturingÂ Hoffman Brothers, Arthur W. and Dudley Hoffman, who lived at 909 Sylvan. Their neighbor was John S. Drake, a motorman for the Detroit United Railway. In 1917 there were four homes on the street, but the plat map of 1930 shows 29 parcels on the street, with lot sizes as small as 2,700 square feet, or having a dimension of 40 feet by 68 feet.

In 1917 the Detroit United Railway operated streetcar lines including a line down Packard. AÂ 1910 railroad history timeline shows the state of the rail system then; not too far away was the interurban station at the corner of State and Packard, a convenience place to commute to if you were a motorman.

When was the street built?

Part of the reconstruction of Sylvan Avenue, and the part that took extra time, involved getting a new gas main put in. The line dates from the 1920s and was replaced before the new street that was unveiled Friday was put in.

The 1917 directory shows homes in the 900 block but not the 800 block of Sylvan.

Why was the street rebuilt?

Sylvan Avenue has been subject to flooding. Homeowners have sump pumps and prior to being rebuilt, the street didn't drain very well. There was ponding and standing water in the street regularly. When it came time to resurface, the decision was made to rebuild it entirely.

In April, coverage of the cityÂ council meeting that approved the reconstruction said:

â€¢ Resolution to award a $343,875 construction contract to ABC Paving Co. for the Sylvan Avenue Permeable Pavement Project, which consists of the reconstruction of Sylvan Avenue, a 20-foot-wide, 800-foot-long residential street running between Packard and White streets.

What does the new pavement look like?

Think of it like a layered cake.

At the top of the street, you have a layer of three inches or so of permeable asphalt, described as the structure and consistency of "Rice Krispies treats" at the top. Below that layer, there's a section of clean crushed stone, then a section of clean smooth stone, and below that a layer of sand.

Unlike the Downtown Development Authority lot, located at the corner of South Fifth Avenue and East William Street, this project uses a permeable asphalt layer which has a polymer in it to make it more permanent and less subject to surface wear than the DDA lot.

What kind of skateboard wheels to use when skateboarding down this street?

If you were to get a permit for a block party to block off this block, you could skateboard down it without violating the city's skateboarding ordinance. If you were to do this, Ann Arbor Skatepark Action Committee member Trevor Staples recommends "big, soft wheels."