Column: Digital Information Flood

Ann Arbor city council Feb. 21 preview: flood maps and demolition

At the city council’s Jan. 23, 2012 meeting, Dan Rainey – the city of Ann Arbor’s head of information technology – was on hand to receive an award recognizing the city’s use of digital technology. The award was for 5th place in the 2011 edition of the Center for Digital Government’s Digital Cities Survey.

Parcel Flood

Screenshot from the city of Ann Arbor and Washtenaw County mapping website. It shows the new floodway and floodplain boundaries for the new FEMA maps, highlighting the buildings and parcels that are no longer in the floodplain, according to the new maps. The parcel with extra highlighting (yellowish green) is one of special interest for this column.

Yet among the nearly 12,000 words in The Chronicle’s report from that meeting, there’s no mention of the city’s Digital Cities award. The decision not to include that award in the meeting report was not one about which I agonized; it was not made on the basis of some high-minded journalistic principle. From a purely practical point of view, the award was likely a victim of my finite stamina for writing about a city council meeting.

But one reason I don’t mind omitting that kind of award from a meeting report is that it really does not matter to me where Ann Arbor ranks on that survey. What matters to me is the fact that the city’s investments in the realm of digital technology make life in Ann Arbor as a local journalist easier than it would be otherwise.

And that, I think, is best illustrated with a specific example. It’s an example I stumbled across a couple of months ago. But because it overlaps with two agenda items on the city council’s next meeting, on Feb. 21, I thought now would be a good time to share it with readers. One of those agenda items involves demolishing derelict houses, and the other involves the Federal Emergency Management Agency (FEMA) flood maps.

This tale begins on Facebook and ends in the bucket of a big yellow backhoe.

City Council Agenda: Feb. 21, 2012

First, let’s preview two agenda items related to the big yellow backhoe. The city council’s Tuesday, Feb. 21, 2012 agenda, like all upcoming meeting agendas, is available online through the Legistar system. The regular meeting schedule for the council calls for meetings to start at 7 p.m. on the first and third Monday of the month. But this week was a holiday, Presidents Day, and the meeting day shifted to accommodate it.

Live streaming of the meetings is available online via CTN’s channel 16. Depending on your connection, you’ll experience a delay of 3-5 seconds after the page loads before the video begins streaming.

City Council Agenda: Flood Maps

On Tuesday’s agenda is consideration of an ordinance change that will adopt new flood maps.

By way of background on those maps, the National Flood Insurance Program (NFIP) makes flood insurance available for properties in participating communities – Ann Arbor is a participant. If a building has a federally-backed mortgage and it’s located within the “1% annual change floodplain” (previously called the “100-year floodplain”) then flood insurance is required.

Ann Arbor’s most recent Flood Insurance Rate Map (FIRM) dates from Jan. 2, 1992. In 2004, the Federal Emergency Management Agency (FEMA) began a map revision process for Washtenaw County. Various drains in the city were re-analyzed, using updated data, and on July 27, 2007, FEMA issued preliminary maps. After the required public review, appeal and revisions, on Oct. 3, 2011, FEMA issued a letter with a final determination, indicating that the new maps would be become effective on April 3, 2012. [.pdf of Oct. 3, 2011 letter] [.pdf of Dec. 20, 2011 reminder letter]

Compared to the previous 1992 maps, 321 parcels are no longer analyzed as lying within a floodplain. However 116 parcels that were previously not analyzed as in a floodplain are now in a floodplain, according to the new maps. Building-wise, 452 structures are no longer analyzed as lying within a floodplain, while 88 buildings are now in a floodplain, according to the new maps. Watershed-by-watershed, here’s the breakdown.

Parcels Into Floodplain        Parcels Out of Floodplain      

Allen Creek      45            Allen Creek      199
Huron River       5            Huron River        9
Mallets Creek    24            Mallets Creek     10
Millers Creek    16            Millers Creek      0
Swift Run        11            Swift Run         84
Traver Creek     15            Traver Creek      19
Total           116            Total            321

Buildings Into Floodplain      Buildings Out of Floodplain      

Allen Creek      46            Allen Creek      204
Huron River       5            Huron River        6
Mallets Creek    23            Mallets Creek     48
Millers Creek     3            Millers Creek      0
Swift Run         2            Swift Run        171
Traver Creek      9            Traver Creek      23
Total            88            Total            452

The council will be asked on Feb. 21 to give initial approval to a change to the city’s building code to specify the zones in the new maps as flood-prone areas. The entire city code set is available online through the city clerk’s gateway. (Scroll to the bottom of the page, past the privacy policy.)

As an ordinance change, the council is required by city charter to give an initial approval (first reading) followed by a final approval at a subsequent meeting.

City Council Agenda: Demolition Fund

The second agenda item of interest for this tale is one that establishes a $250,000 allocation for the demolition of buildings that the city deems dangerous under Chapter 101 of the city code. The city would like to target buildings that are diminishing the quality of neighborhoods, dragging down property values and attracting nuisances. The appropriation is from the city’s general fund, and thus requires an 8-vote majority. The city expects to be able to reimburse the general fund from the proceeds of a lawsuit settlement related to the old Michigan Inn property on Jackson Avenue.

The issue of dealing with abandoned and derelict buildings is one that has been pushed by Ward 3 councilmember Stephen Kunselman. By way of example, at the council’s May 16, 2011 meeting, Kunselman questioned the prioritization of neighborhood stabilization funds for the demolition of three houses on the site for the proposed Near North affordable housing development (on North Main Street, south of Summit). [No demolitions have yet taken place.] From The Chronicle’s meeting report:

Kunselman noted there are lots of blighted properties in the city that could use these funds. Why were these houses on North Main selected and not others? Why wouldn’t the developer be responsible for tearing down the houses? [Mary Jo] Callan told Kunselman those were great questions. The funds have a time limit on them, so part of the reason to use them on the Near North demolitions is that it’s a project ready to go, there’s a clear owner, a clear title, and there are no potential delays. In addition, NSP funds can only be used on certain census tracts.

Kunselman wanted to know if a lien would be placed on the property and how the Near North developer would pay it back. Callan said that certain liens are forgiven. But if the property were sold, it would have to get paid back. Kunselman concluded from what Callan said that the money for demolition is a grant. Callan told him, “It’s an investment in permanently affordable housing.” The expectation is that the housing will be permanently affordable. The city’s strategy is not heavily weighted towards “recycling” the money, as Kunselman was suggesting: use money for demolition; place a lien on the property; the property sells; the lien is paid back; and the money becomes available for demolition of another blighted property.

Kunselman asked community services area administrator Sumedh Bahl how many blighted properties the city’s nuisance committee had identified. Bahl said the committee is prioritizing a list and in the next few months, that list would be shared with the council. Kunselman wondered if the city would have any money to undertake demolitions. There was a house torn down in his neighborhood where the money was paid back. Was there any way to make sure the North Main property owner does pay it back?

And it was Kunselman who was responsible for the origin of this column – in a Facebook comment he left about a link pushed out on The Chronicle’s Facebook network.

Ann Arbor Housing Commission

On Jan. 6, 2012, The Chronicle published an article based on a meeting of the Ann Arbor Housing Commission board. Newly-hired executive director Jennifer L. Hall described for the board a possible plan for the acquisition of additional property. The location of the property was not disclosed – it was discussed in a closed session with the board. Discussion of land acquisition is an allowable use of closed sessions under Michigan’s Open Meetings Act.

Kunselman Facebook Comment AAHC

Kunselman's Facebook comment about The Chronicle's reporting on the possible acquisition of additional property by the Ann Arbor Housing Commission.

Kunselman wrote on a Facebook post containing a link to the article: ”The last time the AAHC bought land, the city became the owner of a blighted house that had to be torn down after years of sitting empty.”

Following up with Kunselman, he described the general location as being on Platt Road, north of Verle.

From there, I checked out the maps available online through the joint city/county geographic information service. I clicked around on likely-looking parcels using the “point identify” tool.


Satellite image of 3432 Platt Road from 2010.

It’s a tool that displays information about whatever parcel a user clicks on. I was able to identify 3432 Platt as a parcel owned by the city of Ann Arbor. And by adding the satellite imagery to the layers I was viewing, I was able to verify that there was no building on the property. Checking with Kunselman, he verified that this was the parcel he had in mind.

Kunselman also subsequently mentioned to me that one of the issues associated with the property was its location in a floodplain.

By searching the city council minutes on Legistar for “3432 Platt,” I was able to verify the history of the parcel as described by Kunselman. From the Oct. 7, 1996 minutes:

Whereas, The Ann Arbor Housing Commission purchased the property at 3432 Platt Road (parcels A, B, C, D) on January 30, 1992 for the amount of $99,500.00 to be used for the new development project with property’s owner identified as the City of Ann Arbor acting by and through the Ann Arbor Housing …

Whereas, After the purchases were completed, it was determined that portions of the properties are in the 100-year flood plain and HUD determined that it would not give final approval for these properties nor reimburse the Housing Commission for the purchase price of the properties;

Whereas, Efforts by the Housing Commission to sell these properties have been unsuccessful;

Whereas, The Housing Commission is now asking that the properties be conveyed back to the City in exchange for a reduction of the debt owed by the Housing Commission to the City; and Whereas, The Housing Policy Board at its meeting on June 19, 1996, recommended that the City take title of the Platt Road properties from the Housing Commission and credit the debt owed on the properties;

RESOLVED, That City Council approve the transfer of the above described properties from the Ann Arbor Housing Commission to the City of Ann Arbor; …

Three years after that, on May 3, 1999, the council passed a resolution authorizing the disposal of the property as “excess city property.”

What’s happened since 1999? A Google search confined to just the city’s website turned up the city’s 2007 flood mitigation plan. In that plan, various options are presented for the parcel, located in the Swift Run watershed. Those options include selling the structure if possible, or demolishing the house. Most of the scenarios involved describe an outcome of demolishing the house.

The plan also states:

For some policy goals, the City may consider commissioning hydrologic studies of these areas. For example, a new study of the Swift Run floodplain and floodway may show that the Springbrook parcels (3432 Platt, etc.) are outside the floodplain, or at least the floodway.

And it turns out the new FEMA maps that the council is being asked to approve no longer show the property in the floodplain.

By way of background, a “regulatory floodway” for FEMA means “the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.” A “floodplain” is described in the metadata associated with the floodplain map files in the city of Ann Arbor Data Catalog as “That portion of the river valley, adjacent to the channel, which is built of sediments deposited during the present geological / climatic regime. Based on statistically derived hydrologic recurrence intervals, a portion of the land adjacent to the watercourse experiences bank full overflow during flood stage episodes.”

Here are some images captured from the city-county online FEMA maps that show the changed status of 3432 Platt Road. The mapping interface allows users to toggle layers on and off, to view the 1992 floodplains and floodways, and contrast them with the 2012 floodways and floodplains. [For other Ann Arbor maps options, start here: Ann Arbor maps. Those maps provide answers if you're ever curious about locations of all the streetlights or trees in the city.]


3432 Platt highlighted in yellow. The 1992 floodplain is indicated with green hatching. The parcel is indicated as being mostly inside the floodplain.


3432 Platt highlighted in yellow. The blue region is the 2012 floodway. The green region is the 2012 floodplain.


Among the layer options that users can toggle on and off is one showing buildings (dark green areas) and parcels (light green areas) that were previously but are no longer classified as within the floodplain.

The last image in that set contains a piece of information that probably needs to be updated. It indicates a building at the 3432 Platt location. We’ve already seen a satellite image (above) from 2010 showing just open space – so the house did, in fact, get demolished just as Kunselman had written. In fact, Sumedh Bahl, the city’s community services area administrator, added confirmation by writing to The Chronicle that as near as he could determine, it was general fund money that had been used for the demolition.

But when did the demolition take place?

Based on the 2007 flood mitigation plan, the house was still standing in 2007. Given that the city-county online mapping service actually includes layers for historical satellite imagery, I figured I could identify the last year in which a house appeared in the satellite image, and narrow down the timeframe. The 2009 imagery shows open space. The 2008 imagery still shows a house. But it shows something else, too. In the image below, that sure looks to me like a yellow backhoe and a dumpster. Demolition day was also satellite flyover day:

Backhoe 3432 Platt

2008 satellite imagery for 3432 Platt Road (Image links to animated sequence of satellite images from 2005-2010.)

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  1. By Andy Brush
    February 21, 2012 at 2:13 pm | permalink

    Dave – nice use of online tools for detective work. Amazing that the flyover caught the demolition equipment – lucky that they were working on a day without clouds.

    The public mapping system that you used is probably the most public of the many IT collaborations between the City of Ann Arbor and Washtenaw County. City and County each paid half the acquisition cost and half of annual maintenance. Taxpayers save because we didn’t each need to buy our own system. We also share a data center, but that isn’t so obvious from outside.

  2. By Bob Elton
    February 21, 2012 at 3:07 pm | permalink


    Having had some experience with floddplains and the required flood insurance, I wonder if the lucky property owners whose houses are now in a flood plain will get a notice from the city? Or will teh city just tell the mortgage companies directly? As I recall, flood insurance these days is about a $100 a month hit.

    Likewise, will the really lucky property owners who are no longer in a floodplain get a notice fromthe city, so they can cancel their exorbitant flood insurance?

    Curious to know.

    Bob Elton

  3. February 21, 2012 at 5:07 pm | permalink

    Re: [2] Were letters sent out to affected property owners?


    Letter to those with property that changed to designation within floodplain:

    Dear Property Owner:

    The Federal Emergency Management Agency (FEMA) will be issuing new Flood Insurance Rate Maps (FIRM) on April 03, 2012. These maps may change the flood zone designation for your property located in the City of Ann Arbor. Based on a review of the new maps by the City staff, your property may now be mapped in an area that requires the purchase of flood insurance. If you have a mortgage and the structure(s) is determined to be in a Special Flood Hazard Area (floodplain) by your lender, you will be required by your lender to purchase flood insurance. There are several courses of action available to you:

    1. Do Nothing – When the new maps become effective in April your mortgage company (if applicable) will review them, and if they find that the structure(s) is now in an area that requires flood insurance, your lender will contact you and direct you to purchase flood insurance.

    2. Purchase Flood Insurance – All private insurance writers have the ability to provide flood insurance through the National Flood Insurance Program. Contact your insurance agent to inquire about rates for your structure.

    The new flood maps are available on the City of Ann Arbor’s web page at:

    Please note that these maps are a product of FEMA. The City can only offer you information concerning your options, but the final determination is between your mortgage company and FEMA.

    If after reviewing the flood maps you feel as if your structure(s) is not in the floodplain you may apply to FEMA for a Letter of Map Amendment (LOMA). A LOMA specifies a structure’s location relative to the Special Flood Hazard Area (floodplain). This process entails hiring a Licensed Land Surveyor or a Registered Professional Engineer. Additional information about the LOMA process can be found at: To learn about the risk of flooding, visit the website

    Letter to those with property that changed to designation outside floodplain:

    Dear Property Owner:

    The Federal Emergency Management Agency (FEMA) will be issuing new Flood Insurance Rate Maps (FIRM) on April 03, 2012. Upon review by City staff, it appears that a structure(s) on your property will no longer be in a designated Special Flood Hazard Area (floodplain).

    The new flood maps are available for review on the City of Ann Arbor’s web page at:

    If you are currently paying for flood insurance, you are encouraged to call your mortgage company about the possibility that they will now drop this requirement.

    Although flood insurance may no longer be required for your property, FEMA encourages homeowners to continue coverage even though the structure(s) appears to be mapped outside of the Special Flood Hazard Area (floodplain). If you decide to continue your flood insurance, the rate could be lower due to the new flood designation. To learn about the risk of flooding, visit the website

  4. February 21, 2012 at 7:44 pm | permalink

    Are our tax dollars being used to pay for the eWashtenaw GIS web site? That web site requires the use of a non-standard, proprietary tool available only from Microsoft. I’m unable to view it from any of the computers or other Internet devices in my house. Is there some reason the maps can’t be delivered using standard tools and protocols so that everyone can use them?

  5. By cosmonıcan
    February 21, 2012 at 10:14 pm | permalink

    Jim, I see the maps just fine on a Mac, the Silverlight plugin is free. If I feel violated, it’s only to be finding out twenty years late that Apple is evil, not Microsoft—well, at least they are equally horrible. Murderous slaveowners both.

  6. By TJ
    February 21, 2012 at 10:46 pm | permalink

    Is it Silverlight or an ESRI plug-in? Either way, it’s working on the MacBook Pro I’m sitting in front of. I suspect the owner keeps silverlight up to date so he can watch sports online…

  7. February 22, 2012 at 9:39 am | permalink

    So do I need to go buy a $1000 Mac to see the maps, after already sending thousands of dollars in property taxes to the county?

  8. February 22, 2012 at 10:00 am | permalink

    Would be nice if we had some current data to backup the modeling done to produce the maps. Even the consultant who did the maps for FEMA said they had very little data to calibrate the models for the Allen’s Creek map.

    We’re still using 1968 data from the last big flood!

    We have $1M for watershed art placed in the Allen’s Creek watershed (and other projects that use stormwater fees: paving streets, cutting and planing trees, police and forester) but not about 1/4 of that to collect data to make these maps meaningful to help protect life, health and property. UofM is also heavily negativity impacting the watershed but little or no help there either.

    There is some talk of now doing data collection and model calibration which is good, and long overdue and greatly needed.

  9. By cosmonıcan
    February 22, 2012 at 10:29 am | permalink

    #7 Jim: Silverlight is a Microsoft product, it works on all standard platforms, free for all. It is their version of Flash. Mac is not needed. Yes, the maps are visible with a Silverlight client software, not ESRI, the map window identifies itself as “Geocortex Viewer for Silverlight.’

    What kind of computer do you use? Some old Heathkit set you soldered together with a woodburning tool? Unless that’s what you’re using, they probably have something for you: [link]

  10. By Karen Hart
    February 27, 2012 at 5:44 pm | permalink

    To find out when demolition occurred, you could check the Building Dept. records– a permit is required for demolition. Then you could figure out that the demolition took place between them & about 6 months after.

  11. February 27, 2012 at 9:20 pm | permalink

    I was very pleased with the map application. I have a generic PC with XP, use a FireFox browser and Silverlight is installed. The application lets you move around, magnify and then select an area to print as a PDF or insert into a report. It even has a choice about “drawing on the map”. I didn’t try anything that fancy, but it worked well for me without much fuss.

  12. By Kasbak
    February 29, 2012 at 12:54 pm | permalink

    This article was mentioned in another government technology blog: [link]