View of Depot Street from the south. The railroad track curves northward as it passes by Argo Dam, visible at the top of this image.

They were briefed on the status of the 721 N. Main property’s status with respect to potential environmental contamination – which is apparently less certain than what’s been portrayed recently by elected officials.

Task force members were also briefed on a related project that’s in its initial stages: a feasibility study for opening up the railroad berm separating the area south of Depot Street (including 721 N. Main) from the Huron River. The railroad tracks run along the top of the berm. The idea is to study the possible impact of replacing the solid berm – which acts as a dam for stormwater flow from the Allen Creek creekshed – with a culvert or a trestled system for suspending the tracks.

The primary impetus behind the berm project is stormwater management and flood mitigation. That’s reflected by the fact that the source of funds for the roughly $50,000 feasibility study would be from the city’s stormwater utility. The feasibility study would move ahead only if it’s approved by the city council, which will likely have the item on its agenda in about two months.

But the railroad berm study also has implications for pedestrian connections and riverside access – which the task force is supposed to study. The task force is asked to create a vision that, among other things, improves pedestrian and bicycle connections to Bandemer Park and increases public access to riverside parks.

So the railroad berm feasibility study has been coordinated with the goal of pedestrian accessibility. The RFP (request for proposals) for the study includes among its tasks a study of the potential for non-motorized access through the railroad berm.

The problematic character of pedestrian movement on the North Main corridor was evident during the July 25 tour. As the tour group made its way northward toward the M-14 entrance ramp, it repeated a pattern of fracturing into smaller clusters and re-grouping. That was partly a function of the size of the group (about 10 people), but also the corridor itself.

The relatively narrow walkable space – between the road to the left, and fences, buildings or vegetation on the right – features sidewalk slabs in need of repair and sections of dirt path that require single-file passage. Noise from rush hour traffic made conversation difficult along the way.

A year from now, on July 31, 2013, the task force is supposed to deliver its report on a vision for the corridor. Earlier than that, by the end of 2012, the task force has been asked to provide a recommendation on the use of 721 N. Main.

For task force members and members of the public, the same tour will be repeated on Aug. 1, starting at 5 p.m. from 721 N. Main.

721 N. Main

The July 25 tour began at the city-owned 721 N. Main site. City staff discussed two issues with task force members: where the floodway and floodplain lines are for the property; and the status of the site’s environmental clearance.

721 N. Main: Environmental

Compared to 415 W. Washington – another city-owned property that’s the focus of attention regarding its future disposition – 721 N. Main has been portrayed by mayor John Hieftje at recent meetings of the city council as not suffering from environmental contamination. And that’s the basis of a decision to try to make 721 N. Main the city’s first greenway park – an effort that would be supported through an eventual grant application by the city to Michigan’s Department of Natural Resources Trust Fund.

It’s the annual spring application deadline for the DNR trust fund grant that is driving the earlier timeline for the task force recommendation on 721 N. Main – Dec. 31, 2012, instead of six months later for a recommendation on the whole North Main-Huron River corridor.

Fluid lines formerly used for vehicle repair in 721 N. Main building, which previously served as the city's vehicle maintenance and repair facility.

But during the tour, city environmental coordinator Matt Naud addressed the possible perception that the 721 N. Main site has an environmental clearance and the idea that it has been certified as not contaminated. He traced that perception to the fact that the city had removed some underground gas storage tanks from the site – and for the confined area of those tanks, the soil had been remediated to the highest standard. So for the contamination that was known for a fact at 721 N. Main, Naud said, it had been cleaned up. But there was potentially contamination that was unknown in the rest of the site.

For the site as a whole, Naud told the group, 721 N. Main has not had a phase 1 environmental survey done – to study the history of past uses. Phase 2/3 environmental surveys would establish what contaminants are present, if any, and at what levels and locations.

From the quick peek the tour group was given inside the main building at 721 N. Main, the past use of that building as a vehicle maintenance and repair facility indicates the potential for lingering contamination at the site. Aside from possible actual environmental contamination, the building is filled with clutter, including the city councilmembers’ old chairs that were retired from service in May 2011.

Naud also indicated that the Allen Creek creekshed, as the creekshed with the most impervious surface in Ann Arbor, is also likely the “dirtiest.” And any environmental contamination from other sites in the creekshed would naturally migrate to the Allen Creek area – on which the 721 N. Main parcel sits. [The Allen Creek is conveyed underground through a pipe that exits into the Huron River just below the Argo Dam.]

721 N. Main: Floodplain and Floodway

Jerry Hancock, the city’s stormwater and floodplain programs coordinator, also accompanied the tour group. He reviewed the status of a grant from the Federal Emergency Management Agency (FEMA) to demolish two of the buildings at the 721 N. Main site – those that are located in the floodway. The main building is in the floodplain, not the floodway, and is not included in the FEMA grant, which has been awarded and is worth around $100,000. The main building wasn’t included, he said, due in part to the fact that there’s been no public process around what the future of the building should be.

The 721 N. Main parcel is west of Main Street. The main building on the site is oriented north-south, visible just north of the blue-shaded area (the FEMA floodway) and inside the green area (the FEMA floodplain). The FEMA grant for demolishing buildings at 721 N. Main does not include the main building. (Links to higher resolution image.)

Although the grant for demolishing buildings at 721 N. Main had already been awarded by FEMA, Hancock indicated that a delay by the Michigan Dept. of Transportation was long enough that the city’s All-Hazard Plan (for flood mitigation) had expired in the interim. The city is in the process of getting that plan renewed. The receipt of the FEMA funds is contingent on having an up-to-date All-Hazard Plan.

Removal of structures in the floodway – like the two buildings on the 721 N. Main site – is part of the city’s general strategy to reduce flood risk throughout Ann Arbor. Responding to questions from the tour group, Hancock explained that the FEMA flood maps aren’t merely an indicator of low areas – that is, the maps do not simply provide a topographical survey. Although the topography is a significant component of the data that factors into drawing flood maps, he said, the impact of built structures can be to push water into higher elevations.

Railroad Berm Feasibility Study

Hancock also briefed the tour group on a feasibility study for a project near Depot Street, that – if eventually constructed – could have an impact on the floodway maps for the area as far away as 721 N. Main. The project is also potentially connected to improvements in non-motorized transportation.

The idea is to open up some portion of the berm that the railroad track sits on – between Depot Street and the Huron River – to allow a less impeded flow of stormwater into the Huron River. It’s one of 56 different specific projects listed out in the city’s flood mitigation plan:

Project 51: Railroad Berm Fill Removal. Examine ways to remove the berm located between Depot St. and the Huron River, as well as other portions of the railroad berm in the Allen Creek corridor, to allow floodwater to travel to the river without a major barrier impeding the flow, acting like a dam. Examine the costs of creating a terraced rail system. Compare costs estimates to complete project with the estimated costs of removal/relocating

The city issued an RFP (request for proposals) with a deadline for response of June 25, 2012: “Allen Creek Railroad Berm Opening Feasibility Study” Representatives from 10 different firms attended a pre-bid meeting on June 12, 2012. The city received proposals from six of them.

The railroad track berm from the Depot Street side of the track, looking southeastward. The Broadway bridges are visible in the distance.

The top two firms in the scoring system were OHM and Spicer Group. The five tasks identified in the RFP are: (1) information gathering; (2) option development; (3) option analysis and stakeholder engagement; (4) conceptual design development; and (5) benefit-cost analysis.

At the city council’s March 19, 2012 meeting, public services area administrator Craig Hupy had responded to questions about flooding along Depot Street during a recent rainstorm. On that occasion, Hupy mentioned the physical, dam-like barrier presented by the railroad berm as a challenge in any improvements to the city’s ability to improve stormwater flow.

Hupy is serving as head of public services on an interim basis, after Sue McCormick’s departure. His permanent position is head of the “systems planning” unit for the city. Systems planning includes not just stormwater manager Jerry Hancock, but also the city’s transportation program manager, Eli Cooper. So according to Hancock, staff were easily able to see a potential connection between the flood mitigation function of a railroad berm project and the potential for non-motorized transportation access to the river, for pedestrians and bicyclists.

The desire for pedestrian and bicycle access across the railroad track was identified separately from the impact that opening the berm could have on flood mitigation. Excerpt from the city's 2007 Non-Motorized Transportation Plan. (Image links to higher resolution file.)

One of the criteria to be applied in task #3 of the RFP, the option analysis, is this: “Possibilities for a shared-use non-motorized path through berm.” And as a part of task #4, the consultant is supposed to: “Develop a design concept for a shared-use non-motorized path through the berm and determine the safety issues due to the floodplain function.”

Hancock described to the tour group how he would be meeting the following morning with one of the respondents to the RFP. That meeting was with OHM, the city’s preferred firm as a result of the RFP review process, and was meant to finalize the details of the scope of work. If OHM and the city can settle on those details, OHM would be hired only after a contract is approved by the city council. It’s expected that the feasibility study would be on the city council’s agenda in about two months. Hancock told The Chronicle that the $50,000 project budget for the study would be drawn from the city’s stormwater utility fund.

On approval by the city council, the project would be completed in a timeframe that Hancock estimated at around 4-6 months.

FEMA flood map that includes the area of study for the railroad berm feasibility study.

Depending on the result of the feasibility study and the resulting concept that the consultant produces, it could become a project that is added to the city’s formal capital improvements plan (CIP). The CIP includes projects the city has identified as useful, even if a funding mechanism for the actual capital project has not been identified.

Hancock told The Chronicle that the capital project itself would be very expensive – with costs driven in part by the fact that it involves a working railroad. Although there’s a pending transaction to transfer ownership from Norfolk Southern to the Michigan Dept. of Transportation, he said, the rail company will continue to have access rights to run its trains under whatever agreement is struck with MDOT.

The Chronicle could not survive without regular voluntary subscriptions to support our coverage of local government issues. Click this link for details: Subscribe to The Chronicle. And if you’re already supporting us, please encourage your friends, neighbors and colleagues to help support The Chronicle, too!

View of Thurston Pond looking east.

Heading east out of downtown Ann Arbor, by the time Plymouth Road nears the 200-foot-high, 500,000-gallon water tower – painted with blue sky and clouds – west side Ann Arbor residents who stick mostly close to their own neighborhoods could easily forget this is still Ann Arbor. A couple of weeks ago The Chronicle headed up that direction, turning left just before the water tower onto Georgetown Boulevard. We were meeting Neal Foster, a neighbor of Thurston Pond and retired scientist, who had agreed to give us a tour of this 8.5 acre pond, which is a major feature of the Thurston Nature Center.

In his early academic career – inspired in part by his father’s guppy tank – Foster’s research specialty was killifishes, but what he says he’s best at and enjoys most is “explaining things to people.” And The Chronicle took full advantage of that talent. After gathering up some buckets, nets and waders at Neal’s house, we headed up to the southern edge of the pond where Yorktown Drive provides easy access. Before donning the waders and Wellingtons in an attempt to gather some aquatic creatures, we took a clockwise tour of the pond.

Willow trees on the southwest side of Thurston Pond.

As we began working our way around the pond, Thurston Elementary’s playground was on our left. The Thurston Nature Center is intimately connected to the school – The TNC Committee is a sub-committee of the Parent Teacher Organization at Thurston Elementary. Piled next to the first section of trail was a heap of wood chips, which Foster explained would be spread by volunteers onto the trail as a part of a work detail scheduled for an upcoming weekend. Walking the trail, we encountered benches oriented towards the pond, which presumably at one time had a sight-line to the water, but any glimpses of the pond today from those benches are obscured by phragmites (an invasive reed) or else by the towering willow trees.

Clear sight lines to the water probably existed back in the late ’60s when the pond took its current shape. The existing wetland had been dug out as the area was developed residentially, and some of the construction debris was tossed into the 2- to 6-foot deep pond.

As we neared the western side of the pond, Foster pointed out a grate amongst the vegetation: an overflow storm drain leading to Miller’s Creek. It rarely comes into play, said Foster. The settling over time of the berm on the western side of the pond, which is designed to keep the water levels higher, means that when the pond does overflow, it tends to do so at locations other than the designed drains, and winds up soaking into the ground, instead of being led to Miller’s Creek via the drains.

Overflow per se is not something to be prevented. On the contrary, what Thurston Pond needs, says Foster, is more flow in and more flow out, to help correct what has become an over-rich nutrient mix in the water. Where does the flow-in come from? It currently comes from natural pooling of water when it rains. In that regard, Thurston Pond is akin to a giant rain puddle. But in addition to the natural pooling, there is engineered flow as well. Just past a wooden walking bridge on the western edge of the pond we found the opening of the storm drain from the Clague Middle School parking lot into the pond.

Possible future location of a storm drain leading down from Bluett Road and Antietam Drive.

A little further along the path, Foster pointed out a concrete stairway leading down from the Bluett Road and Antietam Drive area, which he said could be the location of an additional storm drain inlet into the pond. The 30-inch pipe would be installed by tunneling under the stairway instead of trenching and replacing the stairway – a newly re-constructed stairway would incur the additional expenses associated with being ADA compliant.

The wooden walking bridge we had crossed earlier had a newly replaced board on it. Asked who would have undertaken the repair, Foster figured it could have been Mike Conboy, the same name he cited as a real resource for information on the old growth trees we had been walking past.

As we made the turn eastward and rounded the deepest section of the pond, it became increasingly easier to get a view of the water. This is in part due to the practice of clearing brush all the way to the water’s edge by homeowners whose property abuts the pond. Foster said he wished they would let the natural flora have its way. Arriving back at the Yorktown Drive access, he said that the implementation of a no-mowing strategy at that location by the Orchard Hills Athletic Club had successfully discouraged the flocking of Canadian geese on the banks – which, unchecked, will make a prodigious contribution of manure to the lawn.

Neal Foster wields his net at the southern edge of Thurston Pond.

It was time for Foster to pull on his waders. The Chronicle pulled on some size-13 Wellingtons that he lent us, which were more than adequate to keep our feet dry. Foster first deployed a fine mesh suitable for snagging plankton-size aquatic life, taking care to swish his figure-eights through the water near the surface to protect the delicate weave of the net. Depositing the contents from the net into a plastic jar, he would later speculate that it was only detritus that had been captured.

But when Foster broke out the coarser net, he met with more visible success: fathead minnows. And that success was witnessed by Laura MacGregor, who was walking home with her daughter, Sophie Stillwagon, who she’d picked up from kindergarten at Thurston Elementary. MacGregor said they walked home past the pond nearly every day. Foster encouraged the pair to come to the upcoming Orchard Hills-Maplewood Homeowners Association fall festival – having some aquatic critters on hand for display at the festival was the motivation for the morning’s collection activities.

Fathead minnows aren’t the only aquatic life supported by Thurston Pond. Painted turtles and snapping turtles are definitely on the list as well. Foster said that the snapping turtles had a fairly easy time preying on ducklings and goslings, because the cloudy water allowed them to approach undetected. Not that the snapping turtles of Thurston Pond pose a real danger to humans – The Chronicle emerged from the shallow water unscathed, but with a deeper understanding of the range of neighborhoods in the city.

Sophie, Neil, and Laura check out the catch.

In front: Laura MacGregor and Sophie Stillwagon. In back: Neal Foster

Fathead minnows.