February 16, 2004 Thurston Nature Center Committee Meeting

7:00-8:30 pm, Thurston Elementary School Library

 

Present: Jan Baty, Vicki Botek, Jim Breck, Mike Conboy, Tom Edsall, Neal Foster, Heidi Koester, David Miller, Katie Richter, Elsa Stuber, Dave Szczygiel, Bram Van Leer, Lia Van Leer

 

The meeting was called to order at 7:00 pm.(Jim took minutes until Vicki arrived.)

A voting roster was proposed and approved: Janet Baty, Vicki Botek, Jim Breck, Beth Caldwell, Mike Conboy, Tom Edsall, Neal Foster, Michelle Hat, Heidi Koester, Tim Markel, David Miller, Katie Richter, Dave Szczygiel, Elsa Stuber, Lia or Bram Van Leer.

 

The minutes of the previous meeting were addressed.Vicki pointed out that it should be ďRobertís,Ē not ďRobertsíĒ in Robertís Rules of Order.Neal moved to approve the minutes.Tom seconded.All in favor; none opposed; none abstained.

 

Communications

Neal reported on the links he has put on the website to information about different birds which have been spotted in the TNC.Heíll get historical TNC photos to from Jim to put up on the site.

 

Neal attended two Huron River Watershed meetings and shared some of what he had learned.For example, as development increases in an area, so does the amount of impervious surfaces, leading to flash floods.When more than 25% of the surface is impervious, quality of aquatic habitat downstream drops catastrophically.Forty percent of the Millerís Creek watershed is impervious surface.The idea of the pond part of storm water control was brought up.Surprisingly, the decay of vegetation in the water helps remove phosphorous.Finally, the beetle project to has been effective in controlling purple loosestrife in an area near Saginaw Bay.

 

Water

Tom presented a recommendation development of a restoration plan for Thurston Pond.It stated goals and vision, followed by a problem statement including a table representing pond conditions in its original state (clear water) vs. pond conditions now (turbid water) and an explanation of how and why the pond has degraded.Heidi suggested a few additions to the explanation.The report ended with recommended actions.

 

The problem statement was discussed.Heidi explained that it had been prepared to present to the school, as part of the process we defined at the January meeting.Dave suggested pursuing grant sources.Elsa asked how we would determine the cost of any actions.Determining actions to take and how to pay for them will come later in the process.Elsa moved to approve the problem statement with Heidiís edits.Neal seconded.All in favor; none opposed; none abstained.The next step will be to formulate a goals statement for the March meeting.

 

Tom recommended using the Masterís Study when working on the goals.

Heidi shared the Lakeline magazine with those who had missed it at the previous meeting.

 

Scott Dierks, a hydrologist with Ayres, Lewis, Norris & May, Inc., which was part of the 1-1/2 year Millerís Creek (and Watershed) Study initiated by Pfizer, presented his findings on the hydrology of the area around Thurston Pond to the committee.A summary of his points follows.

Thurston Pond is part of the headwaters of Millerís Creek.The inlets and (Georgetown and Clague) probably donít discharge very often into the pond, only as storm overflow.Since the cityís project of footing drain disconnects from the sanitary sewers started, it has been noticed that the flow from a couple of the new sump pumps just east of the pond are running high.This indicates a spring, which is probably feeding the pond.[Elsa noted that when the Shefman Terrace houses were built, one of the basements flooded immediately, probably from a spring.]Ann Arbor averages about 32Ē of rain per year.Most of the pond water evaporates.We have had a few ďdryĒ years without major events, so there has not been much extra water coming from the neighborhoods.Water rarely flows out the pondís outlets; the pond is like overflow storage.Relatively little water from Thurston Pond actually ever gets into Millerís Creek.

 

There is sometimes no water in the streams in the watershed, and then when it rains, they flow dramatically and suddenly.

 

Surface water runoff in the neighborhoods used to flow through the pond basin and into the reach of Millerís Creek beginning at Plymouth Road.However, the pond now captures and holds some of this runoff and the storm water system built by the city captures the rest and diverts most of around the pond and into Millerís Creek at Plymouth Road.

 

The study is measuring water depths continuously at Geddes, Glazier Way and Plymouth.

The storm water drain system is out of date.

 

If more of the neighborhood storm water flow could be diverted directly to Thurston Pond, as was the case before the neighborhoods were built, there would be a gradual release into Millerís Creek.This would improve water quality at the Pfizer sampling sites downstream of the pond.

 

Road salts may contribute to conductivity/ions in water downstream

.

The water level of the pond is subject to the weather, and will continue to fluctuate.

 

Sediment is not necessarily coming from the watershed.Because the inlet flow is infrequent; the pond is probably producing some of its own sediment.

 

The health of Millerís Creek would improve with increased base flow and reduced ďflashyĒ flows.Itís not clear exactly how Thurston Pond could be adjusted to contribute to these goals.We could consider the value and feasibility of moving the pond more toward a wetland, with less standing water but perhaps more water flow.Keeping the pond as a pond might also help Millerís Creek, if some storm flows were directed to the pond.

 

Options

A.†††† A little more water could be made to come in from the storm system.Clague water goes to Plymouth and the creek unless there is more than one or two inches.[Heidi noted that the Clague inlet pipe seems to be trickling fairly often.]

††††† Inlets could be filtered.

††††† Redirecting pipes could be expensive.

††††† Miller Creek is steep, so events cause flashes that cut the bed deep and the creek rarely overflows.

B.†† If the pond reverted to wetland, it could still provide 2-3 days storage during events.It would be complicated for the vegetation.It could be hydraulically regulated.

C.     For the pond to affect Millerís Creek, its outlets would have to be lower.

 

Scott recommended that we continue to monitor the pond, especially water levels related to weather.He did not make any specific recommendations about whether the pond should be converted to a wetland or kept as a pond.

 

Scott suggested that the TNC is probably eligible for education, monitoring and restorations grants.

 

Mike suggested that we could use the vernal pond (near the school property) to add to the pond.Could we stop the drain on that side so water would go into the pond, not the drain?

 

The final report of the study will be available soon at http://www.aamillerscreek.org/

.The Millerís Creek Action Team includes representative from the city, Pfizer, the University of Michigan and other groups.It is going from the study phase into the implementation phase.Someone from the TNC committee might be eligible to join.

 

The meeting was adjourned at 8:30 pm.The next meeting is March 15.