12/14/11

The overriding challenge for our generation

Global warming is going to require us all to change--if not to stop warming, then to adapt to a warmer planet.

If that's not daunting enough, we have to change to avoid a world-wide resource crunch.  I found the following short essay explaining this economic challenge.  It's by a respected researcher, Lester Brown.

Reforming how we use water is an important part of our necessary change.

Green streets in Sunset Village?

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Sunset Village already has a rural feel, especially in parts of the neighborhood without curbs.

Residents love their curbless streets, like Hammersley Av.

Imagine how much more verdant it would look, with rain gardens bordering these streets.

Madison has a rain garden program, where the City builds the gardens when streets are resurfaced--sharing the costs with residents.  That means a neighborhood might have to wait many years.

But on curbless streets, gardens and swales (depressions) can be built now--with less cost, and only minor modifications to the gutter area.

12/13/11

Winter solstice bonfire

 
Celebrate the return of light!
Sunday December 18
6:00 pm-10:00 pm
 
* * *
at the Campfire Circle
Glenwood Children's Park
just SW of the corner of Glenway & Gregory streets.

To add to the festivities, there will be live music, poetry reading, and photos to share on the web. This year's event is being organized by Peter Nause, Parks Committee Chair, Dudgeon-Monroe Neighborhood Association: secnatland@yahoo.com

12/6/11

Snapping turtles in our lakes

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Last summer, I encountered this big fella crossing the bike path along Lake Mendota, near where Willow Creek comes into University Bay.  No doubt these turtles inhabit all our lakes and small ponds.

Common snapping turtle near Lake Mendota.

Wingra springs threatened by heavy pumping

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Over the years, a number of springs on the shores of Lake Wingra have gone dry.  Vigorous springflow is important, because it helps to keep Lake Wingra clean.  Improved spring flow is part of the restoration plan for the lake.

The Odana Infiltration Project, costing over $2 million, was supposed to restore groundwater in the area by pumping stormwater into the ground.  But now that project is in limbo, since it was found that the groundwater was being contaminated--over legal limits--from the salty runoff they were pumping.

Still, a number of springs in the area continue to flow--to the delight of residents in the area.

Western Council Ring Spring--a window into a healthy underground.

Now, heavy pumping of groundwater is occurring at two construction sites in the area:

Parman Place at Monroe & Glenway St

The blue hose to the left is carrying the pumped groundwater.

Steve Glass sent me the following report:

You may have heard the recent report that excavation at the Parman's Place project has opened up a large underground water vein or spring (estimated flow rate of >50 gallons per minute, but no one will really know until it is measured with a pygmy flow meter).

According to reports, "the contractor is de-watering the site (under their de-watering permit related to petroleum contamination of the site) and diverting the flow into the sanitary storm sewer."

Also, according to reports, "the contractor expects that continuous pumping will be required to keep the sub-grade de-watered."


These reports and the possibility of continuous pumping raise numerous ecological and hydrological issues for the watershed, the lake itself, and the wetlands bordering it.

There are many unknowns. For example, scientists don't know with certainty the groundwater flow path, so the major question is how will this new spring opening impact existing ground water discharge rates and flow patterns? Increase them? Decrease them? No impact?

Ken Bradbury of the Geological and Natural History Survey has suggested (according to one source) that Parman's construction might disrupt flow to existing springs and pointed to the nearby Council Spring complex just off Arbor Drive in the Arboretum as a possible candidate for disrupted flow.

We have a record of recent flow rates (gallons per minute) for the past few years for the Council Springs complex and will be able to make some comparison of before and after flow rates.
 
"Continuous pumping" over many years--sounds like a big waste of energy.  Could the groundwater be used for heating and cooling.... or for a beautiful fountain?
 
Next to Wingra Park behind Jac's restaurant
 
 
At this second construction site, there is a lot of groundwater flowing into this excavation, requiring a lot of pumping.  As required by law, the flow is being filtered through a large bladder resting next to Arbor Dr. 
 
Water from the bladder is seeping into the storm sewer--hence it's lost from the ground and from the springs.
 
Another problem is that a lot of sediment is escaping from the bladder, and getting into the gutter.  It's only a short distance to the lake.  Sediment is the main way that phosphorus gets into lakes, to stimulate noxious weed growth.
 
Both problems--loss of groundwater and sediment--could be solved if the bladder can be moved to a depression in Wingra Park just across Arbor Dr.   In that location (right), the water would return to the water table, and the sediment would be harmless.
 
This construction site is violating regulations by leaving the streets very dusty and unswept after each working day.
 
The  pumping at both sites is within a 1200 foot distance from the spring--and may therefore be subject to regulation.
 
Teach-in at the springs
 
David Liebl led a group to the Council Ring Springs to talk about the issues, according to a post on alder Sue Ellingson's facebook site.
 
Below: East and west branches of the Council Ring Spring.



If you love the springs, make a donation to Friends of Lake Wingra.

Green gooses: Rain gardens that don't work


Hardly anyone remembers the Spruce Goose. It was the largest airplane ever built--made entirely of wood, with eight engines and wings longer than a 747’s. It was completed too late for use in WW-II, and flew only once, to an altitude of 70 feet.

For some, it’s a symbol of technology that doesn’t work.

There’s plenty of incentive to make sure planes fly safely. But often, there’s no incentive to make sure rain gardens work.  Sometimes, owners don’t go out in the rain to to see if runoff even gets into the garden, before paying the contractor.

One reason why some rain gardens fail is that the runoff simply misses them. In most cases, this could be corrected with a few ridges of asphalt, to redirect the flow.

Metclafe’s Sentry

This is the most ineffective rain garden I've seen.  In this large parking lot, there are long rain gardens between rows of parking, with gaps in the curb to admit runoff.

Despite heavy rainfall, no runoff is entering this rain garden, because of improper grading.

During a heavy downpour, almost all the runoff simply failed to enter the gardens. This was partly because the gardens and their openings weren’t much lower than the gutter. And partly because there was nothing in the gutter to deflect the fast-moving gutter flow towards the garden (below). More photos.




Visitor’s Parking area at MG&E

In 2003, the drainage of this large parking lot became a DNR experiment to test how well a chamber with special filters could clean the runoff, before it escaped to Lake Monona.
They tested the runoff before it entered the filters, and after it came out, to see how well the filters worked.

Early on, the researchers noticed a lot less rainwater was coming out of the filter, compared to what fell on the lot. So they watched the parking area during rain, and "drew a red line" around the area that actually drained to the filters.

MG&E parking lot, site of the filter experiment.
The yellow line outlines the whole lot; the red line outlines the area that actually drains to the filter.

Although the parking area was 1.3 acres, they found that only .91 acres of the lot drained to the filters. The rest spilled out into the bordering streets, bypassing the filter. In other words, because the lot wasn't sloped correctly to capture all the water, only 70% of the water falling on the lot actually went to the filter. For the runoff that actually made it to the device, the filters worked well.

More photos during rain. More on the filter. Scientific report.

Sequoya Commons

I'm a big fan of this large rain garden. It's beautiful, and for the most part, very effective. But runoff coming down the north side of the lot misses the garden, and instead flows out the east entrance to the street (below).




Plugged openings

Other rain gardens fail because the openings become plugged with debris.

Clogged opening for a terrace rain garden near West High School.
Later designs by the City have larger openings.