A riddle for greenway supporters

Riprap--12 years old (L.Coleman)             Articulated concrete blocks

When the City finally comes up with their plan for the ravine, I predict their plan will look something like this:
  • We propose keeping the stream open but lining the channel with riprap (or articulated concrete blocks--see previous photos) "because that costs the least, and our contractors know how to do it."
  • We will try to save as many trees as possible.
  • You say you want some nice landscaping and curves? We can't do that without breaking the budget, just for people living on two streets. Apply for a grant on your own--of have your properties each assessed $5000 to pay for it. 
As is turns out, no grants are available to enable 20 or so residents improve their backyards at some foundation's expense.  Since no one wants to pay, and no one knows how many trees will be cut, everyone reluctantly agrees to go ahead with the City plan.  They feel powerless.

But when the work is completed, residents are very disappointed and upset:
  • More trees were cut than they hoped , because the riprap is bulky and goes straight.
  • Big equipment got in there, and the ravine is completely changed--just an open scar that will take a long time to heal.
  • And when it does heal, the stream is long gone--underground.  Trickling invisibly between the cracks of the rocky rubble.
So, how can we change this future?  Change this dynamic?  Think about it.

I invite readers to post your ideas below, and to discuss the ideas others come up with.

Mary Norton proposes:
  • To prevent too many trees being cut, get a plan in advance of which trees will be cut, then have observers make sure plan is followed during construction.
  • For landscaping, volunteers remove stones from the creek bed to later use for creating terraces or holding back upper levels of soil.  Also use large limbs from trees that are felled for the same purpose. 
What do you propose for landscaping?


Riprap--pros and cons for bank reinforcement

Stopping erosion is one of the goals of the greenway project.  It's likely that City Engineering will propose riprap as the method for stabilizing the stream bank.  Riprap is essentially stone rubble that is laid down in a jumble to line a channel.

In one of my previous posts, I showed a photo of riprap installed only six months earlier along the SW bikeway. Lisa Coleman of City Engineering pointed out that as riprap ages, it begins to look better.  She submitted the photo below to make her point.

Riprap about 12 years after construction

Lisa told me: Here's "a photo of another riprap-lined channel in the Forest Hills Cemetery that was installed in the mid '90s. This photo was taken last summer (2008). The look of the riprap does change over time as it weathers, and it does fill in a little with vegetation (not always the most desirable vegetation, but vegetation still) over time."

I agree that Lisa has a point--that we have to think about how the riprap will look in, say, 10 years.

Based on that, I'm going to modify my pro-con list that I published earlier.

Advantages of riprap
  • Low cost initially
  • Low maintenance (if rocks are large enough)
Disadvantages of riprap in our greenway
  • Questionable aesthetics--looks like rubble at first, later looks better, with more vegetation.
  • Our stream requires relatively large stones because of large storm flow. The larger the stones, the more problems for children and the harder to fit into a narrow ravine.
  • Too bulky for use in tight places.  Cannot follow the twists and turns of our present stream.  We'll end up with a ravine partially filled in with stone.  Dangerous in the first years for children--who can trip or twist ankles
  • Emplacing riprap of large stones may require large equipment that will damage the area
  • The stream will become dry most of the time.
Let me explain this last point.  The riprap will be very porous, especially until all the spaces fill with sediment.  Hence the stream will flow underground more of the time.  Children like to play in water and in puddles.  For the first 5-10 years, there probably won't be any puddles except during heavy rain.  I'm not sure about after 10 years, but I think puddles will still be less likely.  In other words, the trickling stream we have in the upper portions will be gone.  And later if we can restore the groundwater, the stream will be less likely to come back.

The bulkiness of riprap means the channel will have to be wider, causing more trees to be cut.  Where the channel now curves around trees, it will be straightened, again eliminating more trees.

We get what we pay for.  If we take the cheapest option, we get the ugliest outcome.  I personally would like to hold out for something more attractive.   I would like to see our restored steam include:
  • Natural curves and natural variety.  All parts of the bank don't have to be the same.
  • A few little plunges that make sounds of rushing water
  • A few pools
  • Banks that are terraced, perhaps reinforced with stone
  • Woodland wildflowers and ferns growing on these terraces.
  • A narrow pathway, perhaps just dirt or stepping stones
  • As many trees preserved as possible
Most of these features are impossible with riprap--so that's why I am against riprap.  Riprap and landscaping are incompatible in tight places.

The following photos show new riprap at the corner of Fish Hatchery Rd. and West Beltline Highway, during a prolonged light rain.

Photos of underground streams

I stumbled across some fabulous photos of buried streams in the UK.  Click here.


Playing in ‘wild places’ is vital for children

Well-meaning safety concerns — as well as TV and video games — are keeping kids sedentary, indoors and away from the places their parents recall as the highlights of their own childhoods. But that may also restrict their appreciation, familiarity and enjoyment of natural environments, say University of Guelph landscape architecture researchers.

Prof. Nate Perkins, of the School of Environmental Design and Rural Development, believes wild places – hedgerows, woodlots and streams, to name a few — develop children’s imaginations in ways that structured and programmed play areas never can.

“I understand why parents may be afraid of the risks occurring outside of the home. But what they don’t recognize is that wild places can have many health benefits for their children,” he said.

Perkins and former graduate student Sarah McCans are looking into how wild places can be preserved for children’s play. They’re also taking a closer look at the availability of wild places, how many children use these spaces and ways to increase parents’ awareness of the benefits such places may hold for their children.

Perkins thinks the concerns he’s heard about wild places should be put in perspective. For example, he’s found that the No. 1 safety hazard in North American schools is actually the asphalt around schools. But natural areas in communities continue to decline because of safety concerns, while asphalt remains.

Surfaces aside, Perkins believes unstructured outdoor play is crucial to a child’s physical, psychological and social development. In particular, he says the outdoors can provide inspiration for more creative thinking. Children from rural and suburban areas, who generally spend more time outdoors, have more highly developed imaginations.

“Kids know more about rainforest ecology in Brazil than what’s going on in their own backyards,” said Perkins. “They have more environmental knowledge, but they don’t experience nearby nature and consequently they may not have the deep personal connections to the natural world that their parents may have.”

  What they saw in the puddle--bubbles sailing across frothy pollen

See this related post.

From a press release, Prof. Nate Perkins, School of Environmental Design and Rural Development, (519) 824-4120, Ext. 58758, perkins@uoguelph.ca, Dec. 7, 2004

Rain garden critters 2--How do they survive between rains?

If you were to examine a little wet soil from your rain garden, and put a drop on a microscope slide, you'd probably see a lot of rotifers.  Barely bigger than amoebas, they still consist of many cells.

Rotifers...  Males are "degenerate*"--how cool is that?
art by Elizabeth Buchsbaum

They vary in shape from ones attached to the bottom that look like flowers, to fat forms that float near the surface.  But all have what looks like a rotating wheel for a mouth.

What's interesting is how these aquatic creatures survive the dry spells between rains...

"Some rotifers can withstand drying" better than most microscopic critters.  "In this almost completely dried state they may live for years.  As soon as moisture appears, they swim about and feed actively.  Because of this capacity to resist drought, rotifers can live in places that are only termporarily wet, such as roof gutters, cemetery urns, rock crevices, among moss, and" in rain gardens.

"When the water evaporates, the animal contracts to a minimum volume and loses most of its water content.  Somtimes the animal itself dies but its contained eggs survive until moisture returns."

So, whether it's wet or dry, they are always ready to help break down the pollutants that wash into your garden.
* Degenerate means smaller and more simplified.  Why am I reminded of Homer Simpson?

Quotes from Animals Without Backbones, by Ralph Buchsbaum, 1948.


Childhood memories of our stream--by Craig Miller

Dear Mayor Cieslewicz,

Where did you like to play when you were a boy?

If you had the choice between a dirt access road and a mysterious forest with a tiny creek where you could float little boats you had made, I’m sure you would have chosen the latter. I know, because that’s where I played with my friends as a boy.

Known as “the ditch” by kids in the 1960s, today it is referred to as the Hillcrest-Upland Greenway. I was lucky enough to grow up in a house next to those wild woods. For me and my sisters and our friends from the Sunset, Westmoreland, and Hoyt neighborhoods, it was a magical realm. We played up and down its length, hopping on stepping-stones, peering into the mysterious tunnel that ran under Owen Drive, looking for bugs and toads and anything else we could find. We floated twigs, leaves, and those little boats we had made down the creek that flowed after even a short rain.

Adults may have enjoyed having patios and decks that overlooked it, but we didn’t care about that. We went down into the ditch. It fed our imaginations and, even as adults, our dreams. It was the only bit of wilderness that we knew of at that young age. And it was literally in our backyard, there for any kid who wanted to play. Not play a videogame, not play with the latest plastic toys from the mall, not play at an arranged “play date.” Just play.

One of my strongest childhood memories is of building a little red boat with my father. Together we chiseled it and sanded it and painted it red. I floated it down the creek and it got away, floating through the grate at Midvale Boulevard. I cried a long time over that boat, learning a small lesson about life and loss. I know as an adult I wouldn’t have that precious memory if neighborhood planners had done then what they’re considering now and filling in the creek bed.

My mother still lives in the house on Hillcrest I grew up in. Last summer, I took my own little daughters down into the ditch for a look around. They had heard plenty of stories about it. Back home in Minneapolis, I helped a few other parents create a rain garden at my oldest girl’s school. If we’re going to preach “save the environment” to our children, we have to be ready to walk that talk.

So for the kids that used to live near the ditch, the kids that live there now, and the kids who will live there some day, please let this little slice of wild space remain.

With hope,  Craig Miller, Minneapolis


Under the "hood" of your rain garden

If you are reading this blog, you probably know about the advantages of rain gardens:
  • They absorb the runoff from your roof, sidewalk, or street.
  • They recharge the soil and the groundwater.  The soil acts like a giant sponge to store and slowly recharge our lakes and streams.
  • Rain gardens filter the dirty runoff.
A filter just traps things; in the case of storm water, we're talking about sediment and pollutants. But rain gardens and the soil below them are much more than filters.  So let's peep below your garden, to see what's going on.

The soil harbors millions of organisms per cubic inch.  Not only bacteria, but fungi, larger microbes like amoebas, and multicellular critters--like earthworms, insects, millipedes, centipedes, mites, spiders, and all kinds of creepy-crawlies.  No doubt you're familiar with these larger inhabitants of the soil--the ones you can see.

But in the size range smaller than visible, yet much bigger than the microbes, is a whole world of animals.  Legions of wiggling things, rooting between the tiny grains of soil.  All these, from the worms to the microbes, are eating, breaking down, and metabolizing the pollutants that sink into your rain garden.  If one critter won't eat that oil from the street, or that antifreeze, the next one will.  

At great cost to taxpayers, the sewage plant tries to recreate what's going on in the rain garden, in order to digest your sewage.  But your rain garden does it without a pipe, does it locally, and for no cost.

In a rain storm, when pollutants wash off our streets and down the storm sewer, they head straight to the lakes.  Once there, bacteria and algae try to break them down.  But it's harder to do in the lakes.  There isn't as much oxygen, and there aren't as many critters as in your rain garden .  So the lakes start to stink, and who wants to swim where pollutants are being digested?  Better to let your rain garden do it.

It used to be that most of our water pollution came from big pipes--sewage plants or factories discharging into our lakes and streams.  Once we cleaned those pipes up, it came as a surprise that our waterways were still going downhill.  The culprit turned out to be "nonpoint source pollution."  This is shorthand for pollution from a myriad of tiny sources-- your dog... your auto... your lawn.  Most of these tiny sources are spilling onto pavement, and rain gardens can trap and purify those pollutants.

There are a myriad of sources of pollution, so we need a myriad of rain gardens.  Sure, you can pick up after your dog, and use less fertilizer.  All excellent ideas.  But the rain garden is the final trap for the nasty little things that slip by our defenses.  

All those ravenous little monsters in your rain garden are just waiting for their next meal.


Friends of Hillcrest-Upland Greenway

"I'm a friend of the greenway... 'cause if you kill the stream, where can I play? And what will happen to the mud... and to the animals--if it's all concrete?"

In these days of tight budgets and understaffed agencies, it helps for citizens to form groups. It gives legitimacy to their voice, and officials know who to consult and where to find volunteer help. Nowadays, nearly every park of any size across the country has a "Friends of XX Park." Recently a friends group formed for the greenway, and last week held an open house to meet neighbors and show the greenway.

Kathleen McElroy and neighbors helped start the group, and now Mary Norton is Acting Coordinator (233-3860). The group is gearing up for a public meeting on the greenway, with a date to be announced. They have a facebook page:

Issue that triggered the group
The City proposed to tear up the greenspace, cut into a stand of 300 old-growth trees, replace the sewer pipes, bury the stream in a pipe, level the area with fill, and top it all with a maintenance road. Neighbors have rallied against this threat to the wildlife, leafy ravine, and natural sounds of bird and stream. Deer, fox, possums, and 28 species of bird have been sighted in the area, including a red-tailed hawk that hunts here. While there are many values to the greenway, the rare urban stream is seen as the centerpiece. They say: "Our quality of life, tucked as we are into this quiet woods with it's intermittent water flow, will be immensely altered by this project."

What the friends group wants:
  • Retain the dense stand of trees
  • Stabilize & repair the sanitary sewer
  • Stop the erosion
  • Retain the open stream
  • Minimize construction damage to our property/easements
  • Retain privacy & safety along a now largely inaccessible pathway
  • No road through the greenway

How you can help

  • Write a letter, especially to Alder Chris Schmidt & Mayor Cieslewicz
  • Attend the public hearing--date to be announced
  • Spread the word
  • Make a "Save the Greenway" sign for your yard
  • Join the Facebook page and follow this blog
  • Install rain gardens and rain barrels in your yard
  • Pledge to help with future maintenance of the greenway

Dave Cieslewicz, Office of the Mayor, City of Madison, Madison, WI 53703, 266-4611, mayor@cityofmadison.com
Alderman Chris Schmidt, 4210 Odana Road, Madison, WI 53711, district11@cityofmadison.com

"I'm a friend of the greenway. Why? Since they buried Willow Creek, I have to drink stale beer at the Union. And every time I cross Park Street on my way there, my tail gets shorter!"

Photo Copyright 2009 by Ambience Photography

"I'm a friend of the greenway. I commute along the greenway--and if they bury the stream, I'll have to take the bus!"

Read more about the menace of hitchhiking animals!


Which bank reinforcement for our stream?

I've looked into several kinds of bank reinforcement for our stream. Reinforcement is needed to stop erosion that could damage the sewer, threaten landscaping in the ravine or nearby properties, and pollute the lakes. Below I've listed several kinds of bank reinforcement--my first impressions, and certainly not the last word on the subject:

A loose jumble of large stones. While riprap is commonly used in Madison because it's inexpensive, it has numerous disadvantages:
  • Not aesthetic--looks very disordered
  • Not entirely permanent--stones can shift or wash downstream
  • Too thick for vegetation to grow through
  • Bulky for use in tight places
  • Dangerous for children--who can trip or twist ankles

This riprap along the SW Bikeway is an eyesore

Poured-in-place concrete

More costly than riprap, and commonly used in Madison. It can be very permanent, but under some circumstances can shift or crack from freeze-thaw, or from water pressure behind it.

Poured concrete looks like a gutter.

Articulated concrete blocks

Some blocks can be laid by hand, and remain in place because they have interlocking parts. Other systems use blocks linked into large mats by cables. I don't know whether they make small mats, but large mats are laid by cranes--out of the question here. Articulated blocks are inexpensive, and resist cracking and shifting. Some blocks have holes through which vegetation can grow. In photos like this one, usually the vegetation looks ratty.

Natural stone with masonry

Tim Kessenich, owner of a property through which the stream flows, has used this technique. It looks beautiful, but requires some maintenance--for example, when a growing root causes a block to shift. Obviously the labor involved makes this an expensive option. But I think we should get an estimate.

Root wads

A technique recently employed along Pheasant Branch Creek in Middleton (Wis. State J. 8/9/09). The masses of tangled roots from a dead tree are salvaged and moved to the bank that needs reinforcement. I'll investigate this--but it looks bulky and not very aesthetic--and you need a source of roots nearby.

Existing trees

There are a few trees in the ravine growing in the stream bed or very close to it. Trees are nature's way of controlling erosion. So why not leave them, and combine them with other kinds of bank protection? Trees could be damaged during construction, and will eventually die, requiring the gaps to be filled. But leaving them for now could save some construction and landscaping costs.

Which method is best?
In choosing, we have to consider:

  • Cost
  • Future maintenance of stream bed and sewer
  • Aesthetics & landscaping (natural stream curves, vegetation, surface appearance)
  • Damage during construction to existing contours & trees
  • Safety for children

It may be a mistake to limit ourselves to one technique. Let's instead consider a combination. For example, for the stream bed and places where erosion is severe, use articulated blocks. Other problem spots might employ low walls of concrete, or concrete blocks, or masonry--set back as terraces. In much of the ravine not threatened by rushing water, we could plant ostrich ferns donated by neighbors, and irrigate them during dry times with soaker hoses from rain barrels. All these techniques could work around the few trees--close to the stream--which are left in place.

This combination of masonry, concrete, and curves looks good.

I've heard talk of using techniques--like articulated blocks--that allow vegetation to grow through. But photos I've seen usually show ratty-looking vegetation. Remember, our ravine is shady, so not many plants will grow there. We'll have to do some careful landscaping with good soil. Don't just assume that plants are going to look at concrete blocks with holes in them filled with gravel, and say "whoopee!"

For more information on articulated blocks Photo of a crane laying a mat of blocks: www.flickr.com/photos/40020160@N03/3712980141/

Websites: www.ncmaetek.org/Use/acb.html ; http://www.shoretec.com/