Better Designs for New Housing Developments?

If you’re shopping for a new home in the country – chances are you’ve run across a typical housing development that many environmentalists say epitomize the problems of urban sprawl. But a recent study says we may be overlooking some unique ways of keeping these developments from threatening the environment. The Great Lakes Radio Consortium’s Tracy Samilton reports:

Transcript

If your shopping for a new home in the country – chances are you’ve run across a typical housing development that many environmentalists say epitomize the problems of urban sprawl. But a recent study says we may be overlooking some unique ways of keeping these developments from threatening the environment. The Great Lakes Radio Consortium’s Tracy Samilton reports:


Joan Nassauer is a landscape ecologist at the University of Michigan. She wanted to see how potential homeowners would react to modified housing developments. Her designs used special methods to keep rainwater from flooding nearby rivers and streams. The flooding can cause erosion, sediment pollution, and loss of habitat. Nassauer created computer models of housing developments that had special systems to catch stormwater and release it slowly into the ground. Her model included existing or re-created wetlands, and the lots were planted with native plants instead of today’s traditional green lawns.


“What we’re ultimately trying to do is mimic the movement of rain water into surface and ground water systems the way it would have been in indigenous ecosystems.”


Nassauer says most people in her study found this kind of development more attractive than traditional lots. She says local officials could pass laws to require developers to use these techniques.


For the Great Lakes Radio Consortium, I’m Tracy Samilton.

Dams Make Major Floods Worse?

  • The Army Corps of Engineers installed these wing dams to force the current to the middle. The rushing water scours the bottom of the channel to keep navigation open. A new study alleges the wing dams slow the current during major floods and cause flood waters to be higher. Photo by Lester Graham.

A recent study concludes that some actions of the Army Corps of Engineers might be causing more, rather than less damage during major floods on rivers in the Midwest. The study by two Washington University professors found that wing dams, which jut out into the river, could cause big floods to rise even higher. The Great Lakes Radio Consortium’s Lester Graham takes a closer look at this study:

Transcript

A recent study concludes that some actions of the Army Corps of Engineers might be causing more, rather than less damage during major floods on rivers in the Midwest. The study by two Washington University professors found that wing dams which jut out into the river could cause big floods to rise even higher. The Great Lakes Radio Consortium’s Lester Graham takes a closer look at this study:

The Mississippi and the Missouri rivers are two of the major arteries for barge transportation in America. Millions of tons of grain, and raw materials are floated up and down the rivers each year. It’s the Army Corps of Engineers’ job to keep the rivers open to barge traffic. The Corps has been doing that job for the past 150 years. But since the 1930’s that effort has taken on immense proportions. Huge dams hold back the river, keeping the water high enough for the barges to travel up and down-stream. Big earthen dikes, called levees, wall in the rivers, keeping them from flooding farms and towns, but also keeping the water from reaching the natural flood plain. Robert Criss and Everett Shock studied flood levels and the effects of the Corps of Engineers projects. Criss says those dams and levees alone might be enough to disrupt the flow of the river and cause flood stages to be higher.

“But the other component is these structures called wing-dams which are jetties of rocks that project out perpendicularly into the channel. For high-flow conditions, these act something like scale in a pipe. They impede the flow, restricting the channel. That slows the velocity of the water down and that also makes the flood stages higher.”

The purpose of wing dams is to force the current to the middle of the river to scour out the navigation channel to keep it open for the barges. Researcher Everett Shock.

“So, they do the job they’re intended to do. It seems that there’s an unintended–perhaps unintended consequence of all these constructions along the river that shows up when we have a big flood and makes it to –on the basis of our study– makes these big floods worse.”

Criss and Shock say their study finds that since these flood control projects have been erected, there have been more big floods, such as the one in 1993 that flooded the Mississippi and some of its tributaries for most of the summer. Robert Criss.

“The fact is, before World War II, a flood stage of 38-feet is very rare and now it happens every five years.”

But not everyone agrees with the methodology used by the researchers. The
Corps of Engineers dismisses the researchers’ study, saying they used flawed data. Corps officials point to a study at the University of Missouri – Rolla. That study compared the 19th century method of measuring a river’s flow by timing how fast floats moved in the current to the methods used today. Dave Busse is a scientist with the Army Corps of Engineers. He says the original stream flow measurements –the ones Criss and Shock used— were inaccurate.

“The flows were over-estimated by 30-percent using this float measurements rather than the measurements than we use today.”

Criss and Shock are skeptical of new numbers that the Corps prefers. Saying it seems awfully convenient for the Corps because changing the numbers makes the historic floods look smaller and therefore makes the 1993 flood look unprecedented. Criss and Shock say based on the original records, there was as much water in past floods as in the 1993 flood but lower water levels. Criss and Shock say the difference between then and now is that the Corps’ big dams, levees, and wing dams constrict the river’s flow and make floods higher.

The Corps, however, has other criticisms of the Criss and Shock study. Dave Busse says the researchers ignored the role of the Corps’ reservoirs in the rivers’ watersheds. Busse says the reservoirs hold back water that would otherwise be part of a flood. And Busse says, another flaw is the researchers conclusions about wing dams. The Corps says the wing dams force water to deepen the channel and increases the flow of the river.

“So, what we have is the same –it’s a re-shaped river, but its carrying capacity is actually higher now. We can actually carry more water at the same stage. The river got deeper, therefore this conclusion that they’ve made is wrong.”

The Corps says there’s more to managing the river than the researchers have considered. Criss and Schock, meanwhile, say their study is not the first to be dismissed by the Corps of Engineers. They say other studies have found similar results, but the Corps dismissed them as well.

Environmentalists have been arguing for decades that levees and dams keep floodwaters from spreading out on their natural flood plains and cause higher flood levels. The Criss and Shock study adds to their arsenal of arguments to change the way the rivers are managed. But most environmentalists concede that we’ve become somewhat dependent on the Corps flood control projects. Chad Smith is with the environmental group,
American Rivers.

“In most ways both of these camps are right. The Corps is right that putting some of the structure in has helped to reduce the kind of annual flood events that always happen on a big river like this, but what they unfortunately have done is to exacerbate what happens when you have bigger floods and the wing dams and the levees and the dams themselves all are part of that.”

The Army Corps of Engineers says it’s reviewing its way of managing rivers in light of the 1993 flood. But they also note that while flood stages might be higher more often than they were in the 19th century, most of the time those floodwaters remain behind the floodwalls and levees, protecting the communities from high water, and the Corps says in the end, that’s the only fact that really matters.

Sowing Seeds to Restore a Wetland

  • This levy currently separates the biggest farm in Illinois (on the left) from the floodwaters of the Illinois River (on the right). The Nature Conservancy is planning to turn the 7,600 acre farm into one of the biggest Midwest wetland restoration projects ever.

Lost wetlands are restored for a number of reasons. Sometimes, they replace a wetlands area lost because of construction or farming. Typically those projects are small in scope. Now a conservation group is looking to create an entire ecosystem in the Midwest through a massive wetland restoration program. The plan is garnering attention from scientists as a new model for how to return land to its natural state. The Great Lakes Radio Consortium’s Jonathan Ahl reports:

Transcript

Lost wetlands are restored for a number of reasons. Sometimes they replace a wetlands area lost somewhere else because of construction or agriculture. But typically these projects are small in scope. Now a conservation group is looking to create an entire ecosystem in the Midwest through a massive wetland restoration program. The plan is garnering attention from scientists as a new model for how to return land to its natural state. The Great Lakes Radio Consortium’s Jonathan Ahl reports.


(Ambient sound – the farm)


Tractors are rolling across the Wilder farm in Central Illinois, tending to fields lined with rows of corn and soybeans. This plot of land is 76-hundrd acres, or nearly twelve square miles. It’s the biggest farm in the entire state. But it won’t be a farm for much longer. The Nature Conservancy has purchased the land, and hopes to make the area one of the biggest Midwest wetland restoration projects ever. The group hopes the Emiquon Wildlife Refuge will make improvements to the land ranging from creating a new stop for migrating birds, to improving the quality of the Illinois River that is the source of drinking water for hundreds of thousands of people. Joy Zedler is an Ecology Professor at the University of Wisconsin. She says the size of this project creates a unique opportunity to reintroduce extinct plants once native to the area.


“If you have a wetland the size of this table, and you want to restore an endangered species, very likely you wont be able to find the right conditions to support it. But if you have 7600 acres, somewhere in that site may well be the combination of conditions that can support that species.”


Zedler says bringing native plants back to the area can provide food and habitat for a variety of animals and insects that were once native to that region, and improve the health of the region’s ecosystem for miles in every. One major advantage Emiquon has is the entire farm is surrounded by a levy. That means one hole in the levy could allow the area to be a contained flood plain for the river. Rip Sparks is a professor at the University of Illinois. He says allowing that to happen has the potential to bring a wide variety of plants and animals back to the river area. That’s because it would create a seasonal flood plain.


“The spring flood lasts long enough that the organisms have adapted to utilize it for spawning and feeding areas. And the birds have used it as feeding areas as they make their migrations. So it seems very important that river be connected to the flood plain.”


But not everyone is excited about the plans to turn Emiquon into a wetland. Tom Edwards is an activist who has studied the Illinois River region for decades. He is one of several environmentalists that say all of the excitement about the project is mis-founded. Edwards says the waters of the nearby Illinois River are so polluted, that if one drop becomes part of the Emiquon site, all the talk of reintroducing native plant and animal species will become moot.


“Nothing on the Illinois River has any vegetation on it. It’s a toxic waste. The fish can hardly survive. If they let the river water in, it will create another mud hole. It’s not a way to cleanse the river, and we would lose a valuable asset for the future.”


Edwards says Emiquon can be a separate, stand alone lake that protects some wildlife and plants. But he says it will never be the grand experiment in wetland restoration that some claim it will be. Many scientists counter Edward’s argument by pointing out that wetlands can be excellent filters for pollutants, and improve the quality of nearby bodies of water. And the Nature Conservancy says it is aware of the challenges of creating a wetland so close to a less than healthy river. And that, says the Conservancy’s Michael Rueter, is what makes this site ideal. Because it’s enclosed by levies, whatever is done here can be reversed. If opening the site to the river causes problems, the levy can simply be closed up again, and something else can be tried.


“Any action that we take will be reversible. So we’re not taking down levies or lowering the heights of levies. Because we want to be able to reverse this and adapt as we learn more information.”


Rueter says one option would be to install a gate in the levy, so they could control the amount of water that comes into Emiquon. Scientists could than closely monitor the effect of adding River water to the site. Reuter says the Nature Conservancy hasn’t decided how it will approach restoring the site just yet. The group has time to think about it. Part of the purchase agreement gives the former owners the right to continue to farm the land for up to five more years. But when it does become a restoration project, it will likely have the attention of activists and researchers around all of the Midwest. For the Great Lakes Radio Consortium, I’m Jonathan Ahl.

SOWING SEEDS TO RESTORE a WETLAND (Short Version)

  • This levy currently separates the biggest farm in Illinois (on the left) from the floodwaters of the Illinois River (on the right). The Nature Conservancy is planning to turn the 7,600 acre farm into one of the biggest Midwest wetland restoration projects ever.

A conservation group is planning a wetland restoration project that will be one of the biggest ever in the Midwest. The Great Lakes Radio Consortium’s Jonathan Ahl has more:

Transcript

A conservation group is planning a wetland restoration project that will be one of the biggest ever in the Midwest. The Great Lakes Radio Consortium’s Jonathan Ahl reports:


The Nature Conservancy has purchased the biggest farm in Illinois, and is planning to convert the land into a wetland. The seventy six hundred acre plot of land in Central Illinois is attracting attention from researchers from around the region. Joy Zedler is an Ecology professor at the University of Wisconsin. She says the project will be significant.


“That fact that it is large already puts it on the map. And the fact that we could experiement with reintroducing rare species and finding the conditions that facilitate their growth is exciting.”


The Nature Conservancy is facing some challenges with the project that is less than a half a mile from the Illinois River. Critics say the polluted waters of the river will make it nearly impossible to recreate a natural wetland. For the Great Lakes Radio Consortium, I’m Jonathan Ahl.

Wetlands Sedimentation a National Problem

Conservation agencies are having a tough time correcting one of the
worst problems in some on the most sensitive areas. The Great Lakes
Radio Consortium’s Lester Graham reports on the damage sediment and silt
have on wetlands: