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Showing posts with label Dam Removal. Show all posts
Showing posts with label Dam Removal. Show all posts

Sunday, April 12, 2015

Grass Roots Science Denial Blocks Dam Removal

Science denial is not the exclusive realm of global climate change.  A recent proposal pitched to a neighboring township by a local conservation organization to remove a 111-year old concrete dam was met with a very vocal outcry from locals who want things to remain just as they are.

Here is the link to the newspaper story about the township's decision last month. And here is my perspective:
Wehr's dam and Wehr's Covered Bridge, South Whitehall Township, PA
(photo credit: mcall.com)

Last year, the Wildlands Conservancy, a local non-profit group proposed to South Whitehall Township’s Board of Commissioners conducting a feasibility study on removing Wehr’s dam on the Jordan Creek in South Whitehall.  Wehr’s dam was built at the beginning of the 20th century to power Wehr’s grist mill, which had stood nearby but was demolished decades ago.  A covered bridge, which also bears the Wehr name, is still in use 150 feet downstream from the dam. The township created a park centered on the aesthetics of the dam and covered bridge.  The Jordan Creek is a popular trout stream which is stocked by the state. But there is really no chance for a native population of trout to subsist in this spring-fed creek, because the dam causes the water in the Jordan to back up, stagnate, and warm up to summer water temperatures that trout cannot tolerate. The South Whitehall commissioners approved letting Wildlands carry out the feasibility study. But even at that preliminary step, a local blogger who thinks he has an axe to grind with Wildlands Conservancy began crying foul and riling up the opposition with accusations that Wildlands practices junk science. Interesting how people who cannot, or refuse to, understand science often resort to claims of junk science or academic dishonesty. In addition to the blogger, some descendants of the Mr .Wehr who built the dam began a petition drive seeking to prevent the dam’s removal.

I heard only one rational voice opposing the dam removal. My friend Mike Siegel questioned whether the Jordan Creek, in the absence of the dam, would carry enough water during summer low flows to sustain a population of fish. That’s because, depending on local groundwater conditions, it’s not unheard of for steams flowing over limestone bedrock to sometimes disappear into a sink hole and re-emerge further downstream out of another sinkhole.  When that happens to a steam, the fish usually just hunker down in deep pools in segments of the creek that have water in the summer months. I didn’t take the time to drive to the South Whitehall municipal building to read the feasibility report put together by Wildlands Conservancy and their engineering consultant. So I’m not sure whether the bedrock hydrology was even considered in the report.  But I don’t think trout would be likely to get stuck high & dry by a temporarily disappearing stream. That’s because trout will always seek out the coldest water, which, in an area underlain by limestone, would be wherever the nearest spring is feeding the creek. Based on the emotional outcry of people opposing the dam’s removal, it doesn’t sound like the stream’s hydrology even figured into the decision by the township Commissioners to turn down Wildlands’ offer to remove the dam at no cost to the township.

While it's refreshing to see commissioners consider residents' wishes in a decision, I think four of these five commissioners voted based on sentiment rather than facts. In this case, a non-profit organization with proven experience in removing low-head dams was offering to remove this mass of crumbling concrete at no cost to the township. Turning away "free" money to remove a financial liability like this deteriorating dam was an irresponsible vote that will cost the South Whitehall taxpayers plenty when they are facing with removing the failing structure in the future.  With this vote, the commissioners chose to blatantly disregard science in favor of a nostalgic alternative reality that the most outspoken people attending the meeting that night wanted to believe.  In doing so, they voted to commit their taxpayers to fight a losing battle against the natural deterioration of pile of rocks and concrete blocking a good trout stream that could be a better trout stream.

The ‪Wildlands Conservancy's study included an underwater survey of the dam, which is not part of the PA Department of Environmental Protection’s routine dam inspection program. So with new data that proved their dam is in poor repair, particularly below the waterline where it is more difficult to monitor, it seems that the majority of residents who weighed in still sided with their emotions rather than science. It seems very much like the climate change stalemate in the U.S. If some people cannot see something, particularly something abstract, they won't believe it. Not even if scientists and engineers have verified the risks.  Here is my favorite line from the Morning Call story:

"The rest of the board sided with Commissioner Glenn Block, who said he wasn’t convinced by the findings that removing the dam wouldn’t increase flood risk."
  

Wehr's Dam, with sign warning, "Danger Dam - No Boating, No Swimming, No Wading." (photo credit: Wildlands Conservancy, as published on LehighValleyLive.com)
I don't know Mr. Block's professional background, but he appears to be neither a scientist nor an engineer. And he clearly doesn't want to allow science to interfere with his political popularity. So actually, South Whitehall's commissioners had the opportunity to do the right thing, although the right thing (IMO) in this case would have been unpopular with the standing room only crowd. So their commissioners voted 4-1 to keep their heads in the sand despite having been shown the risks and having been given an opportunity to avoid the financial burden of maintaining a deteriorating dam indefinitely into the future.  I live in neighboring Lower Macungie, so at least my tax dollars won't have to pay for the extensive maintenance. Or the potential law suit when someone is injured as a result of the dam. I wonder if the Wehr family would be so insistent about no removing the dam if they still owned it and were responsible for the dam’s maintenance costs and liability.

Monday, September 2, 2013

Does a Riparian Buffer Belong in a City Park?


Allentown’s Morning Call recently published an Op-Ed piece written by local blogger Michael Molovinsky, who has a passion for preserving historic structures in the city’s renowned Lehigh Parkway. Lehigh Parkway was the beneficiary of a number of Works Progress Administration (WPA) projects during the 1930s, with various massive stone bridges, fountains, walls, and stairs remaining in various states of repair.  So there are plenty of historic structures in Lehigh Parkway for residents to take pride in and care for.  In my mind though, the most prominent feature of Lehigh Parkway is the Little Lehigh Creek, which the Parkway follows for about three miles through the city.

Little Lehigh Creek in Lehigh Parkway
(photo credit:  wikipedia.org)
In his Op-Ed, Molovinsky blasted a riparian buffer restoration project planned for Lehigh Parkway and denigrated the efforts of the Wildlands Conservancy, a local non-profit engaged in ecosystem restoration and preservation.  Wildlands obtained the necessary permits and outside funding to replant riparian buffers along the Little Lehigh in the Parkway. Volunteers from the Little Lehigh Chapter of Trout Unlimited, of which I am a member, will assist with replanting the buffers.

Molovinsky implied that Wildlands is a special interest group trying to hijack Lehigh Parkway for riparian buffer experiments that would compromise the public’s view of and access to the creek. He said that the function of a riparian buffer is to filter fertilizer from rain runoff and from entering the creek and lamented that current streamside buffers are nothing more than strips of weeds that block the view of and access to the creek.  This is a shortsighted accusation, however, because riparian buffer restorations have been proven to improve the health of streams.  A healthy riparian buffer of 50 feet or greater would typically include various native plants, shrubs, and trees. They would absorb stormwater runoff to mitigate flooding, shade the summer sun to keep the spring-fed waters cool, and provide habitat for various insect species that will be a food source for both fish and birds.  A properly restored riparian buffer would indeed be aesthetically pleasing rather than the weedy eyesore envisioned by Molovinsky.

Dog in Lehigh Parkway. Most, but not all, dog owners
clean up after their pooches.
(photo credit:  http://www.delawareandlehigh.org)
The neatly mowed stream banks that Molovinsky idealizes allow sediment and pollutants, including geese and dog feces, unchecked access to the Little Lehigh, which is a drinking water source for the city of Allentown and some of the surrounding areas west of the city.  A drinking water source for well over 140,000 people, and Molovinsky is worried about a riparian buffer impairing the view of the creek?

With designated pathways mowed through the riparian buffers, the public could still access the stream, the buffers could still perform their intended functions, and the diverse ecosystem that thrives in a healthy riparian buffer could re-establish itself.  A healthy riparian buffer begets a healthy stream.

In addition to his Op-Ed stand against riparian buffer restoration, Molovinsky's blog also trashed a related effort by Wildlands Conservancy to remove two dams in Lehigh Parkway. Wildlands had obtained the necessary permits from the Pennsylvania Department of Environmental Protection (PADEP), the state body in charge of dams, to remove these two dams. They had the green light from the city’s parks department to remove these dams, which cause the water to slow down and sediment to build up behind them.  But at the 11th hour, Molovinsky tried to block removal of one of the dams, located just 18 feet downstream from the WPA-built Robin Hood Bridge, claiming without basis that removal would cause stream-bed scour that would undermine the bridge and cause it to wash out. Just days ago, however, following a public hearing by city council, Allentown’s mayor gave his approval for the dam removals after it became clear that Wildlands had done the proper engineering due diligence to rule out any adverse effects on the Robin Hood bridge from removal of the adjacent dam.  More obsolete dams have been removed in Pennsylvania than in any other state.  Why would PADEP have approved the dam removal if the effects on any nearby structures had not been properly evaluated?

Come on, Michael.  Environmental folks and history buffs need to work together to protect special places from the effects of over-development and urbanization.  We should not be at odds unnecessarily over things like removing detrimental dams and planting protective riparian buffers.

Joggers in Lehigh Parkway (photo credit: Express Times)
Nostalgia is tricky.  It can cause us to myopically yearn for a distant, simpler, and more picturesque time.  But 21st century scientists and anglers recognize that riparian buffers and dam removals are the key to the health of any stream.  In environmental science, just as in medical science, we are fortunate to have advanced far beyond common practices of the mid-1900s.