Kleiner's Blog

(This is the tenth park log of 2012 – get caught up with the links at the bottom)

There is no easy way to say what I am about to say to lifelong Allentonians.  I’m just going to say t without disclaimer or preparatory comment. Muhlenberg Lake has got to go.  It is unlikely to go this year or even in the coming years but I assure you, the consequences of its continued existence will worsen over the next decade and Muhlenberg Lake will have to go. 

In the early 1900’s there existed no standing body of water where the “Lake” is today.  A Depression Era project saw Cedar Creek dammed and the now existing Lake created.  It is more than highly unlikely that a Field Biologist or Environmental Scientist was on hand to guide this construction and, even if they were – it would likely not have mattered.  Science has come a long way since then and I can tell you, scientifically, that lake should not exist.

Cedar Creek is a shallow, fast moving body of water.  The particular ecosystem that such a creek creates for itself a unique and variable equilibrium in combination with the organisms that inhabit it, the riffles, runs and pools that characterize it, the plants that live on its streambanks, the organisms that find their niche in those plants, and the entirety of the creek’s surroundings for miles.  In other words, left undisturbed the entire ecosystem is governed by a negative feedback loop; meaning, that whatever enters the ecosystem is equal to that which leaves it.  What goes in – goes out, everything is maintained and no loss or gain occurs.

Now, consider what would happen to that delicate balance if a lake was created somewhere along the course of the stream.  The balance is lost.  In nature, lakes and still bodies of water (stream-fed or otherwise) are part of natural processes that, as they happen, maintain the feedback equilibrium that I described above.  A man-made lake with almost zero circulation? There is no natural process that could account for that degree of disturbance.

One of the pro-lake arguments that you may hear around Allentown calls for a remodeling of Muhlenberg Lake that would see a proper circulation introduced.  Folks, such a stop-gap measure might reduce the accumulation of stream sediment and the growth of algae but it would not help the health of Cedar Creek as it heads on to meet the Little Lehigh.  Even if the infamous land bridge would be removed, the circulation would not change greatly.  You cannot stretch a six foot wide creek to the width of a lake and maintain the same rate of speed.  That’s what is important here, the loss of speed.

There are many reasons why such a new system of circulation would not help but perhaps the most significant involves temperature.  As water from the creek enters the Lake and its speed is greatly reduced, the water is longer exposed to sunlight.  When the water warms, the organisms that inhabit it from invertebrates to fish are affected so detrimentally that some of them – perhaps many of them, will die.

Think about what happens to the water then.  It is warmer, full of nitrogen, ammonia, and methane from all the decomposing organic matter.  The Lake becomes a smorgasboard for algae – so much so, that the City of Allentown has to hire individuals each year to free the waters from algae.  As algae blooms, the water loses its dissolved oxygen and contributes to further loss of aquatic life.  Here, begins a positive feedback loop that ends in eutrophication.

Consider also the sediment from the Creek that builds up in the Lake as the speed drops significantly.  Muhlenberg Lake has had to be dredged many times in its past and as you can see from the standing Geese below, the sediment has become very high again.

That hypoxic junk water leaves the lake and meets the Little Lehigh near MLK Boulevard.  What do you think happens to the Little Lehigh when that sickly stew comes pouring in?  The Little Lehigh is a source of drinking water for the City of Allentown.  The dirtier that water is, the more money is required to clean it.  Whatever water doesn’t head in for treatment continues on to the Lehigh River.  Everything in Nature is connected folks.

Despite drawing the ire of residents of the City of Allentown, I must suggest and must continue to suggest that this Lake meets an overdue end as soon as possible.  A proper ecological restoration should occur to return the stream to its natural boundaries and a wetland should be created in the space around it where the Lake was.  The other valid option would be to reroute the stream around the Lake and make sure that the water in the Lake never reaches the stream.  Thing is, this is a very flood prone floodplain.  I do not think this solution is an ecologically viable one.

Many similar projects across the country have been undertaken because of man-made lake like ours.  This is not a foreign concept or a new one.  It is the logical course of action and the action that needs to be taken.

Park Logs 2012:
1. Cedar Creek Parkway 1. : The LCA destroyed everything.
2. Cedar Creek Parkway 2. : Well, They never paved the Rose Gardens…
3. Lehigh Parkway 1: Erosion, Erosion, Erosion )
4.  Lehigh Parkway 2: The Proof is on the Stream Banks
5.  Parkway 3:  This is Bad. Very Bad.
6. Jordan Park: What I was surprised to find
7. Winter Woods and Rain at The East Side Reservoir
8. A Smack in The Face at Canal Park
9. Thanks Harry, at Trexler Park