Sunday, June 20, 2010

Exploring Historic Channels in Squirrel Hill

Yesterday I went on a mission to look for lost streams. These lost streams once flowed through the area now known as Squirrel Hill in Pittsburgh, but now are re-routed into a combined sewage-storm drain system.

The two streams I searched for are the northeasternmost in this map I posted in my last post:

Historic Drainages of the 4-Mile Run Watershed

My approximate route can be found here.

The creek 'disappears' in the southwestern corner of that route, where I started my walk (downstream/west from there it is relatively natural until Panther Hollow Lake). Upstream from here, Bartlett Road follows its course for about a block


It is hard to tell there, but Bartlett is in a subtle valley.

Murdoch street is a neat street with cobblestone and brick paving that crosses the old channel. You can see the swale where it crosses the road just north of Bartlett.


The channel followed along the current route of Forbes Road for a bit. Forbes and Murray, a major intersection where the Jewish Center and the Squirrel Hill Carnegie Library are located, was near the headwaters of this stream. In this area, the stream probably only flowed during or right after heavy rain or snowmelt.


Looking south on Murray, one of the upper channels was probably in the low spot in the distance.

The intersection of Forbes and Shady is near the watershed divide between the Panther Hollow subwatershed of Four Mile Run, and the Nine Mile Run watershed.


This photo is looking east. Anything over that rise historically flowed into Nine Mile Run instead of Panther Hollow. The underground 'sewershed' is approximately the same to this day.


This little divide on Shady Avenue near Aylesboro Avenue represents the old divide between Panther Hollow and an apparently unnamed little creek that drained the area to the north.

This creek started out flowing down Solway Street.


Solway Street has a lot of open lawns and could be a great candidate for rain garden installation... but many of the garages on the north side of the road, near the original channel, are sunk into the ground, so it would be necessary to make sure flooding wouldn't affect these areas due to poorly designed stormwater management structures.

At this time storm clouds started gathering...


Wightman Playground at Wightman and Solway is sunk into the ground, and appears to be part of the old creek valley.


To my surprise, along the old channel I found one of my old enemies - a tamarisk plant! This plant causes a lot of problems in waterways in the Southwest, and there is a lot of debate over what should be done about it. In this case, the channel is long gone, so the tamarisk can't do anything to it. I doubt it is invasive in Pennsylvania anyway.


Since it isn't displacing native species or salting up the soil in this case, I can look at it notice that it is actually quite pretty. I still had to control an urge to go chop it down.

This channel then used to shoot down a canyon that Beeler Street is in now. It is still steep enough that you can get a feel that it used to have water flowing through it. The whole thing shoots into Carnegie Mellon, which I will explore later.


I walked back to my starting location along a small historic channel that used to shoot up Forbes Street.


In this channel I found... WATER! It turned out that it appeared to be from over-irrigation of a lawn.. but there were some signs of seepage along Forbes Road that could indicate the water table is still near the surface here.

Near the golf course I found a tiny channelized 'stream' with erosion deposits.


I imagine with some sort of modifications, this could possibly be naturalized a bit more... at least slowing the water down before it shoots into the nearby sewer drain.

I made it home before the gathering storm hit. It was another impressive thunderstorm with lots of cloud to ground lightning so I am glad I didn't decide to weather the storm in the park, which I briefly did consider.


The storm seemed significant enough that it probably caused yet another sewage overflow event to occur.
After the storm cleared there was a nice sunset. You can see another storm way off in the distance; that storm did not hit Pittsburgh and went somewhere to the north instead.


So... what is the future of these lost drainages? They are going to have to stay lost for the foreseeable future, since Squirrel Hill was built right on top of them. If you live in this area, you won't be able to see these lost streams again, but you can still restore some of t

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