article on the development of northcentral PA streams

[k-bob]

posted a less detailed version of this in another thread. this version has clear figures giving examples of stream development from logging to recent floods. worth looking up some geology terms to get a few of the ideas here imho ... scene in fig 25b for ex would have been lost on me, very interesting

https://gsw.silverchair-cdn.com/gsw/Content_public/Journal/geosphere/12/1/10.1130_GES01180.1/4/305.pdf?Expires=2147483647&Signature=FBU0iIsPUB~fWooZCI6Zdd7qG5~vDlkwROfouFc7aEfY0OxJkuYhHl0zt~B1LZhkVEWIwiFvUtDT6DEUTzAQfquc0rQ2RX67AVkBrJppB9Hl8473B5J27kd3M0eBMhgiUchchXcblYAQrjiDz0P2bqGjw6SJtyMP950u-gKM6cmCtU3-tTTX96OFUMc2-J2WdJ4kI1dMaSkvWUqhiGA1y0TTTmCJYc4fvmw6K5cAMFOX-ewyA1cL9utj7zRi57iLRzsh-uZq8LUrmOI-AjlH2cEReBRn-kGoa9RZX3ceOwTzp8Tci9ZA5YBSk2HJyLs9rwWhLC7AyD2L-44exB9B4g__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA

btw can look up any place in pa in the lidar land contour map that is used in in figure 19 easily here:

http://maps.psiee.psu.edu/preview/map.ashx?layer=1247

 

[troutbert]

Bob, thank you very much for posting this.

Very good stuff. I saved it and will read the whole thing.

 

[Tups]

Kbob thanx very much for finding and posting this study. I had hoped that after Lee someone would be studying the rivers hit so hard in that region. I haven’t read the entire paper or digested it yet. Hope to do so soon. I recall that USFWS had spent a small fortune “restoring” a trib to Loyalsock using essentially Rosgen techniques in 2010 I believe it was. This study describes why that project failed without mentioning it by name. Also, though It may not be specifically highlighted, I believe this paper describes the “channel evolution model” fairly well. Apologies to Dave Putnam and the USFWS. It is not my intention to attack that agency because they do some very good work, but hopefully a lesson was learned concerning attempts to control channel forms in fluvially very active watersheds.

 

[troutbert]

One of the important points made is that the streams in the region are naturally multi-channeled systems, not single channeled.

I think most of the public, including most fishermen, and many involved in stream projects and land management in general don't know that.

Most people seem to hold a strong assumption that streams are "supposed" to be in a single channel.

I've seen channel blocks out on the forested streams, no doubt installed by well meaning people.

 

[Tups]

Tb. Yes, the streams in NC Pa are naturally anastosed, anabranched and multichanneled; all of the above. And I think we can safely say that plan form occurred in response to the massive disturbance caused by the melting glacier which covered the region. The channels are still moving and sorting the sediment and bed load caused by that long event. But the good news is that brook trout are well adapted to this high energy, moderate to high disturbance environment. In the long term these catastrophic floods are beneficial to brook trout life history.

 

[k-bob]

supplemental files, w/ great images and discussion for one stream at a time, are linked in this version

https://pubs.geoscienceworld.org/gsa/geosphere/article/12/1/305/132296/?searchresult=1#tab-SupplementsCss

need a fast (!) connection to download these (took minutes to get the full fishing creek one and I have reasonably fast internet) but it was well worth it. great images and explanation.

I had some idea of the extent of stream modifications for 1880-1920 log drives (as one slide notes, logging berms along streams are common in the area and can be seen in lidar (OP link))... but I did not realize the role of sediment released by logging-era floods in altering NCPA stream channels in an ongoing way.

article linked here is on lycoming/ muncy/ loyalsock/ fishin' creek, exec summary of this report on kettle drainage mentions similar stream structure issues w/ sediments from logging era floods:

http://www.kettlecreek.org/uploads/2/5/6/0/25607137/upper_kettle_creek_fish_habitat_plan.pdf

 

[troutbert]

One puzzling aspect of the excess sediments from the logging era thing is that there are long stretches of stream that are incised down to bedrock.

If the excess sediment was so overwhelming, wouldn't you expect the channels to be aggraded, rather than incised?

It may very well be that there are excess sediments left over from the logging days, but is there anything that can be done about that?

Regarding the berms, rock walls, old railroad grades, and road grades that are constraining the streams and separating them from their floodplains, these can be removed.

In many places what appear to be berms are actually old logging railroad grades. Which have the same effects as berms and walls when they are located along the stream, separating it from its floodplain.

Get rid of them! All it takes is a guy with a backhoe.

 

[Tups]

Tb. Those reaches of incision to bedrock all occur in the headwaters Tributaries to the four main rivers under study. The hypotheses of the work is that the sediment was stored in the system prior to TSLee. Those stored sediments were the result of the logging era. When the hill slopes were stripped bare massive amounts of erosion occurred. That debris came to rest on the earlier terraces and flood plains. The authors believe that these logging sediments are primarily the materials being moved downstream in regular pulses by recent floods. Because the hillslopes are now heavily vegetated, sediment is no longer available from this source. As a result, a flood of this magnitude and stream power is more likely to remove sediment from the headwater channels depositing it downstream. In many case apparently the energy was sufficient to remove all of the bedload down to bedrock. Without substantial new sediments entering the headwater streams and their riparian zones, these bedrock streams are no doubt here to stay.

 

[lycoflyfisher]

This study provides some valuable information for post flood characteristics of many North Central watersheds and may provide valuable insight to regulators, resource agencies and municipalities as they respond to significant flood events.

Regarding bedrock exposure on the streams listed in the report the headwaters of the mainstem of each main creek in the study has sections where the stream has cut to bed rock.

 

[k-bob]

can find other places where streams appear to have left berms and reverted to older channels ... (bowmans creek south of RR grade in pre-flood lidar contour and post-flood satellite image)...

as the article notes, also may see some rough erosion and channel widening in flood area tribs...

 

[Tups]

Kbob. Again. Interesting images. I believe the stream (Bowman’s cr) is flowing from left to right. Is that correct? It’s not always evident.

 

[k-bob]

Yes flow is left to right, stream appears to have reverted from large-looking bermed channel.

 

[troutbert]

k-bob, thanks for posting the very interesting images.

This is referred to as a meander cutoff.

https://en.wikipedia.org/wiki/Meander_cutoff

This is part of the normal dynamics (changes) of stream-floodplain systems.

I have seen the types of channel shifts described in the study during other floods as well.

Those floods were large floods, but not nearly as large as this one, which was the largest flood ever recorded in the Loyalsock drainage.

The point being that these types of changes occur pretty commonly during flood events. They are normal events. And they are important ecologically.

Floodplains have such a great variety of plant and animal species because these dynamic changes create a great variety of habitats.

 

[Tups]

Kbob. In the lidar image I see the old RR grade running in a straight line across the top of the image. The PGC uses this as a SGL access road now. I also see a large berm constructed parallel to the outside bend of the meander likely intended to halt the process of cut and fill alluviation, which is how stream channels move under normal circumstances. Either the RR or the PGC would have constructed the berm to protect the roadway from erosion. Do we agree on this interpretation?

 

[afishinado]

troutbert wrote:
k-bob, thanks for posting the very interesting images.

This is referred to as a meander cutoff.

https://en.wikipedia.org/wiki/Meander_cutoff

This is part of the normal dynamics (changes) of stream-floodplain systems.

I have seen the types of channel shifts described in the study during other floods as well.

Those floods were large floods, but not nearly as large as this one, which was the largest flood ever recorded in the Loyalsock drainage.

The point being that these types of changes occur pretty commonly during flood events. They are normal events. And they are important ecologically.

Floodplains have such a great variety of plant and animal species because these dynamic changes create a great variety of habitats.

^Thanks for the info.

I have a cabin back in the area of the Bowman's Creek headwaters.
The flood you mentioned had an astonishing effect on Bowman's changing the stream completely overnight in many sections.

After knowing the forest and stream for most of my entire life, growing up in the area, my first time back in there after the flood it was like a totally new place, unrecognizable.

Here is a post from 2011 Bowman's Flood 2011

 

[troutbert]

afishinado wrote:

I have a cabin back in the area of the Bowman's Creek headwaters.

Can I stay overnight there? I love that area.

I'll sweep the floors and mow the yard.

From your photos it looks like the roads were badly damaged.

Did they rebuild / relocate the damaged sections of the roads?

 

[k-bob]

Tups yes, the idea that this may be a bigger berm to protect rr makes sense to me. Then maybe in big flood(s) the stream moved back to an old channel that is further from the rr than the bermed channel is?

Tb Yeah I'm a fan of that area I've driven that road several times and but never seen a bear I always expect to

 

[afishinado]

troutbert wrote:

afishinado wrote:

I have a cabin back in the area of the Bowman's Creek headwaters.

Can I stay overnight there? I love that area.

I'll sweep the floors and mow the yard.

From your photos it looks like the roads were badly damaged.

Did they rebuild / relocate the damaged sections of the roads?

:lol:

The roads have been rebuilt for the most part, but many sections of the stream bear little resemblance to what they were before the storm. At the time it was devastating, but now it's very interesting to see the changes to the stream as well as the riparian forest.