Walking Very Marginal Stocked Streams in Fall

[JeffP]

I always enjoyed this. Its cool to see the survivors that lasted the floods and drought. I grew up on Middle Creek (Lancaster County) and would always see a dozen survivors in a 1/4 mile stretch. One year a friend caught a 24 inch brown in the fall. I took a short walk this past weekend and didn't see anything but I wasn't wading and the sun angle was tough. Even the bridge pools usually had a couple left. Speaking of bridge pools, upper Middle Creek has had most of its bridges replaced and all the nice holes are gone. Most of these bridge holes could take 5-6 buckets and accommodate 10 anglers with good water on both sides of the bridge. I'm not sure if its new methods. It is true that some of these holes had fairly small dams built on the downstream side.

 

[John96]

Interesting observations.

The 'natural' history of these marginal stocked streams is actually kind of interesting to me. What happens ecologically once a few buckets of fish make it into the stream? It makes good food for thought. There's not too much info out there.

 

[troutbert]

JeffP wrote:

Speaking of bridge pools, upper Middle Creek has had most of its bridges replaced and all the nice holes are gone. Most of these bridge holes could take 5-6 buckets and accommodate 10 anglers with good water on both sides of the bridge. I'm not sure if its new methods.

I've also noticed the general pattern that old bridges generally have better bridge pools than new bridges.

I think the main reason is that the old bridges had narrower spans and the new bridges usually have much wider spans.

With the narrower spans the flow of the water was much more concentrated during floods, so the velocities were high, so deeper pools were scoured down into the streambed substrate.

It's a similar scenario with replacing old school culverts with wider box culverts. It's better for fish passage. But not as good for pool creation.

Here's a design challenge for all you civil engineers out there. Design bridges and culverts that meet these criteria:

1) Good fish passage.

2) Good pool creation.

3) Good grade control on the upstream side. (Very often streams are highly incised upstream from bridges.)

 

[Dave_W]

troutbert wrote:
I've also noticed the general pattern that old bridges generally have better bridge pools than new bridges.

Yep, me too.
Lots of bridges have been replaced lately in my neck of the woods and they all were better (for fishing) before the changes.

 

[Dave_W]

Walking local stocked trout streams was something I used to do and have got away from. I'd like to return to this and have been hoping to walk some local streams sometime this fall.

Most of the ATWs where I've done this are very marginal and often no trout are visible at all in the fall. During early to mid summer, they can be loaded with stockies as local angling pressure on these trout streams just about vanishes by Memorial Day and a lot of fish survive. By October, however, they have usually all but disappeared due to the low and warm conditions in late summer.

Hopefully some folks will read this thread, go walk their local stocked streams, and report back what they have seen.

 

[Acristickid]

I have seen several holdovers above a delayed harvest area that gets too warm to fish at times. Lately I have scouted a small stream that flows into a lake- looking for spawners with these rains.

 

[lestrout]

Great discussion here on several fronts. Regarding the pool structure as a function of old vs. new bridges: might the very age of the old bridges be a factor? Over time, there would be high water and flood events, and hard structures like huge rocks and bridge supports would have bed erosion below them. This erosion would deepen the pools.

 

[CLSports]

Bridges are something I know a little bit about.

In a nutshell; widened Bridges and Culverts are necessary where the increased storm runoff has caused, or may cause, upstream flooding events. When excessive water backs up at a bridge or culvert it will restrict the water flow in flood events and the upstream properties will be flooded or it may over top the road surface in some cases. Therefore most new structures need to be widened to meet the hydraulic requirements of the DEP.

The stream bed and channel are most times not affected with bridge replacements. The new structure requires rip-rap to be added around the base of the structure to prevent further erosion of the abutments, piers or culvert openings.

The existing pools and scour areas are not changed, but surely over time the scour will be lessened as was stated above. Streams constantly change and new pools are being created and filled in with every storm event every year. If anyone has fished any stream long enough you will recognize how much it changes over the years and not necessarily from any new structures, just the forces of nature.

Creating a scour hole can be as easy as having a large tree fall in the water. They don't need to be designed. Mother nature does that just fine.

As engineers, we need to consider the safety and well being of the human population over the little fishies, but rest assured that they are taken into consideration. Probably more so than you would think.

 

[foxfire]

I too often walk "stockie" streams in my area come fall. I'm always surprised the number of holdovers I see. It's a wonder why the Fish Commission doesn't stock a better strain of trout whereby natural reproduction may occur. Many of these local stream are very fertile and have great habitat. Obviously there must be plenty of thermal relief for the trout over the summer.

 

[PennKev]

foxfire wrote:
It's a wonder why the Fish Commission doesn't stock a better strain of trout whereby natural reproduction may occur. Many of these local stream are very fertile and have great habitat. Obviously there must be plenty of thermal relief for the trout over the summer.

Virtually ever watershed in the state already has wild trout were conditions and habitat allow. The lack of wild trout indicates, to me, a deficiency in habitat that may not be apparent to casual observation.

Holdover fish, in my experience, are not a reliable indication of habitat suitable for reproducing wild populations. I know of streams that will holdover fish for two or three years, and then the next two years will be particularly dry and hot and have virtually no holdovers. Even if a wild population were to take root, it would likely be wiped out or perhaps so suppressed so that trout are only a niche species.

A trout stream is only as good as it's worst day/month/year.

 

[foxfire]

A trout stream is only as good as it's worst day/month/year.

The point was In the past 10 - 12 years I've never seen these streams as low and/or warm as they have been the last two years and yet the trout survived.

One such stream has had much habitat improvement as well as elimination of most headwater septic systems. Perhaps it's on the mend.

 

[troutbert]

PennKev wrote:

Virtually ever watershed in the state already has wild trout were conditions and habitat allow. The lack of wild trout indicates, to me, a deficiency in habitat that may not be apparent to casual observation.

I agree. If the conditions are right for wild trout, the wild trout are already there.

There may be exceptions to this, but those are probably extremely rare.

 

[JeffP]

So I couldn't resist. I drive past the bridge over Middle Creek on Clay Road every day. I've thought about stopping every day but haven't done so yet this year. 1st peep over the downstream side of the bridge and a nice stocker brown right in plain site. Old narrow bridge and deep whole on both sides. A spring runs in just upstream. May have to go try to catch him!

 

[jacob]

Get out there! Whaddya waitin for!

 

[troutbert]

lestrout wrote:
Great discussion here on several fronts. Regarding the pool structure as a function of old vs. new bridges: might the very age of the old bridges be a factor? Over time, there would be high water and flood events, and hard structures like huge rocks and bridge supports would have bed erosion below them. This erosion would deepen the pools.

No, it's not a matter of time.

Many of these wide span bridges have been around for 30 or 40 years, and pools have not formed. And they won't form, for the reason already explained.

 

[JeffP]

I'm not sure where examples of these(older wide span) are. It seems like in the old days, every bridge pool was great. I'm talking more about smaller streams. I guess if you think about it, they are artificial. But still.

 

[Mike]

The trout may survive a warm summer, but the viability of their gametes may not.

 

[troutbert]

JeffP wrote:
I'm not sure where examples of these(older wide span) are. It seems like in the old days, every bridge pool was great. I'm talking more about smaller streams. I guess if you think about it, they are artificial. But still.

On Middle Creek you saw the old bridges, which had good bridge pools. And now you see the new bridges, which do not.

What design differences have you noticed between the new and old bridges?

 

[JeffK]

A design trend in bridges is that materials have gotten cheaper and labor more expensive (over simplified of course). Most modern bridges are based on over- designed I-beams that can handle a wide span between concrete supports. Plenty of steel in those I-beams, but they are quick to design and easy to install. Really old stone bridges couldn't handler large spans so they had narrow openings that accelerate the flow. Plus, small towns couldn't afford to do giant stone bridges like the Starruca viaduct built by the Erie RR. It was possible to do incredible stone work, but most places couldn't afford it.

Around the Civil War iron bridges started to come into use and later steel. The first iron bridges duplicated wooden bridge trusses, but in the late 19th and early 20th century all sorts of crazy truss designs came into play to save materials because small towns couldn't afford much (plus the spans weren't that wide). Height and width of most bridges until less than 100 years wasn't all that scientific. Built it where locals thought highest flood was, and if it got swept away you rebuilt it 5 ft higher. Repeat until it doesn't get swept away.

Just saw one of the old RR bridges over the Delaware in Easton with my brother who is an old bridge fan. It had riveted box beams that most have taken an incredible amount of labor. That isn't done anymore.

Old bridges were narrow by a combination of high material costs and low budgets. For most of our history rural areas were poor and tried all sorts of small bridge ideas to save money. American ingenuity was in full flower with bridge design to meet local needs. Now we just use giant I-beams and over design it so the stream isn't as narrowed. Most highway bridges have gotten pretty dull IMHO.