Letort, Cumberland Co., 9/06/19

[Dave_W]

Spent part of the morning and early afternoon up in the FFO section. I hiked/fished from the Bonneybrook Bridge down to I81.

WEATHER: Very nice; high 60s-70s, partly sunny.

WATER: Crystal clear, strong flow, 54 degrees F (confirmed by thermometer).

INSECTS/HATCHES: None. No rises seen.

All things considered, Letort, like other CV streams, looks very good these days. The flows are stronger than I can remember and many areas that used to be sediment laden are now gravel bottom. The stream looks good. Some of the work by CVTU in the upper area is promising. Bankside vegetation is lower than it was earlier in the summer the last time I was there, but still extremely dense. Many meadows that I could easily fish back in the 1980s are now essentially inaccessible due to high water up in the canary grass and swampy muck, too deep to walk through. It will probably be a cold winter day before I get back into some of my favorite spots. Physically, the stream is just really tough. This is typical in summer, but the water levels in the meadows make it worse than usual these days.

I caught one fish on a scud. As you know, Letort is notorious for shutting down on sunny days and I saw few fish (did spook a large one) but some were visible in typical spots and likely catchable if one could get into position to cast.

 

[wbranch]

Looks like very tough fishing for little reward.

 

[salvelinusfontinalis]

Depends on what you consider a reward.

IMO not many streams are more rewarding in either beauty, technical fishing or size of fish.

 

[troutbert]

Has there been some change that has raised the water level in the meadows?

Maybe some structural change at the I81 bridge, or below or above it, that raised the water level?

Any kind of structure that would act as a "grade control" structure could cause that.

 

[Dave_W]

troutbert wrote:
Has there been some change that has raised the water level in the meadows?

The consensus view is that increased submerged vegetation in the stream bed has contributed to this by displacing flow. I think that there is also just a lot more water due to spring seeps and flows this year as well. Areas that used to just be muddy or damp are now much wetter and often under water or so soft that walking becomes difficult or impossible.

 

[afishinado]

Dave_W wrote:

troutbert wrote:
Has there been some change that has raised the water level in the meadows?

The consensus view is that increased submerged vegetation in the stream bed has contributed to this by displacing flow. I think that there is also just a lot more water due to spring seeps and flows this year as well. Areas that used to just be muddy or damp are now much wetter and often under water or so soft that walking becomes difficult or impossible.

2018 - 2019 has had record precipitation. The water table is at a high point right now in many areas.

As an example Big Spring was flowing below normal for several years prior and now is well above normal in 2019.

 

[troutbert]

Higher baseflow this year is no doubt part of it.

But I think there is more of a long term change as well.

In the 1990s I noticed that the water levels looked higher in those meadows than it was in the 1970s.

I asked a local Letort regular about this and he and others had noticed the same thing.

His theory was that structures that were built below the I81 bridge for improving spawning habitat were backing the up the water level up under the I81 and up into the meadows.

I don't know if that's true or not. I've followed the Letort up under the I81 bridge, but I don't remember if the water seemed backed up there or not. I kind of thought there were at least some gentle riffles there.

The Letort is a very low gradient stream so it would not take much of a change to raise the water level. Some rocks placed in the stream under the I81 bridge for stabilization or habitat could do that, for example.

Or a sewer pipe crossing that raises the streambed a little.

Or a log placed for a drop structure for stream improvement.

 

[DGC]

The Breeches has leveled off at a much stronger base flow as well. Not sure if weed growth in the lower section accounts for that but I doubt it. It would indeed seem mainly a precipitation effect.

As an FYI Letort was electroshocked on 8/27 by PFBC. Unofficially the wild trout were doing quite well.

 

[CLSports]

When the aquatic vegetation grows in full in late summer then it pushes the normal water surface elevation higher and also makes for deep narrow channels.