Conowingo Time Bomb

[sparky1423]

Interesting article I came across after scoping out possible cold weather fishing oppurtunities. It's a lengthy article, but a good read. The more I read about enviorenmental concerns and the declining shad and striper population, it feels like I should be doing more than picking up trash along our launches.

http://www.bwi.org/bwicontest/files/...medifyoudo.pdf

[DanMarino]

I don't see the link for the article.

[sparky1423]

Just added....guess that would help

[toyomo]

That was a very interesting read. I had no idea all the concerns with sediment behind the dam. I think i read here in this forum about the impact of hurricane Agnes on the Bays striper population but now i understand the why part. The NASA satellite image is crazy and very eye opening. I also was surprised to hear that the "pond" is aerated to keep the fish alive!

[Mark]

Thank you for posting.

Let's hope the Army Corps, MD, PA and NY stop the ticking.

[gliebig]

They'll just spend $$$$$$$$$$ on study after study and kick the can down the road as long as they can.

[Mark]

I'd like to think a little more positively.

Poplar Island is an example locally of the Feds and MD working well together for the environment and the Port of Baltimore.

[DOGFISH]

There was actually a salmon run in the Susquehanna. Until about the early to mid 1700s, when there was already too much run off and too much sedimentation from agriculture. This was long before dams. The same concern has been a topic in the western states, where dams are being taken out for reclamation projects.

I have written about this before. I went into the Navy in April 1972. There was plenty of seaweed, the same as from when I was a kid. When I got out three years later, all the seaweed was gone. The shorelines were barren. So, I am sure Agnes had something to do with it. It does take public outrage for anything to be done. It sometimes seems as if even that is not enough.

[Memory Maker]

There was actually a salmon run in the Susquehanna. Until about the early to mid 1700s, when there was already too much run off and too much sedimentation from agriculture. This was long before dams. The same concern has been a topic in the western states, where dams are being taken out for reclamation projects.

I have written about this before. I went into the Navy in April 1972. There was plenty of seaweed, the same as from when I was a kid. When I got out three years later, all the seaweed was gone. The shorelines were barren. So, I am sure Agnes had something to do with it. It does take public outrage for anything to be done. It sometimes seems as if even that is not enough.

Yeah Don ......... I can remember back in the 60's when the grass on the flats was so yast and thick that no motorboat could make it through .......... And the shad and herring were so thick that you could dip net them .......

[sparky1423]

I also found this information while searching for the reason why crappie are virtually non existent above the dam:

The relative abundance of white crappie in Conowingo Pond has dramatically decreased since the mid- 1970s, although fluctuations in year class strength noted historically remain common. Catches of white crappie in 2010 were nearly zero for all gears (trawl, seine, electrofishing) and it appears that the white crappie population has declined to an extremely low level in Conowingo Pond. A number of events may have affected white crappie abundance in Conowingo Pond, beginning during the 1970s and continuing to the present. These include large storm events with associated runoff in 1972 and 1975 that intermittently depressed the crappie population in the 1970s. Likely more important to white crappie abundance over the long term is the continuous presence of gizzard shad since their original introduction to Conowingo Pond in 1972. Currently, and since 1997, up to one million adult gizzard shad enter Conowingo Pond each spring via the East Fish Lift at Conowingo Dam. It appears that abundant larval gizzard shad produced each spring have been at least partially responsible for the low recruitment of white crappie from larval to adult life stages. The high fecundity of adult gizzard shad and annual replenishment from downstream likely continues to depress the white crappie population in Conowingo Pond.

[LoudounFisher]

I doubt this phenomenon is unique to this dam. The bigger the river, the bigger potential consequences are.

During the summer I made a trip down Goose Creek in Loudoun Co hoping to find some deep water in the Goose Creek Reservoir where the dam is.
I don't know how deep the reservoir was originally but I was surprised to find it was less than 6' deep near the dam. I didn't get right up the edge but it seemed to get even shallower. The deepest I saw in the reservoir was about 12'. From the top of the dam to the creek below is 40'. I would imagine the original depth of the reservoir was closer to 40'.

After looking for some actual dimensions, I found it has a surface area of 120 acres and capacity of 4373 acre feet which would suggest an average depth of 36'. It's not even close. Loads of sedimentation is why. This is why they have to draw water from Beaverdam Creek Reservoir when the creek flow is low like during my trip.