Water level on the upper Chessy
- Thread starter Witzend
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In the 'middle' of the upper bay .... not as bad as Isabel, so far. Many boats are straining on their docklines but not a real problem so far.
The real question is going to be potential severe changes to the bottom depths and profiles, as had happened with Hurricane Agnes in 72 .... essentially 'doubled' the Susquehanna Flats and closed up many of the natural channels in the HdG and North East area.
There is a worrisome mega-major amount of silt backed-up behind the Conowingo Dam and the real question is: will it stay or move down into the bay. Suggest you all clean up your depth sounder transducers .... as if this becomes 'another Agnes' you're certainly going to need a real good depth sounder until the upper bay is 're-surveyed & re-charted'.
Real time Tide data from Tolchester --- http://tidesandcurrents.noaa.gov/data_menu.shtml?stn=8573364 Tolchester Beach, MD&type=Tide Data
The flood is now @ 32 Ft. above datum at the Conowingo Dam on the Susquehanna, with ALL flood gates open. H. Agnes was 36 ft. 'all time record' flood.
http://water.weather.gov/ahps2/hydrograph.php?wfo=phi&gage=cnwm2&view=1,1,1,1,1,1,1,1"
Stay safe, all.
The real question is going to be potential severe changes to the bottom depths and profiles, as had happened with Hurricane Agnes in 72 .... essentially 'doubled' the Susquehanna Flats and closed up many of the natural channels in the HdG and North East area.
There is a worrisome mega-major amount of silt backed-up behind the Conowingo Dam and the real question is: will it stay or move down into the bay. Suggest you all clean up your depth sounder transducers .... as if this becomes 'another Agnes' you're certainly going to need a real good depth sounder until the upper bay is 're-surveyed & re-charted'.
Real time Tide data from Tolchester --- http://tidesandcurrents.noaa.gov/data_menu.shtml?stn=8573364 Tolchester Beach, MD&type=Tide Data
The flood is now @ 32 Ft. above datum at the Conowingo Dam on the Susquehanna, with ALL flood gates open. H. Agnes was 36 ft. 'all time record' flood.
http://water.weather.gov/ahps2/hydrograph.php?wfo=phi&gage=cnwm2&view=1,1,1,1,1,1,1,1"
Stay safe, all.
I plan to go down again this PM and have another look. Yesterday the river was over the seawall piling tops for a while but dropped down a few inches with the tide. A fair guess as to the level then was four or five feet above normal high tide. The current in the river was probably two to three knots. Many large sticks and logs coming down.
Here is some interesting information posted to our MTOA group this morning...
Due to the flooding in the Susquehanna river basin, the river flow has increased from around 10000 cvs to over 200000 cvs on sept 8. This is changing surface currents throughout the bay significantly. Above Baltimore where the bay channel is narrow, NOAA predictions call for a complete stoppage of the Tidal flood current. Ebb currents will reach 2 knots at normal ebb. This will continue for several days.
The effects will be felt at least to the mouth of the Potomac. With all the fresh water in the upper bay, the thermohaline circulation will begin to intensify where the salt water from the ocean will drive a strong bottom current and the fresh water layer will thin and intensify. Normally, currents driven by these processes are not noticeable to navigation but these extreme events will drive unusual phenomena whose effects will be noticeable throughout the next few months.
Fisheries will be significantly affected. I cannot predict results but species who expect normal salinities and long term circulation patterns will see changes. Imagine species used to higher salinities as is typical in fall are suddenly in completely fresh water for weeks. The same for crab and fish larve who are suddenly in full seawater, and are transported further up the bay in fall when they normally would remain in the lower bay.
Tropical Storm Agnes in 1972, is the historical precedent for this event. Today our observing systems and models are infinitely better. It will be instructional to monitor the effects over the next weeks and the effect on crab and fish harvests over next seasons.
Take a look at
http://waterdata.usgs.gov/pa/nwis/uv/?site_no=01531500&PARAmeter_cd=00065,00060,00010
http://tidesandcurrents.noaa.gov
Gregory Han
Due to the flooding in the Susquehanna river basin, the river flow has increased from around 10000 cvs to over 200000 cvs on sept 8. This is changing surface currents throughout the bay significantly. Above Baltimore where the bay channel is narrow, NOAA predictions call for a complete stoppage of the Tidal flood current. Ebb currents will reach 2 knots at normal ebb. This will continue for several days.
The effects will be felt at least to the mouth of the Potomac. With all the fresh water in the upper bay, the thermohaline circulation will begin to intensify where the salt water from the ocean will drive a strong bottom current and the fresh water layer will thin and intensify. Normally, currents driven by these processes are not noticeable to navigation but these extreme events will drive unusual phenomena whose effects will be noticeable throughout the next few months.
Fisheries will be significantly affected. I cannot predict results but species who expect normal salinities and long term circulation patterns will see changes. Imagine species used to higher salinities as is typical in fall are suddenly in completely fresh water for weeks. The same for crab and fish larve who are suddenly in full seawater, and are transported further up the bay in fall when they normally would remain in the lower bay.
Tropical Storm Agnes in 1972, is the historical precedent for this event. Today our observing systems and models are infinitely better. It will be instructional to monitor the effects over the next weeks and the effect on crab and fish harvests over next seasons.
Take a look at
http://waterdata.usgs.gov/pa/nwis/uv/?site_no=01531500&PARAmeter_cd=00065,00060,00010
http://tidesandcurrents.noaa.gov
Gregory Han
RE: Water Level
Just walked in from the dock on the North East River. Water level is just a bit higher than a normal "high" high tide. Doesn't appear to be affected by the Susquehanna run-off at this point.
Just walked in from the dock on the North East River. Water level is just a bit higher than a normal "high" high tide. Doesn't appear to be affected by the Susquehanna run-off at this point.
Re: Water Level
Just got home from Perryville. The water is down about 8 inches from the high mark. About knee deep on the side walk and above the seawall. The boats are all doing fine. I will post some pictures when I have them ready.
Just got home from Perryville. The water is down about 8 inches from the high mark. About knee deep on the side walk and above the seawall. The boats are all doing fine. I will post some pictures when I have them ready.
Drove over the Susquehanna on 95 tonight on my way to the boat, even though it was getting dark could see that it was much wider and definitely rough. There were clouds that ran along the southern bank only, and they were below the level of the 95 bridge, truly an amazing site. Saw in the HdG patch site today pictures of a small sailboat drifting past HdG, hopefully it was recovered.
Down in Middle River all seems well, high tide came and went, water was high but very still, but didn't get over finger piers at our marina.
M
Down in Middle River all seems well, high tide came and went, water was high but very still, but didn't get over finger piers at our marina.
M
Muddy Waters
This afternoon we sailed to the mouth of the Sassafras. A demarcation line in the Bay paralleled an imaginary line from Grove Point to Howell Point (roughly parallel to the shipping channel and maybe 1/4 to 1/2 mile west of the channel). West of this line the water was completely brown due incredible amounts of silt. (I was content to view it from afar.)
In the Sassafras River the water appeared clean enough, but boats passing through were leaving brown wakes as the silt was brought up from below the surface. Even under sail at 4 to 5 knots we did the same.
I heard much chatter on Channel 16 about debris fields as far south as Annapolis.
This afternoon we sailed to the mouth of the Sassafras. A demarcation line in the Bay paralleled an imaginary line from Grove Point to Howell Point (roughly parallel to the shipping channel and maybe 1/4 to 1/2 mile west of the channel). West of this line the water was completely brown due incredible amounts of silt. (I was content to view it from afar.)
In the Sassafras River the water appeared clean enough, but boats passing through were leaving brown wakes as the silt was brought up from below the surface. Even under sail at 4 to 5 knots we did the same.
I heard much chatter on Channel 16 about debris fields as far south as Annapolis.
Lots of debris
Frog mortar creek has a strange color to it currently, almost like Coke syrup. Water level slightly higher than normal. Middle River looked pretty normal today but once past the entrance there was a lot of debris, lots of tree branches and other vegetation. I used to sail on the Delaware River so I am used to dodging debris. Hardly any power boats out today but lots of sailboats, winds weren't bad either.
M
Frog mortar creek has a strange color to it currently, almost like Coke syrup. Water level slightly higher than normal. Middle River looked pretty normal today but once past the entrance there was a lot of debris, lots of tree branches and other vegetation. I used to sail on the Delaware River so I am used to dodging debris. Hardly any power boats out today but lots of sailboats, winds weren't bad either.
M
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