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Re: (erielack) Flooding at Del Water Gap station
Rich,
That's a good point. Yes, the line through the Gap was built in the 1850s
in anticipation of a merger-type relationship with the CNJ to bring trains
to Jersey City via the Warren Railroad. By the time the CNJ merger fizzled
the Warren Road had already been built, which caused a misalignment to the
south that wasn't corrected until the Cut-Off was built. As such, I
remember hearing that the '55 flood was thought to be the 500 year flood
rather than the 100 year flood, since it far exceeded anything on record
along the Delaware. How they determined it was a 500 year flood is beyond
me. Anyway, it seems likely that a combination of development and more
"efficient" water drainage is taxing the capacity of the Delaware. Even
so, the '55 flood occurred with the remnants of Hurricane Diane, shortly
after the remnants of another hurricane (Brenda?) had passed through. This
most recent flood occurred with the combination of snow melt and rain,
which I believe also was involved in the 1903 flood along the Delaware,
which I think was the worst prior to the '55 flood. Anyway you look at it,
the DL&W has had to deal floods from time to time, although the 1955 flood
was by far the worst--and costly--and which played a role in causing the
DL&W to seek a merger with the Erie
Chuck
"Rich Chapin"
<rwc27q_@_nac.net>
Sent by: To: <erielack_@_lists.railfan.net>
erielack-owner_@_lists. "Tom Beckett" <tabeckett@stny.rr.com>
railfan.net cc:
Subject:
Re: (erielack) Flooding at Del Water Gap station
04/07/2005 02:20 PM
Please respond to
"Rich Chapin"
If you get into the statistics of floods, a 100 year flood is actually that
flood which has a 1% chance of occurrence. Since any 100 year period both
begins now and ends now, that 1% chance of occurrence is the same today as
it was yesterday, or tomorrow. The probability of occurrence is a constant.
I suspect the current flooding should cause a close look at the records to
see if these recent data points alter the flow vs frequency curves for this
reach of the Delaware.
The DL&W line through the Gap was built in the 1850s?? or there abouts. At
that time I don't believe anyone had the data to predict any particular
flood stage, including a 1% flood. I suspect the actual location along any
river was based on getting the highest, firmest piece of ground with the
least amount of rock blasting to achieve the desired grade. I also think
local "old timers" would have been questioned on high water levels, and the
engineer in charge of the project would have used that info in his final
decision. And, since a steam engine on a firm roadbed can move through
several feet of water, the need for a "constantly high & dry" track didn't
exist, so some degree of flooding could have been acceptable. That line was
originally built in a very different time.
RICH CHAPIN, P.E.
ELHS #3129
- ----- Original Message -----
From: "Tom Beckett" <tabeckett_@_stny.rr.com>
To: "EL List" <erielack_@_lists.railfan.net>
Sent: Thursday, April 07, 2005 12:44 PM
Subject: (erielack) Flooding at Del Water Gap station
> The other thing to keep in mind is that the "100 year flood" is a
> statistical average. You will have a flood of that magnitude, on average,
> once every 100 years. In the real world, it may occur twice in 7 months,
> then not again for 300 years. But it is true that development has
increased
> the runoff significantly versus undeveloped forest, increasing the
> likelihood and severity of any flooding resulting from large amounts of
> rainfall. For the most part, the railroads took this into account when
> locating their lines. I notice that the Erie line here in the Binghamton
> area has not been affected by any of the flooding I have seen in the last
17
> years, even though adjacent roads have been closed due to high water on a
> number of occasions, including this past weekend.
>
> Tom B
> ----- Original Message -----
> From: "Chris Lee" <leesome1226_@_yahoo.com>
> To: "EL List" <erielack_@_lists.railfan.net>
> Sent: Thursday, April 07, 2005 10:17 AM
> Subject: RE: (erielack) FW: Flooding at Del Water Gap station
>
>
> > It would not have made sense for the DL&W to spend the
> > extra money at the time to build their tracks away
> > from the river. Let's look at the stats for the flood
> > based on Easton numbers.
> >
> > Flood this past week: Crested at 36.8 ft in Easton.
> > 3rd largest flood on record
> > Flood in Sept: Crested at 33.45 ft in Easton. Was the
> > 3rd largest flood on record at the time and is now the
> > 4th.
> >
> > Dr. David Brandes here at Lafayette College figured
> > that the Sept storm to be the 100 year flood, aka, a
> > storm that comes every 100 years to a region. Dr.
> > Roger Ruggles, PE, figured this past storm to be
> > either the 250 or 300 year flood. However, according
> > to his data this does not make sense. He said that
> > historically 100 year floods generally occur with 7
> > inches of rain. We only got about 4.5 inches during
> > the storm. He believes that the larger flooding with
> > less rain is due to all the development in the
> > Poconos. The runoff from these new developments is
> > going into the river and not into the ground as it
> > used to. Therefore, it takes much less water to do
> > more damage.
> >
> > The DL&W clearly had great Civil Engineers. It would
> > have been impractical to move their tracks when they
> > were only getting the 100 year flood every 100 years.
> > Today we are getting a 100 year flood and an even
> > larger one in the span of 7 months. Flooding of this
> > magnitude was a rare occurance for the DL&W back then
> > but according to Professor Ruggles is something that
> > we will see happen more often in the future.
> >
> > Chris Lee
> > BSCE 2007
> > Lafayette College
>
>
>
>
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