DIR Return Create A Forum - Home
---------------------------------------------------------
Erie Canal Neighbors Association
HTML https://ecna.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: Property Owners living near the Erie Canal
*****************************************************
#Post#: 14--------------------------------------------------
How to recognize an Embankment Dam
DIR By: Doug K
Date: June 17, 2018, 10:29 am
---------------------------------------------------------
It's become difficult for many to wrap their head around the
idea a Dam is in their backyard. For those living along the Erie
Canal Trailway, mostly along the North side of the Canal where
it travels East to West, those "hills" covered with trees and
other large vegetation are hiding what is really there.. an
Earthen Embankment Dam. Looking from the bottom upward or the
ECT down the bank it's rather hard to see UNTIL you remove that
large vegetation that's slowly weakening these structures.
This is a time when a picture says it all...
[attachimg=1]
#Post#: 15--------------------------------------------------
Re: How to recognize an Embankment Dam
DIR By: Michael Caswell
Date: June 17, 2018, 6:14 pm
---------------------------------------------------------
Here are some other things to consider.
1. A dam has a spillway, to allow flood water to escape,
preventing over-topping which could cause a dam failure.
2. A dam has rip-rap, those rocks on the upstream side to reduce
erosion from wave action.
3. A dam is placed across a stream, or river, or source of
water, which coupled with the spillway, keeps the water at a
fairly constant level.
4. Earthen embankment dams are constructed in similar fashion to
the canal embankments. However, NYCC dams were constructed over
100 years ago, without the experience of modern engineering
practices.
#Post#: 19--------------------------------------------------
Re: How to recognize an Embankment Dam
DIR By: Doug K
Date: June 19, 2018, 11:27 am
---------------------------------------------------------
Great Points shared on how to recognize an Embankment Dam, Mike,
seems many sometimes try to define these Embankment Dams as
Levees which is incorrect...here's the 4 main points on how to
recognize a Levee. These descriptions are from authorities on
Levees, FEMA, USACE & Dr Donald Gray.
1) Earthen Levees are normally constructed parallel to an
existing, natural waterway, stream or river. They are placed in
a location WIDER than normal confining banks of the waterway and
built HIGHER than those banks to protect against overflow. An
earthen levee is constructed to prevent flooding of adjacent
low-lying areas during periods of high water.
2) Earthen Levee walls are normally dry most of their life, used
only as secondary protection from flooding during seasonal
related high water events like Spring thaw or when extreme
weather events occur with torrential rain that causes those
natural waterways to rise.
3) An Earthen levee is subjected mainly to tangential-hydraulic
forces (lateral scour) whereas an Embankment Dam is subjected to
dynamic hydraulic forces (wave action).
4) Earthen levees have been built mainly to withstand breaching
that can occur during over-topping conditions in extreme
flooding, through-flow and lateral scour. The presence of
vegetation on a levee helps prevent erosion that can occur
during over-topping and lateral scour. By Comparison an Earthen
Embankment Dam is designed and built to prevent over-topping and
minimize through-flow (seepage).
In summary Mr Donald Gray also has made the following comment
regarding Embankment Dams & Earthen Levees: "I don’t know of any
earth dams where woody vegetation was purposely planted or
allowed to grow on a face of the dam. Such is not the case with
earthen levees where vegetation can often be found growing on
both the landward and water sides."
Mr. Gray obviously has not been to Upstate NY and visited the
Erie Canal in quite awhile
Here's what Wikipedia says about Earthen Levees & Embankment
Dams:
HTML https://en.wikipedia.org/wiki/Embankment_dam
HTML https://en.wikipedia.org/wiki/Levee
Don't be misled here folks.. These are Embankment Dams that lead
upwards to the Erie Canal & it's Trailway. They are FULL dams
from May - November and PARTIALLY Full Dams from November to
May... still a threat to those living below them.
*****************************************************
Page 1 of 1