Marmot Dam Removal in Sandy River
What
is a Dam?
Is a barrier built
across a river and stream. it is usable
for different human purposes such as irrigation and generation of
hydroelectricity. Human have reason to build a dam and these are; generation of
hydroelectricity, irrigation, (this stop a river's natural course and water can
go in different way), control flooding (these are called detention dams, which
can stop or slow the amount of water. "There
are, three main types of dam design : embankment, gravity and arch selected
mainly according to dam–site topography and geology". (S.H.C. de Silva 1991)
History of a dam in Sandy river
The
Marmot Dam was build in 1930 and destroyed in 2007
. "The dam was built to block the main upper (easternmost) channel,
allowing all flow to enter the Columbia at the lower mouth" (Portland Hikers Field Guide website
2009). it
is one of the largest dam removed in the
Oregon history, and it took seven years to build it. The water comes from Mt.
Hood and goes to the Columbia river.
Reason
of the destruction of the Dam?
After the explosion about 23 organization took the
decision to wait for the rain season to wash the sediments, because they said
" it is a natural sediment, and doesn't contain any toxic element. It was
destroyed in 2007, and the main reason was the fishes freedom meaning that
fishes can go and back in the river, without any barrier that can stop them .
Many organization contributed with this project, however Portland General
Electric host a destruction party.
Vegetation
Type along the place where was the dam
There is a secondary succession because the soil was
already there however some people whom work for the Sandy river conservation had
add some fertilizes, and some nutrients to soil to grow plant or conifers. In
one place near to the dam the soil is a little compact , but in the other side
there is a beautiful forest where are a lot conifers trees, sword ferns, the
canopy is very open so the sun can heat the floor. The forest floor is cover by
woody debris, and the color is reddish and soft. I couldn't see any signal of
wildlife. The forest is very thick, and I identified that trees are the primary
and I saw trunks that were in the process of decomposition by fungi who are the decomposes.
What
people are doing to after the dam was removed?
There are people
have done a lot restorations projects;
Because of the type of soil after the dam was removed they had to add some
nutrients or fertilizes to soil, removed invasive plants like blackberries.
About reforestation project, by knowing
the type of soil they have been planting some conifers trees, and I saw them in
a very good growing. All of this work they were able to finish with some
organizations , a lot volunteers work from some high school, however they still
working in these projects. Some of the futures plans are to continue planting
trees, create a kiosk of information and many different things.
References
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Images
References:
What
was our the control for this experiment?
Dark
Treatment Dividing the numbers of germination by number of
seed planted, the result is the percent of germination. for example:
101/144*100= 70.14%101=Total of seed germination 144=total of seed planted.
