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Another key
element is the design and construction of the drainage system.
The Sanctuary utilizes open grass swales which have several environmental
advantages:
The trapping of nutrients & pollutants in storm water runoff.
Very mininmal fill and grading is required to provide drainage
on lots thereby reducing impacts to trees. |
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Natural drainage features, such as
this creek shown on the left, are included in the drainage design
whenever possible. |
The man made drainage outfall on the
right,
avoids trees and is constructed to function like a natural creek.
There are no banks therefore
allowing water to spill over and sheet flow
during heavy rains. |
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On the left is the same man made
creek during the winter about one
year later. New pine growth is emerging along the edges and it
now has an almost natural appearance. |
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The photo on the right shows the end
of the outfall as it nears the swamp. It flattens out to the
natural grade
to allow only sheet flow for the remaining 200' to the swamp.
However very little sediment remains to be deposited since most
of it is dropped well before reaching the
end of the outfall. |
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Irises are frequently used at main
culvert crossings to prevent scouring of the swales and also
to help catch trash and debris in the runoff. |
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