PADL members are asking how to stabilize their shoreline. PADL is looking into what type of plants are best to use.
can be added to your shoreline. The root systems trap
sediment, keeping it on the shoreline where it belongs. Vegetation also
dissipates the energy of a wave which reduces the impact of breakers. A
wave crashes, hits the vegetation, gets slowed down, but the energy still flows
forward eventually wearing itself out. Armored or rocked shorelines actually
add to erosion as they fail to dissipate the wave energy and simply reflect
it somewhere else. It is a simple property of physics – equal and
opposite reaction. This ends up channeling the energy onto a less armored “weaker” shoreline
which will end up eroding faster. This then will provide an access point
for more wave energy to enter which eventually undermines the rocked edge as
well. Rock has another problem in that it does not trap sediment very well
like roots do. Water that crashes through the boulders eventually will
reach the finer sediment on the shore which if exposed will get lifted away
and flushed into the lake. Concrete walls cause the same thing. They
too reflect wave energy and like rocked structures increase the erosional effects. This
happens as the wave energy hits the wall and then cycles downward undermining
the wall itself. Sediment is lost under and from behind the
wall as gravity pulls down soils on the land to replace those that have been
washed to the lake bed.
Best thing to remember is that vegetation holds soil, not rocks, and thus encouraging a richly intertwined root system of many different species of plants is nature’s way of holding soils in place. Of course trees do fall into streams and lakes over time, but this too is natural and serves an ecological need as well, providing habitat, etc. Nature acknowledges this by spreading more seeds upland to replace those that grew before. End of the day (on a geologic timescale) mountains wither to the sea, and erosion natural or man-made will do its best to tear down mountains or shorelines, vegetation is the buffering system though that slows this down (on the order of centuries and millennia). So best management practice (BMP) for your shoreline…let it go wild. Get rid of a lawn should you so have one in favor of shrubs and other plants that actually have decent sized root systems. Plant low growing willow trees as they tend to grow quickly, and have a great capacity to thatch together a root system. This will protect your shoreline and property as well as use up nutrients before they get into the lake. Devils Lake used to support Sitka Spruce trees 250’ tall, which grew everywhere (many still do where development has either not occurred or where they were spared), and they grew without fertilizer, so we know naturally there are nutrients available that can sustain large (enormous) native plants. Thanks again for your inquiries. Feel free to contact us anytime.
Devils Lake Water Improvement District
Visit us on the Web at www.DLWID.org
Geosynthetic turf reinforcement mats (TRM)
Tensar wave barrier: On
July 1, 1997, we installed “Tensar” fence
with three-inch diameter size posts every ten feet as a wave barrier at approximately
the mean tide level. It was secured to the post with 1” x 2” lathing
and nailed at the top and bottom.
is much more than an erosion control blanket or mat. Slopetame2 is a permanent
three-dimensional reinforcement and stabilization matrix for steep vegetated
slopes and channel banks. The integral rings, bars, grid, and fabric act to
contain upper root zone soils, allow vegetation roots to easily pass through,
and minimize movement and loss by rain or flowing water. Slopetame2 is shipped
in roll form, with connections allowing rolls to be fastened together forming
one large continuous mat covering the entire face of long slopes. Rolls can
also be pre-vegetated by vibrating sod into rings (or growing custom plant
mixes in mat by contract), to allow mats to be placed and anchored to slopes
with established root systems, able to withstand intense rainfall or water
flow immediately. Holes can be cut in the mat to provide for large containerized
or balled plant material.
Copyright © 2003-2011
Preservation Association of Devils Lake (PADL).
All rights reserved.
P.O. Box 36
Lincoln City, OR 97367