Creek bank restoration

Lee Murray bh295 at FreeNet.Carleton.CA
Mon Jun 5 20:36:49 EST 2000


Ginseng Cooperators 

Rebuilding a creek bank 
--- countering some effects of 
Cattle Farming on neighboring Forest Preserve

--- May 2000 work started to restore the west 
bank of a small creek that has recently been damaged 
by farm practices on the neighbouring land. 

The branch called locally Cabin Creek, running from 6 to 10 feet wide and
 3 or 4 inches water depth, forms the west boundary of the woods.
The property fence is on the west bank, which is relatively level
bottom-land. The forest rises on a hill east of the creek, 15 acres 
containing 1,100 trees. 

Cattle population has increased in recent years on neighbouring
land to the west as well as the south. Cattle hooves disturb and 
loosen the soil along the fence, where cattle gather under the shade 
of the boundary trees. 

Loose soil washes away with rainfall, undermining the
tree roots and fence posts on the creek bank. About ten sections of
the creek bank, ranging from 6 to 20 feet in length, need restoration where
the top of the bank is being eroded by cattle hooves. The height of the top of the
creek bank above the water at these points is from 3 to 6 feet.

Cattle also inhibit growth of new shrubs and 
small trees along the fence line, by tramping and by eating the leaves.
This reduces the amount of roots holding the soil, so that the bottom of 
the creek bank is also undercut by the water flow.

7 large trees were removed from the west bank 
in error in 1997-98 by outside persons. Shade was thus removed 
from 45% of the length of the creek flowing through the property, 
causing changes of plant life along the creek and on the facing
forest floor of the hillside, now exposed to direct afternoon sun.
The herbs of forest and shaded water plants were quickly replaced in these
areas by fescue and other field grasses and weeds.

On a small rocky cliff face on the east side of the creek, Wild Ginger
has reduced by 80%, in this third Spring season following the removal
of shade. During summer droughts the itinerant replacement weeds die
under the hot sun, exposing the sparse soil to erosion.



The pasture field to the west slopes to drain into the creek. Here
at this point the creek bank has entirely disappeared for a distance
of 21 feet. The extreme rapid erosion resulted from a combination of 
factors. The grass and weeds introduced on the east bank pushed the
water channel towards the west bank. In the pasture field, some grading
work had been done 7 or 8 years ago, loosening the soil. Seasonal 
rains create large volumes of water rushing into the creek from the
pasture field slope. Fence posts washed out, allowing cattle 
to come over into the creek to drink water. Cattle hooves tramped out
the grass and continued to further loosen the soil in a widening area. 
All these factors created rapid and complete erosion of the creek bank.
A large amount of soil has also been eroded from the pasture field
for an area of about 50 x 100 feet.

Cattle are present upstream in the creek to the south of the property.
The increased cattle population results in large volume of manure
entering the creek. The field grasses introduced to the east side
of the creek, as well as cress and algae in the water, grow aggressively 
with this fertilized water. Minnows
and mussels have disappeared from the creek within the past 10 years.
Crawdads and frogs are present in reduced numbers.

In May 2000, a steel post was set in 600 pounds of concrete at the 
low point where the creek bank has disappeared to reinforce the 
fence against further cattle intrusion and to block the immediate
force of the water channel. Available rocks were placed under and
against the vulnerable, adjacent portion of the bank. Some of the 
encroaching fescue and mint was removed to re-open the former 
water channel and these plants were put on the rock against the 
west bank.

Plans are to bring more rock and a log, and rebuild the bank
to a minimum height of 20 inches above bedrock.

Two Cherry trees were set on the bank, one on each side of the eroded 
place where enough soil was available. These will help create roots
to hold the soil, and help make fast shade while other trees grow up.

Tree roots becoming established in 10-15 years will hold the bank
from further erosion by its own water flow. The barrier will slow
the entry of drainage water from the pasture field, allowing eroded
soil to settle and refill the washed out portion. Plans are to include
drainage pipes under and over the bank, to help facilitate drainage.


A Silver Poplar and a Walnut tree were also set on the west bank
at another location to help restore shade. Plans are to plant about
12 more trees along the bank.

Available rocks and deadfall branches were piled against some
sections of the creek bank where top and bottom erosion is 
occurring. Plans are to bring more rock and to use woven wire
to reinforce the creek bank at these several locations.

Plans to reduce manure content in the water, or counteract its
effects, are not definite. At the present time, a logjam of 
fallen trees in the creek is acting as a baffle helping to settle 
and filter the manure.


To share help or advice about restoring the creek environment,
or help with other activity to preserve this small forest
for future generations, please e-mail:  bh295 at ncf.ca

Carlos Lee Murray
Ginseng Cooperators  http://www.altnature.com/ginseng/
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--
Flute Tree                           the novel
     Fantasia in Green with Silver & Blonde
           http://www.ncf.ca/~bh295/






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