A number of issues come together with the announcement of the
availability of issuance of an Environmental Assessment/Initial Study
and the date of a Public Hearing on the Ferguson Slide Restoration
Project. The documents will be available at the Mariposa County
Library from Monday, November 19, 2007 to January 3, 2008 with the
Public Hearing from 5:30 PM to 8:00 PM at the Board Chambers of the
Mariposa County Board of Supervisors on November 28, 2007. Copies of
the documents will also be available at the El Portal Post Office and
from CalTrans at the District Office, 1976 E. Charter Way, Stockton,
CA 95201.
This begins the process of correcting the effects of the devastating
Ferguson Slide that occurred April 29, 2006, closing Hwy 140 into
Yosemite for four and one half months. Detour bridges reopened the
highway with restrictions which included one way traffic and vehicles
no more than 28ft in length.
The economic impact of this slide on Mariposa County residents and
businesses has been significant and variable. While the average
visitor and resident has been able to use Hwy 140 with only short
delays, it has been the lack of access by the larger vehicles,
emergency vehicles, school busses, motor homes, and larger trucks
that has caused a great deal of costs. The significant increase in
costs to deliver goods and supplies to Yosemite Valley, plus the
increased fuel costs, has added to the cost of visiting Yosemite.
This will be made more difficult by the winter weather. We (the
Lodging Industry) have been working diligently to increase visitation
to Yosemite to assist the economic problems that Mariposa County has.
It is the increase in TOT (Bed Tax) that offers the greatest
opportunity for the county to meet its obligations.
Three alternative projects will be offered in the documents, both requiring
bridges to cross the river above and below the slide, one using a
tunnel, another a cut in the mountain, and a third using a viaduct
which access a notch in the shoulder of the hill opposite the slide.
Congressman Radanovich has announced that funds for the
reconstruction will be available from the Federal Government.
A few weeks ago, and unreported in the local press, an important
study by the U.S. Geological Survey was delivered to the Board of
Supervisors by Ken Gosting, Executive Director of TIE, the public
interest organization with close ties to transportation of all
aspects in California. The study crafted by Federal Geologist Roger
P. Denlinger, covers the potential effects of the slide moving into
the Merced River canyon at some future date. Denlinger does not
predict if and when that will happen, or to what degree, although he
has been studying this body of rock extensively and finds that in all
likelihood it will move. As stated in the report, the purpose of the
study was to assess the hazard posed by the Ferguson rockslide by
simulating the run out and deposition of a portions of the slide if
rapid failure occurs. As stated, the report does not address the
likelihood of rapid failure.
The rockslide is described as having a number of large tension
cracks transecting the body from toe to head wall. This means that
the slide could move in sections at different rates with the toe
moving faster than the middle portion or the near the headwall. The
study then states its purpose to delineate the hazards created by the
potential rapid release of all or part of the mass. A major
contributing factor in the possible slippage will be the content of
water from rain or snow. The angle of the slope is an important
factor. If there is a maximum deposition of talus and it fans out,
the depth of debris would be 22 meters or 67.1 ft., somewhat less
than the depth that had been speculated by earlier estimations. In a
less than full slide the toe of the slide would be estimated to cover
about 2/3 of the river with no full blockage. In other words the fan
would not cross the river. In any case, significant enough material
would continue to cause the inability to restore the original road
bed, necessitating crossing the river with the repair. The maximum
depth of debris would be about 100 ft if all of the material
available were to come down at once. It appears that a smaller slide
would reduce the opportunity for a catastrophic event none the less
would continue to occur in stages for a longer period of time.
If one were prepared to remove 780,000 cubic meters of material and
store it at a nearby location, then restoration of the present
roadway might be possible but it seems that it is no longer a
consideration because of a number of factors which include safety,
possibility of future events and the cost of removing the material
and transporting it to some location away from the river.
Environmental considerations enter into this non-option.
The hearing on November 28, 2007 will result in the adoption of a
Negative Declaration/Finding of No Significant Impact and the Initial
Study/Environmental Assessment leading to the constructing of one of
four alternative projects or possibly a no project option (Right).
The three alternatives given at the beginning of this article are the
ones being considered. It can not come too soon. We have worked
hard to keep the primary economic asset of Mariposa County viable.
There are other challenges for the future based on taking too long to
complete the project, but at least the road should not be one of them.
Leroy Radanovich
Leroy Radanovich Email:
Leroy Radanovich
To Read More By Leroy Radanovich:
Leroy Radanovich's Mariposa Life Archives
To learn much more about Mariposa County along with
historical photos:
A signed copy of "Images of America" - Mariposa County,
By Leroy Radanovich can be purchased at his web site:
Radanovich Galleria & Books
This is a early day photo of the Mariposa Mine in
Mariposa County
that is mentioned in the article to
the left by Mr. Radanovich.
This photo and others can be purchased in various sizes.
All prints are archivally printed on fiber based paper, given a selenium wash which renders the photographs permanent with a
warm tone ready for framing
Radanovich Galleria & Books
Mariposa in 1920
This photo and others can be purchased in various sizes.
All prints are archivally printed on fiber based paper, given a selenium wash which renders the photographs permanent with a
warm tone ready for framing
Radanovich Galleria & Books
Mariposa County Courthouse written by Leroy Radanovich and
Scott Pinkerton is a book about the oldest courthouse in California that is still in use today.
The book is signed by Leroy Radanovich.
To purchase the book:
Radanovich Galleria & Books
Mariposa in 1860
This photo and others can be purchased in various sizes.
All prints are archivally printed on fiber based paper, given a selenium wash which renders the photographs permanent with a
warm tone ready for framing
Radanovich Galleria & Books