Transcript Coeur d’Alene Lake

Silver Valley Streambank
Stabilization
A Local Perspective
By W. C. Rust
April 20, 2011
The Problem
EPA has said ”South Fork Flooding is a large
system-wide Concern. EPA is concerned about
flood threat to the remedy, but large scale flood
protection is not our area of expertise and is
outside of our regulatory jurisdiction.
Addressing this will require many entities
including the Corps of Engineers and FEMA and
a large investment in time and dollars.
Therefore it will not be part of the ROD
Amendment.”
But EPA is Proposing to Remodel
the Stream Channels
In the Proposed Plan a large part of the
remedy is the removal of millions of cubic
yards of contaminated sediment from
impacted floodplains and bioengineered
stream channel stabilization for most of
the South Fork and It’s major tributaries.
Stream & Riparian Improvements
Biostabilization Conceptual Design
Biostabilization Conceptual Design
Biostabilization Engineering
The 2003 Biostabilization Approach
Document says vegetation is effective
for low velocity and low flow but is
rarely effective during flood conditions.
These concepts are designed to fail
during flood conditions.
Reach MG01-1 Above Ninemile
Reach MG01-1 Above Ninemile
Table 6-17 of the FFS Calls for Installing
900 Feet of Bioengineered Revetments,
26 Current Deflectors, 0.8 Acres of
Floodplain/Riparian Planting and 3
Sediment Traps in This Channel. FEMA
Says the Present Channel Will Not
Contain the 100 Year Flood. These
Modifications Will Make it Worse.
S. F. Through Kellogg
Kellogg Area
The FS Says no contaminated sediment
removals or streambank stabilization is
planned for this area because they
assumed it would be done by OU2. EPA
did not include this in OU2.
The Streambanks are constructed of
unarmored contaminated sediments.
This area should be treated like all the
other impacted floodplains to prevent the
release of contaminated sediments.
The Impacted Floodplain Remedy
The Local Communities Generally Support
Cleaning Up and Stabilizing the Impacted
Floodplain
The Cleanup Must be Supported by Rigorous
Engineering That Provides for Protection of
Adjacent Development and Infrastructure from
the 100 Year Flood
The Cleanup Must Include a Long Term
Maintenance Plan to Assure That Protection
Continues.
Conclusions
Over $200 Million of the Proposed
Remedy is for Actions in the Impacted
Floodplain of the SFCDR
A ROD selecting a remedy containing the
streambank stabilization components of
the present proposed plan will not be
acceptable to the citizens of the Silver
Valley