Target area is Co. Rd. 50 just north of Delano
By Ryan Gueningsman
INDEPENDENCE, MN The US Army Corps of Engineers, St. Paul District, in cooperation with Hennepin County, is seeking public comments in regard to a recently completed draft environmental assessment on a proposed stabilization project on the Crow River in Independence.
The river has experienced ongoing erosion on the channel and at the toe of the bank. The erosion has resulted in a 50-foot cliff that threatens the stability of Hennepin County Road 50, three miles north of Delano.
No significant efforts have been made to slow the erosion, according to the US Army Corps of Engineers. The erosion is currently within 10 feet of the edge of the road and poses a potential public safety hazard to travelers.
Due to high water on the Crow River during the spring of 2010, the condition of the bank has become worse.
An draft environmental assessment and section evaluation have been prepared by the district and are available for public review and comment for a period of 30 days.
This assessment includes a discussion of the need for proposed action, identification of alternatives, including the proposed action; an assessment of the environmental impacts of the proposed action and alternatives, and coordination activities.
The review period began Feb. 7 and goes through Wednesday, March 9. A copy of these documents can be obtained by contacting the district or by visiting its website at: http://www.mvp.usace.army.mil/environment/default.asp?pageid=1819.
The purpose of this environmental evaluation is to assess the impacts of various measures to provide stabilization of a failed bank that is threatening the integrity of a road adjacent to the river, according to the US Army Corps of Engineers.
Anyone may request a public hearing on this project. The request must be submitted in writing to the district engineer by Friday, Feb. 25. The request must clearly state the interest that the project would affect and how the project would affect that interest.
All requests for a hearing and comments on the document will become an official part of the project file and will be available for public examination.
What the proposal specifically will ask
The St. Paul District proposes to stabilize the existing riverbank adjacent to Hennepin County Road 50, just north of the Delano Sportsmen’s Club.
The proposed stabilization uses both riprap and bioengineered Reinforced Soil Slope (RSS) to achieve stability. This alternative would involve riprapping from the toe of the bank, 10 to 15 feet up the existing bank, followed by reconstruction of the slope above the riprap using a reinforced soil slope (RSS).
Riprap would extend approximately 20 to 30 feet out into the water. The riprap bench at the toe serves as the foundation for the RSS, which would vary in height throughout the project site, ranging from 10 to 15 feet vertically.
Above the RSS, the slope would be graded to an angle similar to the natural angle of repose and would be prepared to reestablish native vegetation following project completion.
Approximately 500 feet of the bank would be stabilized with this approach.
Access for construction activity would occur across existing Three Rivers Park District land (Lake Rebecca Park Reserve) and down the bank to gain access to the toe.
The temporary access would be revegetated with a cover crop after the project is completed, and prepared for installation of native trees and vegetation by the local sponsor.
It is estimated that construction could be completed in less than a year, though additional time may be needed given site conditions and construction logistics, such as steep slopes that result in difficult access to the site with construction equipment and materials.
Use of the Lake Rebecca Park Reserve could be inconvenienced during construction.
The main park entrance is located on Hennepin County Road 50 approximately a mile north of the construction zone.
Any road closures would eliminate park traffic arriving from south of the entrance. This inconvenience may reduce park use during periods when Hennepin County Road 50 is closed. It is unknown if, or how long the road might be closed to all traffic during construction.
Construction activities could also require closure of the canoe access immediately south of the project site. This area could be used for site access and staging of construction materials.
Closure of the boat ramp could extend throughout the construction period, which could extend over multiple construction seasons.
Once construction is completed, any effects from the project would cease. The proposed bank stabilization will have no permanent, long-term impacts on the recreational environment.
Hennepin County estimates that, on average, 2,725 vehicles use Hennepin County Road 50 each day.
Closure of the road would result in a 2.25-mile detour which would increase travel times for commuters and park users, and delay the response of emergency vehicles to the area.
If nothing happens
The no-action alternative, or future without-project condition, depicts existing conditions in the area, and assumes the continuation of existing trends.
This would be expected to include continued erosion of the bank, leading to eventual failure of the portion of the bank supporting the road surface. Failure of the road would require extensive reconstruction of the bank or relocation of the road.
Reconstruction of the bank and highway would almost certainly be more expensive than the proposed alternative, according to the US Army Corps of Engineers.
Road relocation would have impacts on private property owners as a result of right-of-way acquisition requirements, and possibly the need to relocate structures.
Road relocation also would impact the Lake Rebecca Park Reserve, which could result in undesirable social and biological impacts.
For more information
For more information, contact Elliott Stefanik, the Corps’ environmental specialist for the project, at (651) 290-5260 or email@example.com.