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US 97A - North of Wenatchee - Slope Stabilization - Complete March 2011

March 3, 2011
Click to enlarge View entire map  Three slopes above US 97A, from Milepost 203.97 to Milepost 205, north of Wenatchee, were stabilized.

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  More than 80 people attended two open houses held in February, 2008

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  Engineer Jennifer Saugen answers a question about the closure options.

Click to enlarge View entire photo  Before-South view of one slope.

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Before-North view of another slope.


Project Complete March 2011

Work on this project resumed Feb. 22 and was complete Mar. 3, 2011
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This Preservation Program project stabilized three rock slopes in a one mile section above US 97A, four miles north of Wenatchee between Rocky Reach Dam and Swakane Canyon. 

Why is WSDOT Stabilizing These Slopes?

This project will reduce the potential for rocks to fall onto US 97A between Wenatchee and Entiat. 
Three hazardous slopes were identified for stabilization by the WSDOT Unstable Slope Management Program. The slopes were evaluated, rated and analyzed for cost vs. benefit in 2006 and were funded for stabilization in the current budget. Usually a rating of 350, a cost/benefit of 1.0 and an average daily traffic count of 5,000 is necessary for funding. The average daily traffic count below these slopes is 6,000 per day. Two slopes rated 405 with c/b's of 1.08 to 1.78. The third slope was rated slightly lower (333) with a cost/benefit of .80, but due to its proximity to the other slopes and the economies of scale to address all 3 in one project, it was included as well.

To restore the integrity of these slopes these measures were recommended:

  • Debris removal
  • Rock scaling
  • Installation of rock bolts
  • Installation of steel cable netting 

The End Result
Fewer falling rocks should reach the roadway, reducing the potential for damage to vehicles and pavement. 

Project Benefits
Reduced rock fall is the primary benefit, but it also reduces maintenance costs cleaning up fallen rocks as well as avoiding costly repairs to the roadway.

What is the project timeline?
Construction started Feb. 22, 2010 and was complete Mar. 3, 2011.

Financial Information

Financial Data for PIN 209790C
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $4,738
CWA $0
Total $4,738

Project signage will reflect the cost of construction engineering, project bid award and sales tax.

On Oct. 1, 2009, four qualified bids were opened and on Oct. 5, Contract #7819 was awarded to HI TECH Rockfall Construction, Inc. for $3,664,568.94, 28% below the engineering estimate.

How can I get more information?
Project Engineer,Bob Romine
WSDOT North Central Region Project Office
PO Box 98
Wenatchee, WA 98807
Phone: 509-667-2880, or toll-free 1-888-461-8816

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