This Emergency Relief project repairs damage that was inflicted at 150 locations on over thirty miles of US 97 (MP 150 to 182) by the storm and resultant flooding that occurred in January, 2009.
On Monday and Tuesday, Jan. 5 and 6, a combination of unseasonably warm temperatures, high winds and rain on snow covered slopes resulted in unusually rapid runoff and flooding in the Cascades. The flooding damaged US 97, Blewett Pass, including mudslides that completely blocked the highway. Flood waters undermined and collapsed the pavement in many places and caused severe scouring of embankments and headwalls around stream passage culverts. The pass was closed to traffic on January 6. The worst of the immediately visible damage was immediately addressed under an emergency repair contract. The critical repairs necessary to reopen the highway to traffic were completed on Jan. 16.
WSDOT engineers were then able to do a thorough assessment of permanent repairs needed to restore the highway to what it was before the flood. The bulk of that work was repair of the stream scour damage, wash-outs of roadway embankments and damage to large stream-passage culverts. Much of the repair work involved placement of large rock (riprap) on stream banks and culvert headwalls to prevent future high water in the Swauk, Tronsen and Peshastin Creeks from washing away the exposed highway embankment.
Construction on Stage 2 began April 27 and was complete June 30. Read the news release.
Construction on Stage 3 began August 17 and was complete by October 1. Read the news release.
The Blewett Pass Highway was restored to its pre-flood condition. While the work could not introduce any new safety features to US 97, it restored the integrity of the roadway embankments, major culverts, guardrails, roadside slopes, signage, striping and rumble strips.
| Protects Environment
During construction the roadside environment was protected by use of best management practices to prevent erosion and sediment transport to surface waters. Disturbed ground was seeded and fertilized to re-vegetate. US 97 is once again capable of withstanding the storms and seasonal fluctuations in stream flows which are typical in the Cascades.
Partnerships & Cooperation
This project met requirements of the National Environmental Compliance Act. It received a Hydraulic Project Approval from the Washington State Department of Fish and Wildlife. In addition, water quality was monitored and protected under the conditions of the Implementing Agreement with the Department of Ecology.
Stage 2 was advertised for private contractor bids on March 24, 2009. Four qualified bids were opened on April 7th and contract #7729 was awarded to Pipkin Construction Co., Inc. for $1,109,407.19.
Stage 3 was advertised for private contractor bids in June and three qualified contracts were opened July 9th and on July 13, contract #7789 was awarded to Pipkin Construction Co. Inc. for $586,473.00, (4% over the engineering estimate).
The project is funded from the WSDOT Maintenance budget with reimbursement from federal emergency relief funds through the Federal Highway Administration (FHWA).
Mike Andreini: Project Engineer
WSDOT North Central Region
P.O. Box 98
Wenatchee, WA 98807
Phone: (509) 667-2860 or toll free (888) 461-8816
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