US-70 Salt Creek Emergency Repair

Arizona Department of Transportation | San Carlos, Arizona


Sometime in the Fall of 2006, Salt Creek experienced a major drainage event that crushed most of the 3-15’ diameter corrugated plate pipes intended to pass its flow under US 70. The resulting erosion of the 60’ of roadway fill nearly caused the collapse of US 70 at approximately MP 280.5 within the San Carlos Apache Nation. Upon discovery of this damage, EPS Group was contacted to perform a very accelerated hydrologic analysis, hydraulic calculations, and an investigation of alternative repairs. EPS immediately began work and completed 70% of the effort without a clearly defined scope or signed task order. The Director of the Arizona Department of Transportation declared the project an emergency one month after work began, resulting in a change in project development philosophy. EPS quickly responded to this dynamic and delivered the required work product on schedule. Project elements included survey, BIA right-of-way definition/acquisition, tribal coordination, environmental documentation and permitting, soil nail walls; inlet and outlet headwalls; slip lining the existing damaged pipes with 13’ plate pipes; upstream and downstream regrading; the delineation of contractor access roadways; innovative traffic control; erosion control plans; and associated structural calculations and details.