HIGHWAY 39: CALTRANS VS. MOTHER NATURE
Neither rain, nor sleet, nor snow, etc. can keep Disrict 7 from opening up this challenging route.
If there ever was a hard road, it’s District 7’s portion of Highway 39, 27 miles that runs from the Angeles Forest Information Center at the northern Azusa city limits to the junction of Angeles Crest Highway (SR-2).
Pounded by rain, snow, landslides, fires and everything else Mother Nature can throw at it, the highway has been one of District 7’s biggest challenges for decades, since the massive Snow Springs slide in 1977 destroyed the original alignment and drainage systems, said Maintenance East Region Superintendent Vern Gemeinhardt.
“That slide had just been cleared and the highway reopened when a second slide blocked the entire highway and the three drainage systems with hundreds of thousands of cubic yards of large rock and soil debris,” Gemeinhardt said. “Before that debris could be cleared, additional slides destroyed large sections of the pavement, roadbed, engineered fill slope and drainage systems.”
Subsequently, the highway was closed with locking gates above and below the slide, and remains closed to this day. “Efforts to rebuild the highway were stymied by the scale of the slide damage and the lack of available funding for engineering work,” he said. Meanwhile, additional slides and harsh winters over the years continued to compound the damage, while Maintenance fought an uphill battle (literally) to keep the site stable.
Efforts to reestablish emergency access across the slide face began in 1996. By that time, Gemeinhardt said, the original roadbed and pavement were almost completely gone and the slope had eroded an additional 100-plus feet from the designed highway alignment.
The work consisted of placing and compacting heavy rock and slough debris to create an access lane, which was removed from the roadway and drainage flow lines. Then, a nearly seven-foot earthen berm composed of compacted native material was constructed on the down-slope side of the access road. “A wide cleared area on the right side help capture and contain slide debris,” Gemeinhardt said. “The berm also serves to direct storm run-off to the remaining (functioning) drainage inlets.”
Then came the El Nino winter of 1997-98, which brought onslaughts of rock and debris onto the closed section of the highway, blocking the road and drainage flow lines to the surviving highway drainage systems. Again, work was needed to clear the material from the highway and use it to strengthen the emergency access lane support slope at the Snow Springs site.
“Heavy winter rain, deep snowfall, and extreme temperature variations increase the frequency and volume of this rock and debris fall,” Gemeinhardt said. “Maintenance crews clear this material from the pavement and shoulders on a year-round basis to maintain drainage flow-line efficiency, to allow continued emergency access through the closed section, and to protect traffic from the debris.” This material is always placed in permanent storage locations approved by the U.S. Forest Service, working together with Caltrans office of Environmental Planning, State and Federal regulatory agencies, he added.
During the dry season, from May into early November, other on-going Maintenance efforts include: removing slough from the roadway shoulders, draining inlets and flow-lines in preparation for storm run-off and to provide maximum temporary storage capacity for winter slough volumes and repairing/reinforcing roadside berms.
This might seem like a lot of work just to maintain an impassible highway, but it’s an obligation Caltrans must fulfill, said Damage Restoration Coordinator Bill Varley. “The District has a long-term commitment this highway.”
At one point, he added, Caltrans looked at abandoning the highway to the U.S. Forrest Service, but the agency would only accept it if we returned it to wilderness conditions, which would have been even more costly than re-opening it.
Following severe fires in 2002 and the storms of 2004/2005, Highway 39 was declared a state and federal disaster area, Varley said, and the road was closed at the bottom of the hill. Repair work was performed from the bottom progressing up the hill and several sections were completed under that emergency contract. However, seven sites remained that required engineered fill or retaining walls.
Two projects that will address those issues and get the highway reopened are scheduled for construction soon. The first, building two retaining walls near the city of Azusa from Old San Gabriel Canyon Road to approximately four miles south of SR-2, could begin in mid-2009. The second, a $45 million project to reconstruct the roadway, construct soldier pile retaining walls, repair drainage systems, install rock fall protection, and provide asphalt concrete overlay and traffic striping, should begin in fall 2010.
This begs the inevitable question: what happens when the next big storm/fire/slide hits? Varley said the project includes measures to control rock fall and run-off. And Caltrans will continue to maintain the road. As far as future damage is concerned, he said, “That’s the challenge of Route 39.”