Danville Senior Civil Engineer Mike Stella said the storm dumped more than three inches of water into the creek abutting the road.
"At that particular site the water in the creek rose to levels we hadn't seen in a long, long time," he said. "The soil was saturated and softened, some trees collapsed into the creek and the water started washing the soil away."
The result was that much of the bed was eroded away, leaving a very steep slope near the roadway and undermining some of the roadbed itself.
"If this weren't fixed we could have potentially lost a portion of the road," explained Stella.
Because Gov. Schwarzenegger announced a state of emergency, the work was eligible for a grant. Funds for the project were obtained from the Governor's Office of Emergency Services (OES) through FEMA. Between design and execution, the cost of the project has been estimated at around $929,000. Stella said FEMA will fund 75 percent; OES will fund 18.75 percent; and Danville will fund the remaining 6.25 percent.
Design work began in November 2006, and the town hired Jim Freethy Excavating to handle the job. Stella said the plan was to have Freethy build a retaining wall to support the roadway, then to rebuild the creek bed.
The wall is now in place and the contractor will be installing cables and "tie-back" anchors to pull the wall in toward the road, giving both additional stability.
Stella said once that is completed the contractor will lower half ton boulders down on the creek bank and put topsoil over it. After the boulders are covered, a special biodegradable blanket will be placed over the topsoil to provide erosion control. Trees and ground cover will be planted through the blanket. As they take root, the blanket will degrade and eventually the root systems will stabilize the soil of the bank.
With the bank work done, Stella said the final step is to repair minor damage done to the roadway by the heavy machinery needed to do the work. If all goes well, it could be done by the end of next month.
"If the weather stays dry, maybe by next month," he said. "If the weather is really bad in the next couple of weeks we may be forced to suspend the work until winter passes."