Repair work scheduled for Chimney Rock Road

With no storms in the immediate forecast, County of San Luis Obispo Public Works is now able to begin repairs to Paso Robles’ Chimney Rock Road that was washed out during an early March atmospheric river event.

Steep terrain, unstable soils, rising lake levels, and a continuous stream of storms since March 9, have hampered repair efforts, and the break in weather means we will begin repairs on Monday, April 3.

By the week of April 24, weather and site conditions permitting, it is expected that stranded residents in the lakeside communities of Running Deer Ranch, CAL-Shasta, and Tri-Counties will have access to and from their homes for the first time since March 9.

The washout will be repaired in three phases. In the first phase, Public Works and local contractor, David Crye General Engineering Contractor, Inc, will build a temporary road upstream at a lower elevation than the existing road. Once open, the road will provide limited access to residents, construction equipment, and emergency vehicles only. Though the temporary road will be passable for vehicles, the site remains an active construction zone, and drivers are advised to exercise extra caution on the roadway.

For the second phase of repair, Public Works and Souza Construction, Inc. will construct a temporary bridge over the washout on Chimney Rock Road. This one-lane bridge is expected to be open to all vehicles this May.

Once the temporary bridge is in place, the County will move to the third and final phase, which will be the long-term repair of the road. For the long-term fix, Public Works is considering a permanent bridge or a large-diameter culvert capable of passing large debris for 100-year storm flows.

Temporary traffic control devices will be installed to support traffic through the construction zone during all phases of the project. Please see map for location.

Background – During the first major storm system to hit San Luis Obispo County on Jan. 9, culverts beneath Chimney Rock Road at milepost 12.425 (near Fawn Lane) washed out. County staff completed an emergency fix and reopened the road on Jan. 24. Debris from subsequent storms damaged one of the two culverts leading to a complete failure of the road and embankment when another major storm hit the county on March 9. The new washout created an 80-foot long and 50-foot-deep canyon bisecting the road.

This unprecedented storm damage is indicative of the fact that almost 90 inches of rain have fallen in this area of San Luis Obispo County since December 2022.