Another hole discovered in Sonoma County airport runway prompts emergency repairs

Construction crews are scheduled to make more emergency repairs Tuesday night on a failing section of the main runway at Charles M. Schulz-Sonoma County Airport.

The work comes less than a week after airport staff discovered a sinkhole on the north end of the main runway, where a culvert that runs underneath the airstrip is failing.

Airport officials had to shut down the main runway for 16 hours Thursday night into Friday while repairs were made, prompting Alaska Airlines, the airport’s dominant carrier to divert two of its incoming flights to other destinations.

On Monday night, another hole appeared in the runway over the culvert after an airport operations specialist conducted a “deflection test,” driving a truck over the failing pavement, said Airport Manager Jon Stout. The discovery came between 10:30 p.m. and 11 p.m. after the last commercial flight of the day, he said.

Stout said the latest sinkhole was fixed using “non-shrink, high strength grout,” but construction crews will likely do a better fix Tuesday night using concrete.

The runway was open for air traffic Tuesday and airport operations specialists have been inspecting the runway after every commercial carrier lands or takes off, said Public Infrastructure Director Johannes Hoevertsz, who oversees the airport.

Hoevertsz said the county officials, engineers and airport staff are trying to “aggressively” address the “failing culvert” and crumbling pavement.

“Tonight we’re going to look at it again and see what’s going on, and if there’s anything we need to fix we’ll fix it,” Hoevertsz said.

Tuesday night’s repairs will require the closure of Runway 14/32, the main approach for commercial traffic, between 11 p.m. and 5 a.m., Stout said. The airport’s shorter, secondary runway will remain open.

The emergency repairs at the location of the failing culvert are only a temporary fix until more permanent repairs can be made later in June. Those repairs are scheduled to start at 11 p.m. on June 24 and conclude at 7 p.m. on June 25.

In addition to the failing culvert on the runway’s northern end, pavement is also sinking and was collecting water during this winter and last winter around a concrete-encased electrical conduit that runs under a southern portion of the runway.

The deteriorating runway conditions were highlighted in a Press Democrat investigation published in April about poor pavement and other safety concerns at the airport.

The scheduled runway repairs later this month are expected to cost $667,115. That work is to come before one the busiest periods of the year for the airport — the convergence of dozens of business jets carrying guests for the exclusive all-male Bohemian Grove summer encampment.

Stout said crews are likely to try to do as many fixes tonight as possible “out of an abundance of caution.”

“I don’t want to have to continue chasing this for another 20 days,” Stout said.

You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @pressreno.

You can reach Staff Writer Emma Murphy at 707-521-5228 or emma.murphy@pressdemocrat.com. On Twitter @MurphReports.