FISH CAMP — With two out of three roads into Yosemite National Park out of commission, including the popular south gate entrance north of Fish Camp, the question on the minds of many is likely to be, “so when will Highway 41 reopen?”

Photos by Virginia Lazar – click to enlarge

The California Department of Transportation confirmed today that Highway 41 into Yosemite will most likely remain closed through Mar. 10. Even then, drivers may expect one-way traffic control in the area.

Crews from Agee Construction are hard at work reconstructing that portion of Highway 41, which is located about one-half mile south of the snow play area, following a series of storms that washed out the road about three weeks ago.

The washout and subsequent road collapse was first investigated on Feb. 9, then watched carefully by Caltrans as the situation continued to degrade, with the road battered by storms that hit one after another. The highway in that area has been closed to through traffic since Tuesday, Feb. 21, when the collapse became imminent and the road visibly buckled.

Currently, Highway 120 (Big Oak Flat Road) into Yosemite National Park is also closed due to weather-related erosion, making Highway 140 the only access via roadway into the Park.

Meanwhile, on Highway 41 south of Yosemite, Caltrans spokesman Cory Burkarth explains that three heavy-duty water pumps are working nonstop to safely move water through the construction zone, at a depth of about 35 feet below the roadway.

Approximately 150 feet of pipe carry the water across the otherwise empty expanse. Crews have excavated to that depth, built a dam, and will go about 15 feet deeper as construction proceeds.

The pumps will be active until they are no longer needed.

“We’re battling water right now,” says Burkarth. “Moving water through the area is what caused the erosion in the first place, and caused the road to washout. Now, we’re working on getting water through our construction site so that it doesn’t continue to erode materials beneath the roadway. Once we get the water situation under control, we’re going to be replacing the culvert beneath the roadway.”

The amount of water coming through the creek has diminished considerably since the heaviest rains; it’s a steady stream now but was running nearly 40 feet higher immediately following the stormy weather.

Back in the 1920s when the road was first installed, Burkarth says a 36-inch culvert was used to transport water under the road. For about 90 years, the engineering held up well. That is, until recently.

Heavy storms over the last two months brought unexpected amounts of rain, ice, and snow, as well as additional runoff from the snow melt. Burkarth says their contractors estimate that the water comes down the mountain at about eight to nine thousand gallons per minute.

The plan is to replace the 36-inch culvert with a new 72-inch culvert.

“We are going to double the size of it and we feel very confident that we’ll be able to safely move the water beneath the roadway with no future problems. Once we get that new culvert in, we’ll be able to fill in the gap, and rebuild the roadway from the bottom up.”

About 85 feet of highway has been compromised and removed as a result of the collapse. Design engineers will assist crews as they rebuild the slopes on both sides of the roadway. Next, contractors will need to reinstall the guardrail and posts in both directions.

“Once we get that done, we’ll be able to repave the roadway and get it open to traffic as soon as we can,” Burkarth adds.

Timing is dependent on weather, and while warmer days are better for working, they also create more runoff from melting snow.

Caltrans is hoping to reopen Highway 41 into Yosemite by Mar. 10, even if that means one-way traffic control will be in place. We will update again when more information becomes available.