Cottonwood Wash Bridge damage results in closure of 28 miles of State Route 95
by David Boyle
A commonly-traveled route in San Juan County has been closed for 60 days after Utah Department of Transportation (UDOT) officials discovered damage under a bridge.
On August 5, UDOT announced the extended closure of the Cottonwood Wash Bridge on State Route 95, approximately nine miles west of Blanding.
The closure impacts a variety of routes through the Canyon Country, including travel west of Blanding to Hanksville, Lake Powell, Natural Bridges, Bears Ears, and Cedar Mesa.
A routine general inspection of the bridge revealed potential issues with erosion – or scouring – in the sandstone abutment that holds the bridge in place.
In an interview with Red Rock 92.7 FM, UDOT Region Four Communications Director Kevin Kitchen explained UDOT does bi-annual inspections of all bridges on federal and state roadways in the state, as well as some county bridges of a certain size.
A routine inspection on August 3 alerted UDOT officials to potential serious damage under the bridge. Further evaluation of the bridge by a team of engineers determined the collapse of sandstone at the footing of the east abutment was significant enough to close the bridge for public safety while UDOT pursues an emergency repair to the structure.
Kitchen explained UDOT has a team of structural engineers working towards a temporary solution.
“The evaluation basically showed that we’ve had an undercutting of rock,” said Kitchen. “There’s a big slab of sandstone underneath the east abutment footings that collapsed. Some of the chunks from that slab that broke off into pieces were five feet in diameter. Some of the boulders that resulted from that erosion had fallen down underneath that.”
Engineers say it appears high flows in the wash during flash flooding scoured away a lower layer of rock, leaving the upper layer of rock unsupported. The bridge was built in 1959 and spans approximately 110 feet.
Kitchen said in the previous bridge report, issued in 2019, engineers found the bridge to be in good condition and the substructure to be in satisfactory condition.
“If you were to look at it today, the (recent) flash floods have had an effect,” said Kitchen. “The water level was high on the rock and the force of some of those flooding events most likely did contribute to this current situation that we’re in.”
UDOT engineers are already at work to reestablish a safe crossing over Cottonwood Wash.
The current closure of State Route 95 extends approximately 28 miles from the Junction of US-191 to State Route 261.
UDOT crews have deployed portable electronic message boards from several maintenance stations in Southern Utah to key highway junctions to help inform motorists of the closure.
There are a number of routes on dirt roads that may circumvent the closure, but they can be problematic for many vehicles with low clearance.
UDOT recommends Interstate 70 to State Route 24, through Hanksville, for paved access to Upper Lake Powell and other outdoor recreational destinations west of Blanding.
Although UDOT is not advising its use, Highway 261, up the Moki Dugway, is one route to locations in the general area. The steep, narrow dirt road up the Moki Dugway is not suitable for larger vehicles.
Travelers and locals unfamiliar with the area should discuss travel plans with visitor services who have knowledge of the area.
UDOT also warns drivers that cellular phone GPS mapping apps for motorized vehicles may not be reliable in the region for routes off of the state and national highway systems.
Public inquiries regarding the bridge repair project may be sent to firstname.lastname@example.org.