With the recent closure of the Five-Mile Bridge, San Juan County officials held a meeting Thursday at the Sullivan Road Fire Station to get community input on the most recent study done by international engineering firm AECOM.

A large, vocal crowd of local residents interrupted the presentation multiple times to express extreme discontent with how the county has handled the bridge situation.

San Juan County Manager Mike Stark opened the meeting by introducing County Commissioners Gary McDaniel and GloJean Todacheene, Public Works Administrator Nick Porell, Deputy County Manager Steven Saavedra and Project Manager Porter Smith.

Stark gave some background on the bridge, alluding to social media postings that stated that “the county was doing this backwards.”

Addressing those posts, Stark said the county has made great attempts over the years to preserve Five-Mile Bridge.

He said it’s a been a tough battle because the bridge was a “very old structure and we’ve had to make changes … to accommodate weight limits … height limitations and … we’ve been losing the battle with mother nature.”

After a 2019 public meeting regarding the bridge, Stark said the county commission approached the legislature about having a new study completed to determine alternatives and project costs. Previous studies were now outdated, he said, but expensive to conduct.

In 2021, the county received $150,000 to have a new study conducted. AECOM was hired in April and have completed the study, with a recommendation to close the bridge.

Stark said they wanted to see what other options were available, so they contacted their insurance carrier and asked what would result if the county chose to ignore the recommendation to close.

Fearing a lawsuit and the threat of being “deemed negligent” if there was a collapse or other events which caused accidents, Stark said there was “no choice” but to close the bridge.

The bridge was officially closed on June 5. The purpose of Thursday’s meeting was to discuss alternatives, get community input on how much transportation is taking place and determine how to best accommodate it in the future.

AECOM representative Chris Rosol said his firm was hired to examine the bridge and the existing conditions and determine options for safe access to the canyon.

Rosol said the bridge, built in about 1928, has been in Largo Wash for over 50 years and before that was previously located on U.S. Highway 64. He said the county has done a great job in keeping it up, but it has been “used and abused.”

Channel conditions have contributed to the bridge’s degradation. Rosol said the natural channel is close to 1,000 feet wide, but when they built the bridge they constrained it to about 250 feet, which drastically increased the speed of the water.

Narrowing the channel required bringing in tons of fill dirt to create a new road access, which added two S curves. The curves caused greater erosion, which led to sediment collection and eventual raising of the channel bottom.

Rosol said the road and channel only differ by about 6 vertical feet, increasing the risk of flooding. About 1,700 miles of topography feed the watershed leading to the channel. “All that water goes under that bridge,” Rosol said.

An aerial survey was completed to build a digital model the channel upstream and downstream of the bridge. The model is based on New Mexico regression equations that are specific to the area.

Rosol said the model is a good predictor of real-world situations. It showed a flow rate of almost 7,200 cubic feet per second at the channel bottom during a 25-year storm, which is seen fairly regularly, he said, adding that those flows are comparable to the San Juan River below Navajo Dam during a high flow.

The model also showed flow velocities of 10 to 14 feet per second at the bridge. Rosol said most soils in New Mexico can be erosive at 4 feet per second. During a 100-year storm, Rosol said the road would suffer the same erosion as the channel.

The county attempted to protect bridge abutments in 2017 by stabilizing the bank with a large concrete rock structure, but it has already washed out. Rosol said the bridge was deemed to be in poor condition by the New Mexico Department of Transportation in 2017.

A 2012 geotechnical study examined the soils around the bridge. After drilling 100 feet, bedrock had still not been reached, which Rosol said means “piles are … just floating in this sand.”

Utilizing the National Bridge Rating System, all four key components of the deck, superstructure, substructure and rails, were rated below five. Additionally, the bridge is only 12 feet from rail to rail, which substandard for any modern bridge.

Rosol summarized by saying the bridge “has basically lived out it’s service life,” and that it was “a risky proposal to use the bridge.”

Four alternatives were proposed, including replacing the bridge in the current location, building a new crossing on the west side of the channel, rerouting traffic to County Road 4990 or reroute traffic to County Road 7225 or 7007 in the Angel Peak area. Both rerouting options would remove the current bridge.

Rosol said the goal of the alternatives were to keep the travel time about the same as the prior route using the bridge, but attendees were skeptical that this could be accomplished.

Discussion continued for an additional 1 ½ hours, with attendees expressing concerns about increased travel time and inconvenience, speeding on County Road 4990, widening our rerouting efforts effecting personal property, risk of hitting deer or livestock and others.

Commissioner McDaniel invited attendees to reach out to him about concerns and said he is working on solutions to some of the issues brought up during the discussion.

This is an ongoing story and will be followed up on with additional coverage.