EL CENTRO – A previous county proposal to install a precast concrete bridge on Dogwood Road over the central main canal was scrapped in favor of a precast steel truss bridge.
The planned steel truss bridge is expected to expedite the overall design and construction of the project by eliminating the need to build the previously planned concrete bridge pylons that would disrupt the channel bed and require other environmental permits.
The proposed steel truss bridge will also be notable in another regard, county public works director John Gay told the supervisory board at its meeting on Tuesday, Jan.4.
âThis will be the first in our county,â Gay said.
Plans to replace the existing concrete bridge on Dogwood Road date back to 2016, when the Supervisory Board initially approved an agreement of approximately $ 472,000 with engineering and consulting firm NV5 Inc. to provide services. design and engineering for the bridge project.
At Tuesday’s board meeting, he voted unanimously to change his agreement with NV5 Inc. to spend an additional $ 148,350 for design engineering services related to the new steel truss bridge. offers.
The ground surrounding the existing concrete Dogwood Road bridge over the central main canal is sagging at an average annual rate of about one inch. The original two feet of headroom the bridge maintained above the canal’s water level is reduced to zero during high flows, according to the resolution’s backup documents.
âIn fact, currently the water in the canal is blocked by the bridge deck,â the safeguard documents said.
Indeed, supervisor Ray Castillo pointed out during the meeting that whenever he traveled down Dogwood Road to and from Calexico he couldn’t help but notice the encroachment of the canal water and the importance of fixing the problem.
âAnother year or two, the waters will cross the causeway,â Castillo said.
The money for the proposed steel bridge will not come from the general county budget, but from the Local Transportation Authority fund.
The precast steel structure will bridge the canal in a single span, as opposed to the two-span design that the precast concrete bridge envisioned for the project. A span refers to the distance between the intermediate supports of a structure.
The single-span steel structure will also make it easier to elevate in 20 years, as the surrounding soil is expected to continue to sink, according to the resolution’s backup documents.
The area surrounding the Dogwood Road Bridge over the Central Main Canal is also occupied by a network of infrastructure, including power transmission and distribution lines, water transmission and distribution infrastructure, a line transmission line, a fiber optic transmission line, industrial facilities and a road. intersections, to name a few.
As such, the county is working with the Imperial Irrigation District, AT&T, Southern California Gas Co. to meet each entity’s standards for required improvements.
âThis area is extremely complex,â Public Works Director Gay told the board.
As part of the county’s comprehensive bridges program, Gay said county staff are focusing on the possibility of installing additional steel structures for future projects, as well as working with the IID to help speed up the process. delivery.
The only public commentator praises the supervisors
Unlike public comment sessions at previous meetings, only one community member spoke at the January 4 meeting on COVID-related mandates.
Local Sky Hall resident Ainsworth thanked the board for their willingness to provide a safe space for community members to express their diverse opinions on the various mandates related to the pandemic, and for “standing up” against those who have made threatening remarks at previous meetings.
âThank you for providing cool and calm leadership,â said Ainsworth.