A September storm ripped up several concrete panels of the Nogales Wash near the Doe Street bridge, creating a risk that the underground sewage pipe would rupture and spurring local governments to scramble for a fix.
Now, after months of exchanges among the City of Nogales, the Santa Cruz County Flood Control District, and the federal agency responsible for cross-border water treaties, a plan is set to repair the wash before the next monsoon storm hits and raises the risk of millions of gallons of wastewater spilling into downtown Nogales.
The U.S. International Boundary and Water Commission (IBWC) announced Wednesday it had awarded a $674,000 contract to Sonoma, Calif.-based Abide International to make “emergency repairs” on 240 feet of the sewage pipe, with work scheduled to run from mid-April to June 1.
After the September storm, soil was dislodged from under the panels, “creating voids that could further destabilize the IOI,” the IBWC said in a press release, in reference to the International Outfall Interceptor that carries 14 million gallons of wastewater every day from Nogales, Sonora and Nogales to the treatment plant in Rio Rico.
“We are undertaking these emergency repairs to prevent the IOI from rupturing at this location,” said U.S. IBWC Commissioner Edward Drusina. “We will continue to partner with the local community to do what is possible to prevent sewage spills.”
The IBWC contract includes removing the damaged panels, placing fill materials in the voids, and encasing the IOI in concrete.
“After this work is completed, the City of Nogales will make arrangements to replace the topping concrete slabs,” the IBWC said.
To fund the panel repairs, the City of Nogales appealed to the flood control district for help on March 4 and the district board members promised to put up $180,000 to repair the damaged section near the Doe Street Bridge and $70,000 to repair another damaged portion near Mexicayotl Academy and Arizona Bol.
The city’s request came after the IBWC told the city in December the agency did not have the authority to repair the wash, which was built in the 1930s and is the responsibility of the city.
The city and the flood control district plan to enter into an intergovernmental agreement in May and hire Nogales-based AGE Contracting to replace the damaged concrete slabs, said City Engineer Juan Guerra.
The city, flood control district, and the IBWC have long sought a plan to address the variety of issues facing the aging IOI and that vision could be realized in September, the scheduled completion date for a $610,000 study funded by the IBWC to rehabilitate the entire IOI, said IBWC spokeswoman Sally Spener.
In previous IBWC-funded repairs to the IOI, the agency spent $500,000 in 2008; $1.4 million in 2010 to replace a section of the pipe at the international border; $700,000 in 2013 to encase an exposed portion of the pipe near the Department of Motor Vehicles Building, with the City of Nogales contributing $50,000.