Torrential Flooding Affects Nogales Border Tourism Area



August 3, 2016

Floodwaters rush down Avenida Ruiz Cortinez, also known as northbound highway 15, which leads to the DeConcini Port of Entry

Severe flooding walloped Nogales, Mexico today, and as the water flows downhill the massive currents of water also caused flooding in the nearby streets of Nogales, Arizona. The floodwaters have also affected the border tourism district and blocked the highway that leads to the DeConcini border crossing, and as a result tourists and other visitors are advised to take precautions and be aware that heavy localized rains can lead to flooding.

After weeks of continual rains, the ground in Nogales, Mexico is saturated, as is that in most of southern Arizona. The result is that in recent weeks moderate-to-significant rainfall results in the severe flooding that has caused havoc in the city, as massive torrents of discharge make major streets impassable, turning them into dangerous brown-water rapids.

Because of the city’s hilly terrain, rainwater flows down the paved streets of the hills, where it combines with other torrential flows and, depending on the location of the city’s north-south topography, will either flow south into southern Nogales, or north toward the international border.


The runoff from normal rainfall flows into drainage tunnels beneath the border, emerging in the Nogales wash, an arroyo that takes the waters northward to the Santa Cruz River. And a sewer main, the “international outflow interceptor,” carries sewage and industrial waste from Nogales, Sonora to a treatment facility in Rio Rico.

Under these extreme flooding conditions, the Nogales, Mexico drainage system becomes overwhelmed, which means the waters flowing into the United States may be carrying more sewage and other contaminants. And some of the excessive flow stays above ground rather than draining into the subterranean culverts, which causes the international street flooding like that experienced on Morley Avenue this afternoon.

There has been discussion regarding the construction of a retention basin south of the border to mitigate the impact of the flooding, but for now this seasonal phenomenon seems to get more destructive every year.

If you are planning travel to the Nogales border area during a time when there is significant rainfall, be aware that flooding may affect your cross-border travel plans.

Raging Nogales, Mexico floodwaters charge northward in the arroyo through Nogales, Arizona