Nogales, Sonora - Flood Control

Science Center Objects

Flooding in Ambos Nogales often exceeds the capacity of the channel and adjacent land areas, endangering people and property. Goals of RDS are to diminish impacts of flooding and sedimentation on wastewater infrastructure thereby reducing the incidence of sanitary sewer overflows. We are studying the Nogales Wash to prevent future flood disasters and RDS are being installed in tributaries. We applied the KINEROS2 model (www.tucson.ars.ag.gov/kineros/) to understand the capacity of existing and potential detention features under various flood and urbanization scenarios.

Flooding in Ambos Nogales often exceeds the capacity of the channel and adjacent land areas, endangering people and property. Goals of RDS are to diminish impacts of flooding and sedimentation on wastewater infrastructure thereby reducing the incidence of sanitary sewer overflowsWe are studying the Nogales Wash to prevent future flood disasters and RDS are being installed in tributaries. We applied the KINEROS2 model (www.tucson.ars.ag.gov/kineros/) to understand the capacity of existing and potential detention features under various flood and urbanization scenarios.

map of gabions installed in sub-watersheds

Map of gabions installed in sub-watersheds

(Public domain.)

Results depict a reduction in peak flow for the 10-year, 1-hour event based on current land use in tributaries with detention features (Fig. 1). However, model results also demonstrate that larger storm events and increasing urbanization will put a strain on the features and limit their effectiveness (Norman et al. 2010). Sediment loads are predicted to be trapped at dam locations, requiring regular maintenance to maintain capacity to detain water during flood events. Maintenance includes clearing debris, sediment buildup, and dead vegetation, structural maintenance of stone rip-rap, and vegetation regeneration on adjacent hillslopes.

Graph depicting flow with and without a dam during a 10-year, one-hour storm

Figure 1. Graph depicting flow with and without a dam during a 10-year, one-hour storm

(Public domain.)