Flood Planning for Border Resilience

How does River Basin Flood Planning work?

Most communities have a false sense of security when it comes to flood risk. The FEMA flood insurance maps that most of us depend on may date back decades, and fail to account for urbanization that may be changing the location of the floodplain. This is certainly the case in the four southernmost counties of Texas, Hidalgo, Cameron, Willacy and Starr Counties. Even within these counties, the quality of floodplain information varies widely from place to place. Whereas some frequently flooded communities conduct their own studies to fill in the gaps, in smaller, more rural communities, flood maps may not exist at all.  This effort will focus on lessons learned from the Texas General Land Office's Lower Rio Grande Valley River Basin Flood Study (RBFS), while speaking to concurrent efforts going on in the region. When NOAA published the Atlas 14 Study in 2018, the Agency projected that an additional 1" in rainfall for 100-year storms in the southernmost portion of the Valley, principally in Cameron County near the Gulf of Mexico. Since 2015, however, this region has received a Federal Disaster Declaration for floods and/or tropical storms almost every year.

Although this increase in South Texas isn't as dramatic as it might have been for communities along the upper portions of the Texas Coast, this anticipated rainfall may lead to new development patterns and infrastructure design standards for this low-lying region of Texas' Southern Coastal Plains with little change in topography.

What Factors Make Flood Planning Difficult in a Cross-Border Setting?

Multicultural setting.
While the majority of residents in South Texas are comfortable in both English and Spanish, fluent communication around planning for future flooding requires materials to be available in both English and Spanish. Depending on whether residents have been educated in the U.S., or in a Spanish speaking environment in Mexico or Central or South America, they may be more comfortable with technical and policy terms in one language than another. Making materials available in Spanish may also aid with translation between co-workers or family members by expanding the reach of the message. To reach populations who are not likely to attend an event at City Hall, working with Spanish language media is important as well. This is particularly important when sending out emergency preparedness information and emergency alerts.

High Levels of Social Vulnerability
In this project's planning area, all four counties also have a Social Vulnerability Index ratio approaching 1, according to the Centers for Disease Control (CDC). Similar SVI scores can be seen in almost all of Texas' border counties. This indicates the highest possible level of vulnerability, and factors that may influence the score in border regions include language barriers, income per household, household size and access to a vehicle.

The householder's location in relation to the floodplain plays a role as well. Many communities along the Texas/Mexico border struggle with a difficult planning challenge. Land in floodprone areas is less expensive to acquire, and the colonia communities that can be found throughout the Texas borderlands often intersect with the floodplain. Residents of colonias, which the Texas Attorney General's office describes as "substandard housing developments, often found along the Texas-Mexico border, where residents lack basic services such as drinking water, sewage treatment, and paved roads" may be unfamiliar with the real estate market in the United States and unaware of the flood risks associated with their property. This is particularly true when these informal settlements are located in unincorporated areas where planners have little to no ability to enforce the construction standards that could make them more resilient.

Coordination Across International Lines

Because both Mexico and the U.S. share the waters of the Rio Grande, infrastructure on either side has the potential to affect flood risk. The footings of the bridges that serve as international crossings and border walls can reduce the storage capacity of the floodway. Debris from events upstream can cause obstructions in the river or in its tributaries that result in flooding of homes or fields. Releases from dams further upriver can have an effect as well. The U.S. and Mexico work together to address these and other border resources through the International Boundary and Water Commission (IBWC). The role of this organization includes: distribution between the two countries of the waters of the Rio Grande and of the Colorado River; regulation and conservation of the waters of  the Rio Grande for use by the two countries by joint construction, operation and maintenance of international storage dams and reservoirs and plants for generating hydroelectric energy; protection of lands along the river from floods by levee and floodway projects; solution of border sanitation and other border water quality problems; preservation of the Rio Grande as the international boundary; and demarcation of the land boundary. Both the Texas Water Development Board and the Texas General Land Office flood planning efforts are coordinating with the IBWC to share data and studies that may lead to improved flood management. It is anticipated that the final plan may also identify projects that may reduce vulnerability for both countries.

As a part of these flood studies, the GLO and the Halff team will work with community representatives to develop more effective floodplain data, to identify new policies and procedures and to plan for infrastructure improvements that will keep the Lower Rio Grande Valley's most floodprone communities safer in future floods.

Lessons for Working in a Binational Context

- Don't assume that speaking a common language will bridge all cultural barriers to producing an effective plan
- In advance of hurricane season, identify populations that are more socially vulnerable to flooding events because of language barriers and settlement patterns
- Build both official and personal relationships with counterparts across the border whenever possible to improve communication and collaboration
- Prepare and mitigate for unexpected events that may originate across the border.