Flooding in Texas and the Gulf of Mexico region negatively impacts millions of people each year. Flooding can lead to negative impacts on the economy and increased costs to healthcare, property, and infrastructure. Hurricane Harvey demonstrated the disparity and lack of existing information on where floodwaters would pool or move, how long it would take the water to recede, how many people were obstructed by floodwaters, and what peoples’ exposure is to flood risks. Having accurate information before, during, and after a natural disaster saves lives and protects critical infrastructure and property. Maps that link the natural and built environment to the locations of people, resources, and vulnerabilities enable communities to prepare for, respond to, and recover more effectively from adverse events.

This project sought to address two pressing urban flood problems in Texas: 1) Texas’ vulnerability to chronic and repetitive urban flooding, and 2) the need for more comprehensive flood maps to convey risk. The 100-year floodplain serves as a primary communicator of flood risk for many communities even though they were never intended to convey flood risk, rather the boundaries of the floodplain were drawn to set insurance rates. The FEMA floodplain delineations and maps do not accurately reflect flood risk and they are poor predictors of flood damage, especially in urban areas. They do not and never were designed to convey information related to depth or duration of inundation, water flow, historical damage, or susceptibility to pluvial or compound flooding. However, communities make decisions based on these maps which often result in misguided efforts to increase flood adaptation and resilience.

To address these problems, Resilient America partnered with Texas A&M University at Galveston (TAMUG) in 2019 to investigate flood risk and historical flood loss in communities across coastal Texas to develop and test novel ways to communicate flood risk and impact in urban areas. Specifically, this project set out to produce novel maps and other visualizations generated by integrating multiple data sources and models that indicate flood risk and flood impact areas in coastal communities subject to repetitive floods in Southeastern Texas.

The purpose of this project was to better measure, map, and mitigate flooding, especially in areas outside of the FEMA 100-year floodplain. This project assessed the causes of repetitive flooding within specific communities and used this information, in addition to other data sources, to create maps and visualizations that better communicate flood risk.

A critical component of this project was to engage with community stakeholders who could provide input about areas that flood repetitively in their communities. While TAMUG developed the flood risk maps, Resilient America conducted community meetings in Greater Greenspoint (a super neighborhood in Houston), Harris County, and in Lake Jackson and Richwood in Brazoria County. Information collected during the community stakeholder meetings was integrated into new flood risk models to create better maps of areas at risk of flooding. In future work, the ultimate goal is for these maps to convey information about historic flood damages, annual flood loss estimates, and spatial representations of savings associated with specific flood risk mitigation actions. Community stakeholders will provide feedback on the effectiveness of these maps at representing actual flood risk as experienced in the community and potential ways to enhance the maps to more clearly convey risk information.

The overall goal of this project is to create maps and other visualizations or products that better communicate flood risk. Towards this effort, project objectives were to:

• Better understand how diverse stakeholders perceive, assess, and communicate flood risk;
• Develop maps that more accurately convey flood risks and flood impacts;
• Ground truth flood risk and flood impact maps with diverse community stakeholders; and
• Design flood visualization products that inform and motivate individuals and organizations as they take actions to mitigate their flood risk.

This project carried out three main activities: community engagement work, development of a prototype flood map for Greater Greenspoint, and an annual partners' meeting.

Example of stakeholders groups that participated in the discussions:

• local and county government (e.g., elected officials, public works, economic development, floodplain management, engineering, planning and zoning, infrastructure, stormwater management, etc.)
• state and federal government
• nonprofits and community- and faith-based organizations
• academia (e.g., researchers, scientists)
• emergency management and first responders
• natural environment and sustainability groups
• historic preservation societies
• the private sector

Some of the common challenges identified across community stakeholder groups:

• lack of flood preparedness
• barriers to flood risk communication
• impact of development on the flood risk
• impact of floods on health