H.B. No. 306 mandates the Upper Guadalupe River Authority, in collaboration with the Texas Water Development Board, the Texas Department of Transportation, and the regional flood planning group, to conduct a comprehensive study on flooding risks in the upper Guadalupe River basin. The study will involve a risk assessment to quantify the dangers posed by flooding, evaluate potential mitigation solutions, and propose up to eight projects aimed at reducing these risks. The authority is required to gather and analyze existing data, including information from the regional flood plan and recent weather events, and to develop hydraulic models for local waterways.

Additionally, the bill outlines specific steps for assessing flood mitigation solutions, including identifying various projects, developing hydraulic models for each, and engaging the community for feedback. The authority must evaluate the costs and benefits of each proposed project, rank them based on community input, and prepare design documents for the top-ranked projects. A report summarizing the findings and proposed projects must be submitted to the board and the legislature by January 1, 2027. The act is set to expire on January 1, 2028, and will take effect 91 days after the legislative session concludes.