City of Austin Guadalupe Storm Drainage Improvements

The Guadalupe Street Storm Drain Improvements project was ranked as a top priority in City of Austin’s Local Flood Risk Reduction storm drain improvements projects. The existing storm drain system was originally constructed between 1928 and 1930 and initial studies indicated that most of the more than five miles of existing storm drain pipe does not have capacity to convey to the two year design event, resulting in frequent flooding to the area. The project area had formal records of 16 building flooding complaints, 14 yard complaints, and 13 streets complaints.

The Central Austin project is located within the Waller Creek watershed, and bounded by Avenue D, West 33rd Street, Guadalupe Street, and West 47th Street. Our team assisted in the analysis of the storm drain system and performed preliminary engineering services.

The team prepared a preliminary engineering report (PER) to develop optimized solutions to reduce flooding to the area. A detailed InfoWorks ICM 2D hydraulic model was under development to simulate existing conditions including multiple recent historical rainfall events used to validate/calibrate the models. The detailed 2D hydraulic model quickly iterates through potential solutions that may include pond improvements, storm drain upgrades, street improvements, and channelization.

The data available for the existing storm sewer infrastructure constructed in the 1920s was very limited and unorganized. The data sources often contradicted each other, and various field visits were completed to confirm assumptions. Much of the information on the ponds did not match survey data or topographic information.

The project presented an opportunity for the City of Austin to develop their policy and criteria for 2D modeling including: 2D modeling terrain development; rain-on-mesh vs. detailed catchment modeling; H&H design software transformations; and simulation of inlet capacity.

The City is using the project concepts from the PER to design and construct the recommended improvements to reduce flood risk in the project area.