Hurricane Harvey was an unprecedented weather event that had significant historical impact to the entire Southeast Texas region, including Sienna Plantation. Harvey produced an excess of 38” of rainfall over five days within the Sienna Plantation Development. On August 25th, 26th, and 27th over 19” of rain fell which exceeded the internal drainage capacity. The Brazos River reached flood stage around mid afternoon on August 27th, therefore the gates at the outfall structure had to be closed and the pumps turned on. Once the gates were closed, Sienna Plantation received an additional 16” of rainfall over the next two days. This amount of rainfall is over twice the amount required for current design standards.
During this historic event, several employees of LJA were in Sienna Plantation offering assistance to the operator as well as the residents. LJA ordered and had delivered temporary pumps to be placed along the levee to help provide relief for the system.
Employees were on the ground monitoring the pump stations at both the North and South station, inspecting the levee to ensure no failures as the Brazos River continued to rise and collected data hourly on this record breaking storm. The District Engineer was heavily involved in the daily OEM conference calls and provided vital information to the county to aid in the decision making process regarding voluntary and mandatory evacuations.
Contact Amanda Carriage, PE, CFM, Senior Project Manager for more information.