IH-45 39” Water Line Relocation

TxDOT improvement on IH-45 South in the League City region created a conflict with an existing 39” concrete transmission waterline owned by GCWA. The transmission waterline is one of the main sources of potable water for the City of League City, therefore the conflict with TxDOT improvements was resolved.

Aurora was selected to provide design support services in determining the best relocation alternative to mitigate the risk of the existing waterline. The firm was responsible for the evaluation of the optimal relocation alignment that avoided interruption of ongoing highway construction, conflicts with existing and proposed utilities, and the development of the design for selected alternatives, which involved the design of tunnels across IH-45 and SH-96. The design involved an accelerated schedule that required construction to be completed within TxDOT’s timeline for the highway improvements. The project also involved multiple easement acquisitions and negotiations with property owners affected by the relocation.

Aurora was also selected to provide construction-phase services and construction management and inspection services for the construction. Construction of the relocated waterline segment involved the tunnel of approximately 350 LF of 36-inch steel waterline in 48” casing underneath Interstate 45. During construction, several challenges were encountered such as tunnel construction in unexpected high-groundwater flow conditions dictated the use of deep well points activated in phases to minimize the risk of settlements underneath highway bridge structure. Wet connection to the existing 39-inch concrete waterline had to be performed within a maximum 48-hour shut-down of the existing water supply to League City to maintain the water supply to the existing water system as well as coordination with TxDOT contractors to avoid delays to highway construction. Through technical knowledge and active involvement, the project was completed within the TxDOT timeline and below budget.