Client: Gulf Coast Water Authority (GCWA)
Location: League City, TX
Role: EOR Waterline Relocation Design and Construction Management/Inspection; Construction Cost – $1.5M
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 it was crucial the conflict with TxDOT improvements were resolved.
Aurora Technical Services was selected to provide design support services on determining the best relocation alternative to mitigate risk of existing waterline. The firm was responsible for evaluation of the optimal relocation alignment that avoided interruption of ongoing highway construction, and conflicts existing and proposed utilities and the development of the design for selected alternative, which involved the design of tunnels across IH-45 and SH-96. The design involved an accelerated schedule that require 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 Technical Services 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 maximum 48-hour shut-down of existing water supply to League City in order to maintain the water supply to the existing water system as well as coordination with TxDOT contractors to avoid delays to highway construction. Through the technical knowledge and active involvement, the project was successfully completed within TxDOT timeline and below budget.