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For the Central Oklahoma Master Conservancy District (COMCD) and the City of Norman, Garver recently completed design of a new 48-inch raw water conveyance line from Lake Thunderbird to the Vernon Campbell Water Treatment Plant. Lake Thunderbird and the Norman raw water conveyance system were originally constructed in 1965. The existing conveyance infrastructure consisted of a 14-million-gallon-per-day (MGD) intake pump station and approximately 2.5 miles of 30-inch and 5.5 miles of 33-inch pipeline from Lake Thunderbird to the Norman Water Treatment Plant (WTP). The conveyance system is owned by the Bureau of Reclamation (BOR) and operated/maintained by COMCD.
Norman’s population growth has created increased water demands on the Norman WTP and the 44-year-old pipeline. The short-term WTP demand is expected to be 17 MGD. As such, the City of Norman asked Garver to evaluate the size, length, capacity, and location of a new raw water conveyance line to obtain the capacity goal of 17 MGD. Garver evaluated a variety of expansion and replacement alternatives prior to selecting the recommended plan.
Garver designed approximately 13,000 linear feet of 48-inch pipe parallel to the existing 30-inch pipe to meet the short-term water demand. As part of the design phase, extensive hydraulic modeling was completed to confirm the pipeline size and appurtenances. Additionally, geotechnical investigation, pipeline alignment, and land acquisition needs were required to identify potential construction difficulties or special design considerations. Specific features, or added value, to the project consisted of the following aspects:
- Increase waterline capacity to 19.5 MGD (15% capacity buffer)
- Existing 30-inch pipeline will remain connected and operable to existing system for emergency or maintenance operations
- Pig launching stations to allow for removal of long-term accumulation of sediment from the pipeline
- Project will serve as the initial phase of waterline expansion for a 40-year planning horizon
Due to volatile material cost and an effort to arrive at the best economical solution for the City, Fiberglass Reinforced Polyester Pipe (FRP), Reinforced Concrete Pressure Pipe (RCPP) and Polyvinyl Chloride Pipe (PVC) were all specified for construction. Bids have yet to be received, and construction is expected to commence in the summer of 2009.
Subsequent to this project COMCD is in the process of expanding their intake pump station to accommodate 17 MGD of raw water flow to the Norman WTP. |
