Crenshaw Water Storage and Booster Station Supply the City of Pasadena
Subsidence rules limit the amount of groundwater pumping available for drinking water within Harris County. To comply with these requirements and meet the growing demand for water, the City of Pasadena (COP) contracted with the City of Houston (COH) to purchase treated surface water. However, the existing COP metering station at the Southeast Water Purification Plant (SEWPP) did not allow COP to take the full contracted amount of 40 MGD. Improvements to the COP’s system were needed. These improvements consisted of a new metering station, ground storage with a booster pumping station, and transmission water main.
The new metering station at the SEWPP consisted of branch 30” connections from 84” high service headers, two 30” magnetic flow meters, and 1,000 LF of 36” transmission line. The metering station fed a 5.0 MG ground storage tank with four 6,000 gpm booster pumps (Phase 1). The Crenshaw Storage and Booster Station were located approximately 1/4 mile north of the SEWPP. HR Green completed all aspects of design with in-house civil, mechanical, electrical, and instrumentation and controls engineers and oversaw coordination with the Geotech sub to mitigate the risk of differential settlement at the location of the tank. An additional 2,300 LF of 36” transmission line was installed to connect the two facilities to the COP distribution system. The waterline included directional boring across two 4-lane divided roadways and a flood control channel.
After the construction of Phase 1, an increased water demand caused the City to start the design and construction of a second 5.0 MG ground storage tank at the Crenshaw site. The design included strict provisions to minimize the potential for settlement of the adjacent existing in-service tank, w/ construction provisions that included settlement monitoring to assure that the design provisions were met. Phase 2 also included a 1,500 kW emergency standby generator and a 36” PRV on the existing COP metering station line to mitigate pressure fluctuations from the COH plant.
Phase II included providing a second 5.0 MG prestressed concrete tank, standby generator, sound attenuating architectural wall, and associated civil and electrical improvements. This project provides additional resiliency to the City of Pasadena, including full emergency backup power generation and doubling the City’s capacity for water storage. HR Green completed a thorough review of pump starting and stopping, and pump control programming to ensure that the generator met expectations.
As part of Phase II, construction sequencing and staging were critical due to the significant reliance the City had on this water source. HR Green carefully coordinated construction documents to allow the contractor to complete the work that minimized facility shutdowns. The project was successfully constructed and continuously maintained distribution system pressures.