Increasing Redundancy to Prevent Water Service Disruption in Houston

After a catastrophic failure on the City of Houston’s North 60 (N60) water transmission line that disrupted service to a million customers in the Greater Houston Area in 2001, the City has taken a proactive approach to prevent further disruption. Though others have occurred while an alternative source has been identified, none have had the same impact as the failure in 2001. Over the last 10 years, an alternate source was identified to provide redundancy to the system through designing and constructing a 72-, 66-, and 60-in. waterline (Contract 70) to bring additional water from Houston’s Southeast Water Purification Plant (SEWPP) service area into the area supplied by Houston’s East Water Purification Plant (EWPP).Contract 70 included evaluating and installing approximately 44,700 linear feet of 72-, 66-, and 60-in. waterline through multiple contracts that included passing Houston’s Hobby Airport, multiple fault crossings, United States Army Corps of Engineer’s (USACE) water crossing, major thoroughfare crossings and will provide take points to multiple smaller pump stations and authorities in the area. Several unique issues had to be accounted for during the multiple segment designs that included shoring and shutdown sequencing to minimize impact when connecting to the existing 96-in. waterline along Fuqua;improvements including a new metering station and roof replacements at a key repump station required prior to full installation of Contract 70; working next to Houston’s Hobby Airport and coordinating with the FAA for determination of No Hazard to air navigation for temporary structures; and multiple large diameter tunnels totaling 3,000 LF and also included a crossing of USACE maintained Sims Bayou and tie-in to existing 60-in. PCCP waterline. With the last segment of the transmission line nearing completion, the waterline will be completed allowing further preventive maintenance needs to be addressed along two critical 60-in. waterlines, installed in the 1960s, and the entire Contract 70 waterline to be placed into service.