Engineering Solutions for Complex Regional Water Transmission

LAN designed 1,000 LF of 84-inch steel waterline, including a 385 LF crossing beneath the Trinity River through a 108-inch tunnel in hard rock, to replace an aging 72-inch prestressed concrete steel cylinder waterline. The design incorporated vertical drop pipes within 100-foot-deep secant pile construction shafts, saving more than $11 million while improving constructability and safety. Cost-conscious steel fitting details and a galvanic cathodic protection system further supported economical construction and long-term corrosion protection.

As General Engineering Consultant to the Upper Trinity Regional Water District, LAN evaluated pumping strategies and developed the schematic design for the Lake Ralph Hall Raw Water Pump Station, with an ultimate capacity of 80 MGD. Services included pump selection, hydraulic system curve development, electrical load identification, station layout concepts, and value engineering across varying operating conditions and lake levels. LAN also guided bidding and construction planning for the pump station, raw water pipeline, and balancing reservoir, evaluating market conditions, labor availability, procurement timing, and critical-path construction activities.

LAN has served as Program Manager for the City of Houston’s Surface Water Transmission Program since 1985, supporting the planning and implementation of major water transmission infrastructure. LAN’s responsibilities include managing design consultants, negotiating scopes and fees, preparing standards and specifications, reviewing design milestones, controlling costs and schedules, and coordinating easement acquisition, environmental compliance, and permitting. The program supports reliable water service and the City’s transition from groundwater to surface water.

LAN designed the Richland Chambers Flow Control Structure as part of the Integrated Pipeline project for Tarrant Regional Water District and Dallas Water Utilities. The 235-MGD flow control and pressure-reducing facility connects a 108-inch steel pipeline to the existing 90-inch Richland Chambers pipeline. The project was the first of eight pipeline segments delivered and was bid more than 17% below budget.

LAN provided design and construction engineering services for 18,300 LF of 72-inch steel waterline connecting the Tom Taylor Regional Water Treatment Plant to the Stonehill Pump Station for the Upper Trinity Regional Water District. Designed to meet increased water demands from rapid growth, the pipeline parallels an existing 48-inch waterline and includes nine tunnel crossings. LAN’s scope included tunnel and vertical drop shaft design, specialized fittings, valve design for a 16-hour shutdown window, agency permitting, and cathodic protection with soil resistivity testing and stray current analysis. Design was completed on an accelerated 10-month schedule to support construction completion before summer 2021.

LAN designed the tunnel crossing beneath US 59/IH-69 as part of the City of Houston’s Northeast Transmission Line, a 16.5-mile water conveyance system connecting the expanded Northeast Water Purification Plant to partner communities west of the city. Constructed approximately 50 feet beneath the highway, the crossing required a 135-inch-diameter earth pressure-balance machine to stabilize surrounding soil and prevent highway settlement. LAN also provided program management for the broader transmission line, which included 13 construction segments and was completed in 2023.

LAN provided program management and design for 8,200 LF of 72-inch waterline through congested downtown Houston to improve water system redundancy and reliability. The project included an 874 LF, 96-inch-diameter tunnel beneath US 59 with 79-foot-deep shafts, along with roadway reconstruction, drainage improvements, traffic signals, street lighting, sidewalks, and utility relocations. LAN designed interconnections to existing 72-inch and 60-inch waterlines with no service interruptions, using detailed shutdown sequencing and specialized line-stop procedures to maintain water service.

LAN served as Program Manager and Technical Advisor for three of four construction packages on Houston’s $123 million Southwest Pump Station refill line project. The project included more than 25,000 LF of 72-inch water line through Downtown, Midtown, and Montrose to improve redundancy, reliability, and capacity for the existing water supply system. Work included roadway and drainage improvements, traffic and street lighting upgrades, and condition assessment and internal carbon fiber repairs to existing 60-inch and 66-inch prestressed concrete cylinder pipes. Construction sequencing and specialized line stops supported critical interconnections and valve installations while maintaining pump station operations.