On-Call Rehabilitation Large Diameter Water Lines — City of Houston, TX

Aurora supports the City of Houston Drinking Water Operations (DWO) group on a multi-year on-call large diameter water line rehabilitation contract which involves repairing, replacing, or rehabilitating the City of Houston's existing large diameter infrastructure.

Aurora serves as the Lead Technical Engineer providing DWO engineering and operations staff with design, field, and coordination support. This includes developing the design and strategy for repairing, replacing, and rehabilitating large diameter water lines (both above and below ground), isolation valves, air valves, and other appurtenances that have experienced failures or require rehabilitation. Aurora also supports the City with emergency repairs involving major pipeline rupture leaks or failures.

Aurora helps DWO evaluate and implement new and innovative rehabilitation methods to employ in their system. Some of those efforts include supporting the City with rehabilitating various LDWLs, including the City of Houston's first implementation of Spray-in-Place-Pipe (SIPP) and the development of internal documents that summarize the latest rehabilitation technologies available for the City's water system.

2025 Water Distribution and Transmission System, Project 35 — NHCRWA, Houston, TX

Project 35 consists of a 30 to the 24-inch transmission water line that expands the North Harris County Regional Water Authority’s (NHCRWA) delivery of surface water throughout its service area. The project’s primary purpose is the ongoing pursuit of surface water conversion in compliance with regulatory mandates. Project 35, is a series of projects scheduled to be in service by the end of 2025, as a part of NHCRWA’s planned 2025 Water Distribution and Transmission System.

Aurora was selected to perform the preliminary engineering route study. Project 35 consists of approximately 7,500 LF of 30-inch and 26,000 LF of 24-inch transmission line, and approximately 9,500 LF of 12-inch distribution line. These lines supply surface water to ten different groundwater plants. Project 35 is at times referred to as the “third loop” because it establishes a third loop in NHCRWA’s main transmission system. Aurora recommended phasing the project into four construction contracts for implementing the project:  35A, 35B, 35C and 35D.

Upon completion of the route study, NHCRWA assigned Aurora as the Program Manager for Project 35. This entails a variety of responsibilities including scope and fee negotiations, overall design management including technical reviews, regulatory coordination and approvals, and performing constructability reviews. As Program Manager, Aurora is assessing project risks, scheduling, budget monitoring, invoice reviews, progress meetings, design submittal reviews, and real estate acquisition assistance. It was necessary to acquire all easements prior to advertising each of the four projects for bid and construction because project funding came from the Texas Water Development Board.  As a result, real estate acquisitions quickly became the governing schedule milestone. Aurora is performing a key role in the acquisition efforts by leading the acquisition team through pipe alignment and easement decisions, developing design adjustments for finalizing easement negotiations, performing quality reviews of easement documents, and tracking and monitoring acquisition pursuits.

108” Northwest Transmission Water Line, Smith Road to Bellow Falls — City of Houston, TX

This project is part of the Northeast Transmission Water Line, a multi-year project designed to carry treated surface water produced by the planned expansion of the City of Houston’s Northeast Water Purification Plant. This project consists of approximately 10,000 LF of 108” water transmission line along the multiple City of Houston easements from Bellow Falls to Smith Road. One of the main challenges encountered in this project includes the constructability issues in placing the proposed 108” line in close proximity to an existing 84” parallel line. Aurora is providing engineering support to the lead design firm on the analysis of the maximum allowable load on the existing 84” line and minimum separation distances between the two lines. Aurora is also designing the interconnect details to the existing 84” line. Other engineering services provided include a review and analysis of the project’s geotechnical report, constructability reviews on project submittals, a review of the project’s design details, and coordination with vendors on pricing for major items.

108” Water Line, UPRR to John Ralston — City of Houston, TX

Aurora Technical Services was selected by the City of Houston as the prime to design almost 8,000 LF of 108” water transmission line. The water line has numerous challenges that include: installation of the new line adjacent to an existing 84” water line (that cannot be taken out of service), several tunnels requiring close attention to the potential impact to railroad operations and the BW 8 main lanes.  Furthermore, this project will involve a number of critical crossings of roadways and petroleum/gas pipelines. The estimated construction cost for the project is between $22M and $28M. The ongoing design includes coordination with HCFCD, TxDOT, Harris County and HCTRA, as well as several Municipal Utility Districts.

84" Water Transmission Line, IH-45 to the west of Sharmon Rd — NHCRWA, TX

Aurora was selected to design a project that is part of North Harris County Regional Water Authority’s (Authority) 2025 water supply system plan, a multi-year project which will carry water from the Northeast Water Purification Plant (NEWPP) to the Authority’s new SH 249 Regional Pump Station and Storage Facility. This project consisted of a meter station with disinfection and approximately 9,300 LF of 84-inch water transmission line along various easements and a high voltage transmission line CenterPoint Corridor. The major challenges to this project included a fault crossing, close proximity to many high-voltage transmission line towers and tunneling under Beltway 8. During the initial design phase of this project, Aurora was tasked to evaluate meter station locations and potential routes. The final route reduced the tunnel length under Beltway 8 from 2,000 LF to approximately 500 LF, reducing project risk and cost. The bid construction cost for this project is $34M, and the project was bid 4 months ahead of schedule.

60” DIP along Dolly Wright, Dubois and Victory from the Acres Home Pump Station to Inwood Park — City of Houston, TX

This project consisted of approximately 6,800 LF of 60” WL along mostly a two-lane asphalt roadway (in a 50-foot-wide ROW) with rather deep roadside ditches. The design included a discharge connection to one of the Owner’s largest regional pump stations.  Due to the service area of the pump station, the connection had to be designed to phase the work in such a manner as to minimize the required shutdown period of the pump station.

The project alignment extended through a historical area of town that was considered economically depressed.  Complicated the design was to need to replace the existing water distribution line located within the ROW, while at the same time avoiding disturbing a parallel 21” deep gravity sewer line recently installed a few years earlier. A key consideration was the trench wall stability of the proposed 60” line when parallel to the 21” sanitary. In a few areas to protect the manholes, solid shoring was required.

Another challenge was maintaining adequate drainage while the 60” line was under construction. The project alignment was along a roadway that was over 1 foot higher than the abutting properties. During design, alternatives to discharging the groundwater was evaluated to ensure the adjacent residents’ homes were not flooded during construction.

36” Water Line Relocation at IH-45 and SH-96 — Gulf Coast Water Authority, League City, TX

GCWA owns an existing 39" prestressed concrete water line that is the main supply line for the City of League City. A segment of the existing line crossed underneath an overpass bridge on IH-45 where construction was underway for the expansion of the highway. Field investigation conducted by TxDOT revealed a conflict between the bridge expansion’s pile foundation and embankment. Due to the criticality of the water line to the City of League City and the potential for future impacts on the I-45 bridge in the event of line failure, the water line had to be relocated outside the proposed bridge embankment. Aurora was responsible for evaluating the optimal relocation alignment that avoided interruption of ongoing highway construction, and conflicts with existing and proposed utilities and the development of the design for selected alternatives, which involved the design of tunnels across IH-45 and SH-96.  The design of the relocation needed to take into account conflicts with existing and future utilities, such as future storm sewers, gas pipelines and water distribution mains, while avoiding interference with ongoing highway construction. ATS was also responsible for construction phase services and construction management.