Kennedale Balancing Reservoir Improvements Boost Capacity and Quality for TRWD

The Kennedale Balancing Reservoir project was named 2024 Pipeline Project of the Year by STI/SPFA, an organization representing the steel fabrication industry.

The Kennedale Balancing Reservoir (KBR) is a critical point in the path that water must take from the Cedar Creek and Richland Chambers Reservoirs southeast of Dallas to reach more than 2 million North Texans in the Tarrant Regional Water District’s (TRWD) service area.

Freese and Nichols has been involved with the project since its inception, designing the original 1968 plans for one cell and the Cedar Creek line, which were completed in 1972. The balancing reservoir was expanded in 1989 to add a second cell and the Richland Chambers line, followed by system upgrades completed in 2001.

Challenges Abound

The latest round of improvements focused on expanding the site to accommodate additional capacity carried by the Integrated Pipeline. They addressed a variety of needs from TRWD as they anticipated the future demands of a rapidly growing North Texas population:

  • Storage: Needed 150 MG of additional storage, increasing the facility’s capacity from 280 to 430 MG

  • Conveyance: Needed 325 MGD of additional flow, expanding from 530 to 855 MGD

  • Quality: Existing single inlet/outlet design created dead water areas that the dedicated inlets and outlets will reduce

  • Flexibility: Unable to isolate sections of the pipeline or cells for contingency operating scenarios

These enhancements required all KBR piping to be replaced to meet the upgraded operational requirements and last the District for the next 50 years.

Multifaceted Solutions

Our team designed a third cell to expand the balancing reservoir’s storage capacity, using high-density polyethylene and soil cement liner to limit infiltration from the soil embankment. The foundation for this third cell was completed in 2016, giving plenty of time for it to settle before construction, planned for some time after 2025.

The design added new lines and more inlets and outlets to improve water flow through the system:

  • 108-inch downstream pipeline known as Line J (the first Envision-rated pipeline), completed in 2014

  • 108-inch bypass line to allow TRWD to circumvent the system for maintenance or repair, completed in 2017

  • Branch lines in anticipation of the future third cell’s inlets and outlet, completed in 2025

The existing cells’ inlets and outlets were sized up to 120 inches to optimize their potential filling and draining ability. All cell overflow weirs were also modified to accommodate the new maximum flow.

TRWD performed a computational fluid dynamics (CFD) analysis of the existing cells to confirm that the new flow improved the water quality through increased water mixing and reduced detention time within the reservoir.

The piping modifications completed in 2025 added more than 25,000 LF of pipe and 28 large-diameter valves to modernize the system to meet current standards, interconnect the three major pipelines — Cedar Creek, Richland Chambers and KBR Bypass — and allow the District to:

  • Isolate source water from downstream water

  • Put source water into any of the three cells without mixing sources

  • Isolate out-of-service pipelines or cells for maintenance or repair

  • Flow water through the cells rather than store it

The new piping used concrete-encased bare steel pipe instead of the typical polyurethane-lined pipe to prevent increased corrosive potential when connecting with existing prestressed concrete cylinder pipe (PCCP). This option is a longer-lasting solution for TRWD, while providing the robust internal and external load capacity required.

Innovative Phase Sequencing

Since the KBR facility is a critical piece of infrastructure for TRWD, the design was tailored to allow TRWD to access two of the three source water pipelines throughout the project’s life without interrupting service for their wholesale customers.

The team sequenced the work into an unprecedented nine phases and collaborated with TRWD and the contractor to refine the schedule to save time and money.

The sequencing considered a variety of factors to reduce operational disruptions:

  • Seasonal demand and pumping requirements

  • Risk and safety

  • Hydrostatic testing requirements

  • Cost

  • Constructability reviews

Coordination with the project’s partners was key to maintaining sufficient water flow while protecting the construction team as they worked near active pipes.

Wins for TRWD and Beyond

When pandemic-related cost increases and supply chain issues caused initial bids to come in $10 million over budget, our team modified the design to bring the price back in line. The redesign removed the electric actuators in favor of manual valve operation, and the District repurposed them at other facilities.

The Kennedale Balance Reservoir improvements were pivotal to TRWD’s ability to meet the region’s ever-increasing future demand for water with operational flexibility and redundancy. By improving this critical node, they can now more easily maintain other parts of this complex water system.

The District can also provide their customers — including the Cities of Arlington, Fort Worth and Mansfield and the Trinity River Authority — with higher quality raw water to more easily treat, producing the best water possible for more than 2 million residents across North Texas.