By: Ann Boeholt and Camille Felkins, �鶹TV��վ Senior Environmental Managers

Adaptive management is often described as a best practice, but its value is most evident when projects face conditions no plan can fully anticipate. This case study — shared at the — illustrates how flexibility, collaboration and observation helped guide a project in a complex wetland system on Tribal lands.

Salmon, Sovereignty and Fish Passage

Pacific salmon have long been central to the cultures, economies and lifeways of Pacific Northwest Tribes. Over time, however, state highway infrastructure contributed to fragmented aquatic systems, limiting access to historic spawning and rearing habitats.

Since the 1990s, the Washington State Department of Transportation (WSDOT) has worked with Tribes and the Washington Department of Fish and Wildlife to identify and address fish passage barriers across the state highway system. This work accelerated significantly following a 2013 permanent injunction that established a 2030 deadline for replacing approximately 400 barriers — those expected to reconnect roughly 90 percent of the targeted habitat. Today, this ongoing, collaborative effort focuses on restoring connectivity within waterways that often intersect sensitive environmental and regulatory settings.

A Culvert, a Wetland and Changing Conditions

One such project along U.S. Highway 101 involved installing a fish‑passable culvert in 2025 to restore natural stream function. Adjacent to the site was a mosaic wetland system within the Quinault Indian Reservation.

Shortly after construction, a high‑flow event caused nearby Harlow Creek to overtop its banks. Water moved across the newly graded wetland, forming overflow channels and flow paths not anticipated in the original restoration design. While the culvert performed as intended, the surrounding wetland — newly planted and not fully stabilized — responded rapidly to these conditions.

These changes introduced challenges. Permit requirements included specific restoration and stabilization goals designed to meet water quality standards, while the wetland’s natural response made a rigid, prescriptive approach difficult to apply. In addition, the stream’s new flow path through the wetland meant that no in-stream work could occur until the following summer construction window. Any potential retrofit work within the wetland or stream would also require careful coordination, as these conditions coincided with the federal government shutdown in fall 2025.

Managing Complexity Through Collaboration

Responding effectively required close coordination among WSDOT, Tribal partners and multiple regulatory agencies. Additional constraints, including narrow in‑stream work windows and limited agency availability, reinforced the need for an approach that was both practical and adaptive.

Rather than attempting to force the system back to its original design assumptions, the project team proposed a flexible, adaptive path forward.

Letting the System Inform Solutions

In the near term, the team implemented minimal erosion‑control best management practices to protect the site while limiting additional disturbance. At the same time, they committed to ongoing monitoring to better understand how the wetland functions under post‑construction conditions.

Monitoring showed that the new overflow channels aligned with the wetland’s mosaic character. While the final design solution is still evolving, the longer‑term approach shifted toward stabilizing those channels within the floodplain — supporting ecological function and permit objectives while working with natural processes.

Together, these decisions reflect how adaptive management can support effective outcomes in dynamic environments by allowing real‑world conditions to inform design, permitting and long‑term performance.

Join Us at NAWM

We will share additional lessons learned from this case study during our presentation, “Implementing effective adaptive management to meet project goals in the face of unforeseen and changing conditions,” at the on Thursday, April 30, at 11 a.m.

If you are attending NAWM, we invite you to join the session and connect with us or continue the conversation on LinkedIn.

Chicago Transit Authority Red and Purple Line Modernization Project

Chicago Transit Authority (CTA) is investing in a more resilient and efficient transportation system with its $2.1 billion (RPM)—one of the largest transit investments in the agency’s history. The project includes replacing four century-old stations along Chicago’s busiest transit corridor with larger facilities that are ADA (Americans with Disabilities Act) compliant. The new stations feature wider platforms, better lighting, improved security, real-time information boards, more reliable train service, less crowded trains and platforms and a more aesthetically pleasing environment for pedestrians.

As part of the Walsh-Fluor Design-Build team, �鶹TV��վ provided civil engineering services, including roadway design, traffic maintenance, signal design, utility coordination, drainage design, site layouts, and grading, as well as electrical and lighting design.

“Every day, millions of Chicagoans rely on the city’s transit system to get where they need to go. Supporting our long-time client, �鶹TV��վ was proud to collaborate with CTA on delivering a safer, more reliable transit system,” said Tom Price, �鶹TV��վ Infrastructure President. “Sustainability, preservation, and innovation were woven into every decision made, resulting in a project that truly honors Chicago’s past, while building a resilient, efficient transit future.”

Building a modern transit system

Construction on Phase One began in 2019 and included updates on two major areas—the and the (LBMM) section. With millions of passengers relying on the Red Line every year, updating these lines was critical to making CTA’s transit system more reliable and efficient.

In 2021, CTA celebrated the completion of the Red Purple Bypass. This milestone allowed northbound Brown Line trains to pass over Red and Purple Line tracks—eliminating a critical bottleneck and allowing for more frequent service.

CTA hit another major milestone in 2025 with the completion of the LBMM portion of the project, which involved reconstructing four stations and replacing all elevated track and support structures along 1.3 miles of the Red Line.

Working within one of the nation’s most spatially constrained urban corridors presents unique challenges. �鶹TV��վ helped CTA employ highly adaptive planning strategies to overcome numerous complexities throughout this project. To keep trains running on time, our team utilized creative solutions to sequence construction and implement temporary systems, including two fully functional temporary stations that served the public for years before the final stations were finished. �鶹TV��վ’ team even helped relocate a century-old building to allow critical track realignment—a decision that demonstrated thoughtful engineering and respect for the city’s architectural heritage.

“Together with CTA and our industry partners, �鶹TV��վ designed every element of construction planning to reduce inconvenience and minimize disruption to people’s daily routines,” added Price. “�鶹TV��վ is proud to have contributed to this landmark project that will be utilized by millions of passengers in the years to come.”

Working collaboratively with CTA, our team contributed to this massive transit line upgrade through:

• Roadway and alley rehabilitation: �鶹TV��վ designed plans for all impacted streets and alleys within the project limits and reconstructed all impacted sidewalks to meet Chicago Department of Transportation (CDOT) standards with ADA compliant ramps at all temporary and permanent locations.
• Collaborative planning and permitting: �鶹TV��վ was responsible for all utility coordination on the project, including identifying potential conflicts early in the design-build process. By maintaining regular contact with utilities throughout the project, �鶹TV��վ made proactive communication and coordination a top priority. Our team worked extensively with Walsh-Flour to facilitate communication with the Department of Buildings, CDOT, and the Office of Underground Coordination to keep the project running smoothly.
• Digital and technical knowledge: �鶹TV��վ’ modeling experts created and maintained a dynamic digital terrain model for all surface drainage, roadway vertical geometry and ADA design grades. Our design included extensive OpenRoads work—driving efficiencies and schedule. �鶹TV��վ was an early adopter of OpenRoads software to create dynamic 3-D models.
• Enhanced safety and lighting: With a deep understanding of CTA’s and CDOT’s requirements, �鶹TV��վ designed all exterior lighting for the RPB and LBMM sections, as well as power feeds for relay houses, aesthetic lighting, and temporary and permanent lighting for station facades.
• Creative drainage solutions: �鶹TV��վ designed the Stormwater Management Plan, incorporating CTA’s requirements for collecting and storing runoff. Infiltration trenches and storage tanks were utilized, which eliminated surface runoff contributing to the city sewer system.
• Collaborative construction delivery: �鶹TV��վ coordinated with Walsh-Fluor, Stantec, and associated subconsultants to coordinate timing on the overall sequence of design packages.

At a glance

CTA’s Phase One investment, one of the largest design-build projects undertaken by CTA

When this corridor was first built, making it one of the oldest in the CTA system

Built with modern architecture and ADA accessibility features

Historically significant Vautravers building moved for track realignment