Channeling Progress, Building Futures: USACE, Japan MLIT Strengthen Partnership via Tunneling and Water Management Exchange

TOKYO, JAPAN – In a world where complex water resource challenges demand innovative and resilient solutions, the U.S. Army Corps of Engineers (USACE) and Japan's Ministry of Land, Infrastructure, Transport, and Tourism (MLIT) convened in Tokyo from May 19-21, 2026, for their 17th technical exchange.

This long-standing partnership, a cornerstone of the USACE Pacific Ocean Division's (POD) International and Interagency Services (IIS) program, underscores a shared commitment to advancing engineering solutions for global and local challenges.

This year's exchange centered on a critical area of infrastructure: large-scale water conveyance tunnels. As USACE explores advanced solutions for flood risk management across the United States, Japan’s world-renowned expertise in tunneling technology offers invaluable insights for U.S. Civil Works projects.

A Resilient Partnership for the Indo-Pacific

The collaboration was highlighted during the opening session, where Mr. Kenichi Kawamura, Japan's Deputy Minister for International Projects, and Mr. Jose Sanchez, Director of Engineering and Business for the USACE Pacific Ocean Division, spoke on the strategic importance of the bilateral relationship.

"This gathering represents far more than a routine meeting—it embodies a vital partnership forged over nearly four decades of collaboration," said Mr. Sanchez. "As we face unprecedented challenges like the impacts of severe weather events and the strain of aging infrastructure, I am confident that through our continued collaboration and transparent knowledge sharing, USACE and MLIT will continue to develop the innovative solutions required for a resilient future.”

Mr. Sanchez emphasized that this partnership provides a model of stability and technical leadership for the entire Indo-Pacific region, directly supporting the broader engagement priorities and strategies of U.S. Indo-Pacific Command (USINDOPACOM) and U.S. Army Pacific (USARPAC).

Bridging International, Federal, and Local Expertise

Demonstrating a commitment to whole-of-government solutions, USACE invited key non-federal partners actively facing significant water management issues to participate in the delegation. This inclusion allowed for a unique convergence of federal leadership, local government officials, and international engineering pioneers. Throughout the exchange, the USACE delegation focused on exploring Japan’s massive underground flood discharge channels to adapt these advanced engineering strategies for U.S. watersheds. To support this effort, Japanese industry leaders Kajima and Shimizu Corporations provided technical deep-dives into cutting-edge Tunnel Boring Machine (TBM) and Shield Tunneling technologies.

Meanwhile, local partners like Mr. Scott Elmer, Chief Partnerships & Programs Officer for the Harris County Flood Control District in Texas, which serves the third most populated county in the nation, studied how these large stormwater tunnels could reduce flood risks in highly urbanized environments. Additionally, Ms. Katie Koester, City Manager for the City & Borough of Juneau, Alaska, considered flood risk mitigation and tunnel options specifically for the Mendenhall Valley, a high-priority initiative requested directly by the Assistant Secretary of the Army for Civil Works.

"The complexity of delivering meaningful flood risk reduction projects in highly urbanized environments like Harris County requires us to consider new and innovative solutions," noted Mr. Elmer. "This technical exchange not only showcased those solutions but also broke down knowledge barriers between our agencies. These closer relationships will allow for meaningful collaboration to provide the public with efficient and effective infrastructure."

For Ms. Koester, the opportunity to evaluate potential solutions for the Mendenhall Valley alongside top federal engineers proved equally critical. "It has been an invaluable experience. I have not only learned about technology and innovation that applies directly to our local projects, but I’ve also had the opportunity to discuss and workshop those ideas with USACE experts," she shared. "It gave me a tremendous appreciation for the professionalism and expertise USACE brings to solve some of the most complex engineering challenges our communities are facing."

Shared Expertise, International Standards

The bilateral benefits of this enduring partnership were further highlighted during an office call with Mr. Masayoshi Hirose, the Vice-Minister for Engineering Affairs at MLIT.

Emphasizing that the challenges of ensuring infrastructure resilience in the face of severe weather and urbanization are shared globally, Vice-Minister Hirose reflected on the continuous mutual learning between the two nations. He specifically highlighted the “My Timeline” component of Japan’s Flood and Emergency Warning System, noting it was designed after consulting with USACE experts regarding effective engagement with local levels of government.

This shared knowledge, he noted, demonstrates how continued collaboration allows both organizations to innovate and establish new international standards for engineering and public safety.

Engineering the Future

The technical discussions were anchored by presentations from experts like Dr. Georgette Hlepas, Principal Geotechnical Engineer for USACE, who detailed the current state of large stormwater tunnel conveyance systems in the U.S., sparking a dynamic discussion on how to adapt Japanese technologies to American projects. The dialogue extended to other critical areas, including early warning systems, impact mitigation, and the development of international standards for managing hydrologic risks.

The event concluded with site visits to some of Japan's most impressive water infrastructure projects, including the Metropolitan Outer Area Underground Discharge Channel – a massive subterranean system that has become a global benchmark for flood risk reduction.

Technical discussions were held with both design engineers and construction contractors. USACE leaders observed that MLIT remains actively engaged in large-diameter tunnel construction for flood mitigation, noting that their means and methods are not dissimilar to those currently being included in USACE studies and designs. Furthermore, the delegation noted that MLIT experiences similar challenges related to cost growth and schedule delays during construction—primarily stemming from geological complexities. Recognizing these shared hurdles has paved the way for future collaborative discussions on project delivery, risk management, and schedule optimization.

This technical exchange highlights the USACE Civil Works and engineering programs in action, reaffirming the immense value of maintaining this professional relationship and technology exchange agreement with MLIT. By bringing together international, federal, and local partners to find innovative solutions for the nation's most pressing infrastructure needs, USACE ensures that from the floodplains of Texas to the glacial valleys of Alaska, the knowledge shared in Tokyo will help build a safer and more resilient future.