The Pacific Northwest's Premier Water Contractor

Slayden is a leader in the Pacific Northwest heavy civil construction industry, primarily focusing on water and wastewater infrastructure. Slayden is built on solid values, hard work, and a commitment to getting the job done right. The success of our company is best expressed by staffing a safe workplace with experienced employees and a committed management team. Our approach provides steady growth in work volume, successful career development for personnel, and an extensive list of satisfied clients for nearly 40 years.

Strength through Experience and Knowledge

Through our unwavering dedication to customer service, Slayden is one of the most respected contractors in the Pacific Northwest and northern California, providing our clients with heavy civil and environmental construction services that include industry-leading preconstruction services, quality,  and safety practices. Our projects include water and wastewater treatment facilities, dams, fisheries, renewable energy/hydro, river restoration, and other heavy civil projects.

Same Company – Same People

Slayden is a wholly owned subsidiary of MWH Constructors, with added resources and the same dedicated team committed to providing you the highest level of service.

This is an exciting development for MWH Constructors and our very talented and dedicated employees around the globe. We have worked hard to grow a world-class portfolio of water and wastewater infrastructure projects. Our partnership with Oaktree will enable us to further improve and expand our services to our customers. With the additional resources of this new partnership, our future is bright.
-Blair Lavoie, Chief Executive Officer and President of MWH

Our Services

Preconstruction Services

Planning and Coordination




Value Engineering




Construction Services

Project Controls

Subcontractor Outreach

Commissioning and Startup

Electronic O&M Manuals

Project Closeout

Risk Management

Project Management

Design Management



Alternative Delivery Methods


Construction Manager At Risk (CMAR)



Progressive Design-Build

Flexible Pricing Approaches

Other Services

Community Outreach

Small Business Participation

Core Ideology


To build great people, projects, and relationships.


People Matter  |  We look after people unconditionally with character, honesty, and integrity.

Team Unity  |  We work as a team to exceed expectations while displaying loyalty and commitment.

Solutions Driven  |  We adjust positively to challenges encountered.

Future Focused  |  We make decisions with the long term in mind.