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North Dakota | Montana | South Dakota | Minnesota | Wyoming
Lonni Fleck, PE
Location Williston, ND
Specialty Water Systems, Trenchless Technology

Lonni Fleck, PE

Principal Engineer | President
A Lifelong learner, Lonni Fleck brings her curiosity and ability to connect people together for the benefit of clients and the company.

Growing up, Lonni often took things apart, figured out how they worked, and then put them back together. And though dismantling was entertaining,  bringing everything together was where she found the most enjoyment. Her problem-solving ability, love of math, and understanding that investments should have returns led Lonni to a civil engineering career. With over 20 years in the field, Lonni has worked with clients, helping solve infrastructure and utility challenges, including designing the dream, helping find funding, and watching the goal built into a reality to make communities stronger and serve people better. In 2009, Lonni was appointed to the Interstate Engineering Board of Directors. She uses her abilities to bring people together to lead and grow the firm as it prepares for its next 40 years.

“Lasting relationships matter most, whether with clients, coworkers, or peers. I want to see our company be where clients and team members feel welcome and supported.”

  • Education: BS in Civil Engineering, North Dakota State University
  • Professional Registrations: Professional Engineer - North Dakota & Montana | LSI - North Dakota
  • Affiliations: North Dakota ACEC DEQ Liaison
Outside of Interstate Engineering

Lonni is an avid traveler, embracing moments to read, rest, and enjoy her family. Whether camping and boating in the summer or traveling to warmer places when North Dakota winter sets in, she finds time to continue learning and participating in the moment.

  • Recommended Read: The 10X Rule by Grant Cardone
  • Best Concert: Smashing Pumpkins
Project Management
Public Engagement
Risk Management