Portland, OR

Natgun Water Storage Tanks


DN Tanks (formerly Natgun) designs and constructs prestressed concrete liquid storage tanks. The tanks are American Water Works Association (AWWA) D110 prestressed wire-wound concrete tanks that incorporate precast concrete panels. SGH developed a seismic design procedure for the domes and peer reviewed the tank designs. We used the procedure to design a number of tanks constructed in high seismic regions.

SGH provided the following services:

  • Reviewed seismic designs for prestressed concrete tanks
  • Assessed compliance to governing codes, including the California Building Code, American Society of Civil Engineers’ Minimum Design Loads For Buildings and Other Structures (ASCE 7), AWWA D110, American Concrete Institute 350.3, and the International Building Code
  • Developed a procedure for designing precast and cast-in-place concrete domes for use in high seismic areas
  • Evaluated the new procedure by performing detailed finite element analyses
  • Conducted laboratory testing of a cored wall to assess the bond strength of the steel diaphragm within the composite wall cross-section
  • Applied the procedure to the seismic design of several tanks

Project Summary



Completion Date
New Construction
Structures | Applied Science & Research | Advanced Analysis
Infrastructure & Transportation
DN Tanks
Specialized Capabilities
Seismic Engineering | Computational Mechanics | Physical Testing

Key team members

Mehdi Zarghamee
Mehdi Zarghamee
Senior Principal
David  McCormick
David McCormick
Senior Principal
Dominic  Kelly
Dominic Kelly
Senior Principal