Puget Sound Energy – Lacey Washington

Puget Sound Energy (PSE) needed to install a new high-pressure gas line along a state highway in Lacey, Washington. The state initially required PSE to install their new gas line as close as possible to the outer edge of the right-of-way with no lane closures. Upon initial investigation, it was discovered this area was highly congested with existing utilities making design much more complicated. The project would cost significantly more, and the construction would impact the highway with continuous lane closures for several months. PSE worked with the state, to no avail, communicating concerns about the impossibility of installing the new high-pressure gas line in conformance with the state’s requirements.

2D CAD existing utilities + proposed gas line alignment (solid yellow line in road)


To solve the impasse, a 3D utility model was created using collected Subsurface Utility Engineering data. GEO.works imported data from utility investigations and exported data directly into CAD to create a 3D utility model in AutoDesk Civil 3D and create simulations using NAVISworks. 3D modeling was key to helping communicate project constraints and impacts to the state. PSE was given permission to locate the gas line in an area where construction could be streamlined, and traffic disruptions would be limited to night-time hours for a 6-week duration. The 3D CAD model was helpful for designers who adjusted the vertical elevation of the gas line to avoid conflicts with existing utilities and drainage facilities.

3D CAD rendering of proposed PSE pipe (yellow line in center) with existing utilities and storm drainage


3D CAD close-up rendering of proposed PSE pipe (yellow line in center) showing how vertical placement of the gas line was adjusted to avoid conflicts with existing utilities and storm drainage


When PSE opened construction bids, prices came in below the Engineer’s estimate. The contractor was able to anticipate each existing utility and drainage line during excavation. When the contractor performed the work, production rates doubled what they had bid, construction duration was cut in half.

Installing the PSE’s new gas line