Reducing Damage to Underground Utility Infrastructure During Excavation

A recent white paper unveils the danger and the financial cost of hitting underground infrastructure during excavations. The paper, prepared by Geoff Zeiss and Dr. Sakura Shinoaki and published by the Geospatial Information & Technology Association, states that there are between 400,000 and 800,000 incidents per year in the United States (roughly one or two per minute), presenting an annual burden of up to $100,000 billion on the U.S. economy. Over the past 20 years, those incidents have resulted in nearly 2,000 injuries and more than 400 deaths. “Clearly something can be done to reduce the risk for construction workers and the public,” write the authors.

Locating and Mapping Underground Infrastructure

The paper touts the benefits of two key components in solving this monumental issue: Use recent advances in technology to locate infrastructure that isn’t documented on existing plan sets and then record the information in the form of digital maps. Several examples of the benefits of these maps were given.

Government agencies and construction firms are recognizing that accurate models of underground infrastructure bring practical benefits to construction projects. For example, a consulting firm hired to study the Sydney Light Rail Extension project concluded that if a complete and reliable 3D map of underground infrastructure had been available at the project planning stage, the project could have been completed at least one and a half years sooner. The Alabama Department of Transportation saved $10 million by using 3D modeling of underground utilities on a major highway interchange project … For a highway revitalization project in Cedar Falls, Iowa a 3D model of underground utilities was created before the start of the design phase. 200 utility conflicts were found prior to beginning construction, enabling the project to complete on schedule and 3% underbid.

These examples show that an accurate model of underground utilities can not only reduce the risk of damage, project delays, and budget overruns but can also reduce the cost of infrastructure by designing it in a way that reduces unnecessary and costly moving of utilities.

Significant Return on Investment

The paper states that providing accurate underground utility information during the early stages of design can reap huge benefits. As evidence, return on investment (ROI) studies of subsurface utility engineering (SUE) surveys were applied to highway construction projects since the 1990s. One of the first, conducted by Purdue University in 1999, estimated that requiring SUE on highway projects would have saved $1 billion annually. The most recent study by the Pennsylvania Department of Transportation estimated an ROI of $11.39 for every $1 spent. The largest contributor to cost savings from SUE was a more than 40% reduction in project relocation costs due to having accurate information on the location of underground infrastructure.


The authors reviewed a wide range of international initiatives to develop programs for underground infrastructure information and compiled 25 recommendations that governments, organizations, and property owners can use to address the challenges associated with damage to underground utilities. Some examples include “Digitalizing the capture, sharing and updating of location information about underground infrastructure.” That includes one or multiple databases of data and “a single map of all underground infrastructure including utilities, telecom, and unknown and abandoned equipment is provided via a browser or handheld device.” The authors also recommend providing stakeholders access to underground infrastructure location information throughout the construction project life-cycle, “beginning with a SUE survey prior to engineering design which is accessible by planners, engineers/designers, construction contractors, and those responsible for operations and maintenance.”

According to the authors, having accurate information about underground utilities not only reduces damage and the associated costs, injuries and fatalities and results in more projects finishing on-time and on-budget, but also significantly reduces the cost of maintenance. And developing and maintaining an accurate map of underground infrastructure “has potential benefits for other use cases beyond construction such as utility outage management, disaster planning, and emergency response.”

You can download the full white paper here.