Preparation of Subsurface Investigation Plans for Embankment Dams and Levees

The civil engineering community has adopted the ethical concept of “do no harm”, as referenced in the fundamental canons of the American Society of Civil Engineers’ (ASCE) Code of Ethics to “hold paramount the safety, health and welfare of the public”. Dams, identified in the National Infrastructure Protection Plan as Critical Infrastructure, are part of a national strategy to utilize capabilities across this entire community to prevent, protect against, mitigate, respond to, and recover from the threats and hazards that pose the greatest risks. This concept is particularly crucial when analyzing the impact
of collecting subsurface data to inform designs utilized in dam construction, modification, and rehabilitation projects.

A high level of consideration and care in planning and implementing investigation procedures for dam projects is required due to the risks associated with certain drilling, grouting, instrument installation, and borehole abandonment techniques that may result in structural damage. It is important for planning and field personnel to possess a thorough understanding of the known and/or inferred subsurface conditions present and recognize the potential for certain types of drilling activities to contribute to and/or induce problems and to mitigate these issues by applying established guidelines and standards in addition to engineering judgment when developing and conducting subsurface investigations.

This article outlines federal and Western state standards and regulations currently used for subsurface investigations, including the requirements thereof.