Technical Manual

Tens of thousands of conduits through embankment dams in the United States are aging and deteriorating. These conduits often were poorly constructed and are not frequently inspected, if at all. Deteriorating conduits pose an increasingly greater risk for developing defects that can lead to embankment dam failure with each passing year. In an effort to deal with this problem, this document has been prepared to collect and disseminate information and experience that is current and has a technical consensus. This document provides procedures and guidance for "best practices" concerning design, construction, problem identification and evaluation, inspection, maintenance, renovation, and repair associated with conduits through embankment dams. Most of the available information on these topics was reviewed in preparing this document. Where detailed documentation existed, it was cited to avoid duplicating available materials. The authors have strived not to reproduce information that is readily accessible in the public domain. This document attempts to condense and summarize the vast body of existing information, provide a clear and concise synopsis of this information, and present a recommended course of action. This document is intended for use by personnel familiar with embankment dams and conduits, such as designers, inspectors, construction oversight personnel, and dam safety engineers. In preparation of this document, the authors frequently found conflicting procedures and standards in the many references they reviewed. Where conflicts were apparent, the authors focused on what they judged to be the "best practice" and included that judgment in this document. Therefore, this document may be different than some of the various participating agencies' own policies. Embankment dams, regardless of their size, create a hazard potential from the stored energy of the water they impound.