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Western Dam Engineering <br /> Technical Note <br /> <br /> August 2016 <br /> <br />8 <br />manage its implementation to the large number of <br />older, aging dams that do not meet modern standards. <br />For dams that do not meet established criteria or <br />standards, most dam safety agencies are beginning to <br />allow the use of risk analysis to strategize a long-term <br />plan to prioritize repairs. However, depending on the <br />level of urgency of the identified deficiencies, short- <br />term risk reduction measures, such as operating at a <br />lowered pool or more frequent inspections, may be <br />required until the deficiencies of highest significance <br />are addressed. Risk analysis is a large topic beyond the <br />scope of this article. Look for future articles on the <br />methodology and use of risk-informed decision <br />making. <br />The Role of Dam Safety Organizations <br />Both governmental and non-governmental dam safety <br />organizations provide resources to dam owners and <br />engineers to assist in dealing with the repair and <br />maintenance of aging dams. Most federal dam safety <br />agencies and some states have developed technical <br />resources and guidance documents. Most of these <br />resources and guidelines are available to the public. <br />Engineers and owners can find links through the <br />Technical Resources, Federal Agency, and State Dam <br />Safety Program pages of the ASDSO website. ASDSO <br />also has technical and educational resources <br />specifically for dam owners on the Dam Owner website <br />at www.damowner.org. The United States Society on <br />Dams website has links to white papers on technical <br />subjects and technical publications for sale. <br />Non-governmental organizations also advocate for <br />funding for dam safety regulatory programs to provide <br />inspections of aging dams and also for grant and loan <br />programs for owners to fund the repair and <br />rehabilitation of aging dams. <br />Conclusion <br />Dams that were constructed decades ago have become <br />part of our modern landscape. Some are so small, <br />perhaps with no pool behind them, that the <br />communities that have developed downstream may <br />not even be aware the dams exist—until a flood <br />occurs. When it does, the dam is expected to stand <br />strong and withstand a force of nature that it has <br />never before experienced. In the meantime, the <br />structure may have deteriorated due to the inevitable <br />effects of aging. <br />The best way to manage the potential risks of aging <br />dams is being aware, attentive, proactive, and <br />knowledgeable. Be aware of the ways dams can <br />change over time and the potential consequences of <br />deterioration of the dam. Be attentive during <br />inspections to detect changing conditions that may <br />provide an early indication of a developing dam safety <br />condition. Perform proactive maintenance to improve <br />the longevity of the structure and limit costly repairs <br />associated with adverse conditions that are allowed to <br />progress. Be knowledgeable in understanding the <br />relative urgency of suspected deficiencies such that <br />the most severe conditions are addressed with <br />appropriate timeliness. With proper vigilance, <br />maintenance, and perhaps some justified upgrades, <br />dams can continue to perform long in the future as <br />well as they did when they were first constructed. <br />References <br />[1] Federal Emergency Management Agency (FEMA), Dam Safety in <br />the United States. A progress report on the National Dam Safety <br />Program, FEMA P-759, February 2009. <br />HTTPS://WWW.FEMA.GOV/MEDIA-LIBRARY/ASSETS/DOCUMENTS/16240 <br />[2] American Society of Civil Engineers (ASCE), 2013 Report Card for <br />America’s Infrastructure. <br />HTTP://WWW.INFRASTRUCTUREREPORTCARD.ORG/DAMS/ <br />[3] U.S. Army Corp of Engineers, National Inventory of Dams <br />HTTP://NID.USACE.ARMY.MIL/ <br />[4] United States Society on Dams (USSD), The Aging of <br />Embankment Dams. Prepared by the USSD Committee on <br />Materials for Embankment Dams. May 2010. <br />HTTP://WWW.USSDAMS.ORG/AGING.PDF <br />[5] U. S. Dept. of the Interior, Bureau of Reclamation, Dams Without <br />Filters, by Michael Gobla, <br />HTTP://WWW.DAMSAFETY.ORG/MEDIA/DOCUMENTS/FEMA/TS19_FILTER <br />SDRAINSGEOTEX_EMI2012FEB/GOBLA_DAMSWITHOUTFILTERS(1).PDF <br />[6] U. S. Dept. of the Interior, Bureau of Reclamation, Best Practices <br />in Dam and Levee Safety Risk Analyses, Chapter IV-4, Internal <br />Erosion Risks for Embankments and Foundations, July 2015 <br />HTTP://WWW.USBR.GOV/SSLE/DAMSAFETY/RISK/METHODOLOGY.HTML <br />[7] Missouri University of Science and Technology, “Origins of <br />Mechanical Compaction,” GE-441 online lecture. <br />HTTP://WEB.MST.EDU/~ROGERSDA/UMRCOURSES/GE441/ONLINE_LECTUR <br />ES/COMPACTION/GE441-LECTURE2-1.PDF <br />[8] Associate of State Dam Safety Officials (ASDSO), The Cost of <br />Rehabilitating Our Nation’s Dams, Task Committee, January <br />2009. <br />HTTP://WWW.DAMSAFETY.ORG/MEDIA/DOCUMENTS/DOWNLOADABLEDOC <br />UMENTS/REHABILITATIONCOSTS2009.PDF <br />[9] International Commission on Large Dams (ICOLD), Ageing of <br />Dams and Appurtenant Works, Bulletin No. 93, 1994. <br />[10] Pupovac, Jessica, “Aging and Underfunded: America's Dam <br />Safety Problem, in 4 Charts,” National Public Radio, October <br />2015. HTTP://WWW.NPR.ORG/2015/10/11/447181629/AGING-AND- <br />UNDERFUNDED-AMERICAS-DAM-SAFETY-PROBLEM-IN-4-CHARTS