[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-676520-105":59,"doc-detail-676520-en":129},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":122,"head_meta":124,"extra_data":126,"updated_unix":128},105,"en","technical-manual-overtopping-protection-for-dams-preface","Technical Manual - Overtopping Protection for Dams - Preface","","This document explains why and when dam overtopping protection may be reconsidered as a viable alternative after the original design is reevaluated due to incidents, unusual loads, new information, or revised risk-based criteria. It outlines the decision process, emphasizing failure-risk considerations and the need for analysis of dam and appurtenant features under baseline and modified conditions. It also reviews common materials and highlights limited public standardization, so designers should rely on testing, manufacturer recommendations, and independent analysis.",{"@graph":69,"@context":121},[70,84,104],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/technical-manual-overtopping-protection-for-dams-preface/676520/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":98,"encodingFormat":97,"isAccessibleForFree":99,"interactionStatistic":100},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/technical-manual-overtopping-protection-for-dams-preface/676520.png","ImageObject",300,407,{"name":92,"@type":93},"404brain","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-04",true,{"@type":101,"interactionType":102,"userInteractionCount":4},"InteractionCounter",{"@type":103},"ViewAction",{"@type":105,"mainEntity":106},"FAQPage",[107,113,117],{"name":108,"@type":109,"acceptedAnswer":110},"Why might the original design of a dam be reevaluated?","Question",{"text":111,"@type":112},"It can be reevaluated due to incidents or unusual loads, newly available information, refinement of design requirements or guidelines, adoption of risk-based criteria, or as part of a regular dam safety program.","Answer",{"name":114,"@type":109,"acceptedAnswer":115},"What key risk must be considered before choosing overtopping protection?",{"text":116,"@type":112},"The potential risk of failure of the protection system, which could quickly lead to a full breach of the dam; this risk must be incorporated into decision-making qualitatively or quantitatively.",{"name":118,"@type":109,"acceptedAnswer":119},"What alternatives does the document compare overtopping protection against?",{"text":120,"@type":112},"It references improving the service spillway, imposing a reservoir restriction, raising the dam crest, or constructing an auxiliary spillway, noting that overtopping protection should not be chosen lightly.","https://schema.org",{"og:url":83,"og:type":123,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":125,"canonical":83},"index,follow",{"doc_id":127,"site_id":62},676520,1793775980,{"code":4,"msg":5,"data":130},{"doc_id":127,"user_id":131,"nickname":92,"user_avatar":132,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":133,"file_id":134,"file_url":135,"file_type":136,"file_size":137,"view_count":4,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":138,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":128,"read_time":143},1099529839291,"https://ap-avatar.wpscdn.com/davatar_6f874abed73319feea01a86fa6f0fab8","FEMA’s mission is to support our citizens and first responders to ensure that as a nation we work together to build, sustain and improve our capability to prepare for, protect against, respond to, recover from and mitigate all hazards.  \nThe U.S. Department of the Interior protects America’s natural resources and heritage, honors our cultures and tribal communities, and supplies the energy to power our future.  \nThe mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public.  \nOn the cover.—Vesuvius Dam (Ohio) after overtopping protection placement of roller compacted concrete. Construction was completed in 2001 (Reclamation)  \nPreface  \nThe original design of a dam may be reevaluated for a number of reasons, including the occurrence of an incident or unusual load, the availability of new information, the refinement of certain design requirements or guidelines, the adoption of risk-based criteria, or as part ofa regular dam safety program. During this process, the design flood may be revised, resulting in a flood that is larger than was used for the original design. In many cases, analysis may show that the revised flood will result in the dam being overtopped due to insufficient reservoir storage and/or release capabilities.  \nThere are many methods available for accommodating larger revised floods. However, some of the more common methods, such as increasing reservoir storage by raising the dam crest or increasing release capability by increasing the spillway discharge capacity, can often be cost prohibitive or impractical. To address this situation, new design approaches have been developed that may allow for the dam to be safely overtopped. The design and construction of overtopping protection for dams is increasingly being viewed as a viable alternative to larger spillways as developing watersheds or changing hydrology produce higher peak flows and the need for additional spillway discharge capacity for existing dams.  \nOvertopping protection may be an attractive alternative because of its potential economic advantages and may offer an economical solution to a hydrologic deficiency that would otherwise not be addressed. Maintaining the existing hydraulic conditions at the dam to the extent possible is also increasingly important as downstream river corridors are developed in close proximity to the channel. This document assumes that a hydrologic deficiency exists at a dam and that traditional approaches to safely accommodate a larger design flood have first been investigated.  \nThe decision to pursue overtopping protection for an existing dam must give strong consideration to the potential risk of failure of the protection system, which could quickly lead to a full breach of the dam. This is especially true for embankment dams, in the sense that a small defect or design flaw could lead to catastrophic failure once the embankment is exposed to the overtopping flow. An evaluation of this type of risk must be incorporated into the decision-making process, whether qualitatively or quantitatively.  \nA decision to use overtopping protection in place of improving the service spillway, imposing a reservoir restriction, raising the dam crest, or constructing an auxiliary spillway cannot be made lightly. Overtopping protection should generally be reserved for situations with some combination of very low annual probability of occurrence (e.g., 1 in 100), physical or environmental constraints on constructing other methods of flood conveyance, and prohibitive cost of other alternatives; or where downstream consequences of dam failure are demonstrated  \nto be low. A careful analysis of all potential failure modes for the dam and appurtenant features must be performed for both the existing (baseline) conditions and for the proposed modified conditions.  \nAlternatives for overtopping protection may use a var","cbCaiur9u0v66DFs","https://ap.wps.com/l/cbCaiur9u0v66DFs","pdf",22682204,462,"English","# Preface\n## Reasons for Reevaluating Dam Design\n## When Overtopping Protection May Be Chosen\n## Risk and Failure Mode Evaluation\n## Common Overtopping Protection Materials\n## Model Testing and Need for Consistency","[{\"question\":\"Why might the original design of a dam be reevaluated?\",\"answer\":\"It can be reevaluated due to incidents or unusual loads, newly available information, refinement of design requirements or guidelines, adoption of risk-based criteria, or as part of a regular dam safety program.\"},{\"question\":\"What key risk must be considered before choosing overtopping protection?\",\"answer\":\"The potential risk of failure of the protection system, which could quickly lead to a full breach of the dam; this risk must be incorporated into decision-making qualitatively or quantitatively.\"},{\"question\":\"What alternatives does the document compare overtopping protection against?\",\"answer\":\"It references improving the service spillway, imposing a reservoir restriction, raising the dam crest, or constructing an auxiliary spillway, noting that overtopping protection should not be chosen lightly.\"}]","Technical Manual - Overtopping Protection for Dams - Preface | PDF",1164]