Review of Approaches and Recommendations for Improving Resilience of Water Management Infrastructure: The Case for Large Dams

35 A 6 Task Committee (TC) on Infrastructure Impacts of Landscape36 DrivenWeather Change of the American Society of Civil Engineers 37 (ASCE) was formed during 2012–2013. At that time several events 38 related to improving infrastructure resilience for water management 39 were front-page news across the nation. For instance, around 2009 40 the Tennessee Valley Authority (TVA) reported that the height of 41 four of their dams would be raised by more than 1 m (Hydroworld 42 2009). Although the scientific reasoning behind the height increase 43 was not clearly known, media reports suggested that the projected 44 increased risk of greater flooding from global climate models 45 (GCM) may have driven this decision. It should be noted that de46 spite its wide use of adaptation policies, there exists considerable 47 uncertainty and debate around the use of GCM projections for 48 large-scale infrastructure for water management (e.g., Hossain et al. 49 2012; Kundewicz and Stakhiv 2010, Anagnostopoulos et al. 2010; 50 Stephens et al. 2010, van Haren et al. 2012; Hourdin et al. 2016). 51 Other studies, such those on stormwater infrastructure, also show 52 that the use of GCMs may lead to a design mismatch (Moglen and 53 Vidal 2014). 54 At the forefront of this ASCE TC is the resilience of large infra55 structure, particularly large dams and artificial reservoirs that form 56 the cornerstone of most regulated river systems of today. An im57 portant consideration for this study is that if it is cost prohibitive to 58 fortify a large system comprising dams in a river basin, would it be 59 possible to design these systems and their upgrades to fail grace60 fully? Graceful failure is not a new concept (Hossain et al. 2015a; 61 the first report of this TC). Many dams have fuse plugs in redundant 62 spillway systems that are designed to fail when a shock flood 63 wave occurs upstream. This concept, however, is subject to the 64 availability of open land downstream that can be inundated with 65 floodwaters. The ASCE TC recently conducted a survey of expe66 rienced water managers regarding the critical issues facing the na67 tion’s large water infrastructure (Hossain et al. 2015b). This survey 68 was the second in the series of reports produced by this TC. It re69 vealed that the engineering profession may need greater academic– 70 practitioner collaboration to develop more use-inspired curriculum 71 for future engineers who will have to solve interdisciplinary prob72 lems not experienced before (Hossain et al. 2015b). Therefore, if 73 historical management practices prioritized either water quality or 74 quantity over the other, moving forward, water management will 75 have to consider and balance both. For example, the eutrophication 76 of water bodies near agricultural land is traditionally treated solely 77 as a nonpoint pollution runoff problem rather than also as a water 78 management issue. Practitioners now recognize that both aspects 79 need to be addressed jointly in management practices to address 80 emerging challenges. Many practitioners also feel that the emer81 gence of new contaminants or changes to water quality due to vary82 ing quantity brought by a drought or a flood will likely add to the 83 cost of water delivery systems—an issue that is yet to be included 84 in water management research and practice. 85 During the October 2015 flooding in South Carolina, a record 86 amount of rainfall caused mass disruption for the entire state. 87 However, the biggest casualty was not life or property. Rather, it 88 was the disruption of freshwater supply and the wastewater treat89 ment system that were knocked out in the immediate aftermath of 90 the flooding (Good 2015). This resulted in a shortage of safe drink91 ing water for large sections of the state. The next big casualty was 92 the increased vulnerability of 36 large dams in the state that were 93 overtopped during the flooding (Good 2015). These dams, accord94 ing to the American Society of Dam Safety Officials (ASDSO), 95 were already in need of repair and posed a high risk downstream. 96 These events suggest that trying to make one entity of an infrastruc97 ture system more resilient (e.g., power distribution, transportation,