Are we ready for more dam removals in the United States?

When unlocking rivers results in building more infrastructure: A group mental model shares lessons from weir remediation in the United Kingdom

“…Legislating to ensure weir infrastructure is owned would ensure greater accountability, transparency, and minimize barriers to action. Weir ownership policy is important to ensure proactive planning to identify weirs that are safety risks and promote public safety (Vahedifard et al, 2021 discuss this in relation to the United States) and is particularly important in the UK and Europe where many weirs are already beyond their projected lifespan (Habel et al, 2020). Currently, thousands of weirs have not been inventoried or evaluated for age or safety (see Jones et al, 2019).…”

“…The calls also have potential implications and relevance to people in other countries in Europe and beyond. Weirs (or low-head dams) are some of the most abundant and impactful structures to freshwater ecosystems (Morden et al, 2022), and there is a growing movement, particularly in Europe and North America, to remove weirs from rivers (Vahedifard et al, 2021). In Europe and North America, many weirs were constructed in the 18th and 19th centuries for mill, log, or industrial ponds, to divert water for irrigation or flood control, or to alter water levels for boat navigation (EA, 2013;Oliver & Grant, 2017;Smith et al, 2014).…”

“…Many such weirs have exceeded their intended lifespan, do not meet human or environmental safety standards, or no longer deliver their intended purpose (e.g., diverting water for mills or industry). Existing weirs that exceed their lifespan are the primary targets of removal initiatives for reasons of public safety and liability, such as drowning or structural failure risk reduction, and to restore water flows and movement of sediments, materials, and species that have otherwise been altered for more than a century (Doyle et al, 2008;Oliver & Grant, 2017;Pejchar & Warner, 2001;Smith et al, 2014;Vahedifard et al, 2021).…”

NEPA and climate change: consideration of climate mitigation and adaptation in infrastructure review processes

“…At the same time, climate change is projected to have substantial impacts on infrastructure systems. For instance, coastal flooding and sea level rise are already damaging critical transportation, energy, and wastewater treatment infrastructure located along the coast (Azevedo de Almeida and Mostafavi 2016), increased likelihood of extreme rainfall events has increased the risk of dam failures (Vahedifard et al 2021), and drought-induced fires have led to preemptive power shutdowns in the United States (US) and Australia (Mitchell 2013, Abatzoglou et al 2020. Ensuring long-term viability of infrastructure thus requires climate adaptation, defined as 'adjustment to actual or expected climate and its effects' (IPCC 2014).…”

Hydroelectricity Modeling for Low‐Carbon and No‐Carbon Grids: Empirical Operational Parameters for Optimization and Dispatch Models

“…Models frequently deploy large amounts of hydropower in very high RE scenarios: for example, in models of New Zealand, Portugal, and New England (USA), hydropower is employed extensively (sometimes more than 50% of generation) to balance loads (Cochran et al., 2014; Deason, 2018; Dimanchev et al., 2021; Krajačić et al., 2011; Mason et al., 2010). These studies vary in the extent to which they rely on new hydropower capacity; when they do, there are serious questions about how and whether the models sufficiently account for serious physical and socioenvironmental constraints on capacity buildout, particularly in light of increasing dam removals in the United States (Vahedifard et al., 2021), including powered dams (Amos, 2014; Pohl, 2002). Even when hydropower provides a relatively small fraction of total generation, it often provides important load balancing services for grid stabilization (Child & Breyer, 2016; Elliston et al., 2012; Jacobson et al., 2018; Rasmussen et al., 2012).…”