Integrating Engineering with Ecology and Natural Resource Economics to Emphasize Coastal and Habitat Resilience
WODCON XXIII - Dredging is changing - The Practice. The Science. The Business.
V. Magar, K. Searcy-Bell, S. Goetz, R. Mandel, S. Copp Franz, B. Suedel, D. Hayes, J. King
"Background - As societies around the world are confronted by increasingly severe weather events, the need for additional investment into ecological sustainability and resiliency has never been more important. Local, regional, and national communities are seeking ways to address the combined pressures of global climate change, expanding human populations, increased coastal vulnerability, and limited resource availability and distribution. Improved sustainability requires the successful integration of multiple disciplines and fields of practice, including the integration of conventional engineering with more inclusive and innovative engineering approaches such as Working with Nature (WwN, PIANC 2018) and Engineering with Nature(r) (EWN(r)), and the use of Nature-Based Solutions (NbS) in design. Coined in 2010 by the US Army Corps of Engineers (USACE), EWN supports more sustainable practices, projects, and outcomes through alignment of natural (green) and conventional (gray) engineering practices to sustainably deliver economic, environmental, and social benefits. WwN, a PIANC (www.pianc.org) initiative, and EWN(tm), a USACE initiative (https://ewn.erdc.dren.mil/) integrate conventional engineering with ecology and natural resource economics to emphasize improved habitat and biodiversity along with coastal and habitat resilience. Successful integration of green and grey design concepts requires multidisciplinary assessments that foster creative engineering and NbS alternatives while recognizing public interests, environmental and engineering constraints, and costs. Cost considerations for major projects must expand beyond the comparison of capital costs for project alternatives and must begin to factor short- and long-term benefits, sustainability, environmental value, and opportunities for cost avoidance. Consistent policy and regulation established at the federal, state, and local levels can further support the establishment, coordination, and implementation of WwN projects. Need for harmonized regulatory approaches Incompatible project timing and volume inconsistencies between dredging projects and beneficial use projects often discourage beneficial use. Risk of contamination is another factor that can substantially hinder sediment reuse. These barriers must be overcome if beneficial use of dredged material is to become standard practice. A more holistic evaluation of beneficial use and disposal options is needed, considering short-term and long-term benefits, ecosystem services, and costs. Policy changes are currently being realized globally as evidenced by WwN and EWN(r). Regulatory changes also are being realized. For example, in the United States, the 2020 Water Resources Development Act (WRDA 2020) now requires consideration of value" when considering waterborne projects and the management of dredged material - signifying how global trends are evolving toward more sustainable and environmentally beneficial outcomes. Thousands of projects worldwide have successfully used millions of cubic meters of dredged material for beneficial use applications since the concept was introduced in the 1970s. While most projects have been technical successes - some were unable to achieve sufficient financial success to be sustainable. Despite documented successes - currently less than 40% of dredged material in the US is used beneficially (Searcy Bell et al. 2021). Limited federal - regional - and local budgets discourage the use of more costly beneficial use alternatives - even if those alternatives are more environmentally sustainable - reduce overall operations and maintenance costs - and are more closely aligned with nature."
Keywords: Beneficial Use, sediment, sustainability, resiliency, Working with Nature