From the Editor’s Desk: Infrastructure is critical
Lesley C. Ewing and Brian Caufield
Coastal Forum: Discreet working waterfronts are a lifeline for Maine fishermen
There is a full spectrum of working waterfronts along Maine’s rocky coast, from large wharves where millions of pounds of lobster cross the dock each year to much smaller wharves that are used by only one or two fishermen1 to store and maintain gear. The smaller wharves resemble the quintessential images of Maine docks — quite charming but with planks and pilings in need of repair — while some of the larger wharves are more modern, with conveyor belts and paved parking areas. The variety of working waterfronts specific to commercial fishing all provide a sense of place for fishermen and their families. Working waterfronts support fishing activity, are a beacon to return home to after a long trip at sea, and some provide the necessary access to the water that fishermen require for business.
Adapting wastewater treatment plants to sea level rise: A case study of Half Moon Bay, California
Wastewater treatment plants around the world are becoming increasingly at risk of sea level rise impacts as these facilities are typically located in low-lying areas to utilize gravity flow for influent (incoming sewage) and effluent (discharged treated sewage). As these risks become realized, treatment plant managers and decision-makers must know when and how to adapt their facilities so that this critical service goes uninterrupted. This research highlights the Sewer Authority Mid-Coastside (SAM) wastewater treatment plant in Half Moon Bay, California, as a case study of assessing vulnerability and analyzing adaptation alternatives with an approach that may be replicated for adaptation studies of other treatment plants. The vulnerability assessment is based on a worst-case greenhouse gas emissions scenario and corresponding sea level rise projection data from the California Ocean Protection Council and U.S. Geological Survey. Adaptation strategies are analyzed based on their likelihood of success considering the site-specific risks posed to the SAM plant. At only 15-20 feet elevation NAVD88 and surrounded by creeks, the SAM plant is currently at risk of groundwater inundation and creek flooding during storm events and is expected to be subject to tidal flooding with 6.6 feet of sea level rise and an annual storm event as soon as the year 2080. Nature-based solutions for sea level rise adaptation are both strongly preferred by regulatory agencies and more suitable for the SAM plant due to the surrounding sensitive habitat, including the riparian corridors, dune scrub, and coastal marsh. A phased adaptation approach will be most successful for addressing short- and long-term risks of sea level rise, with an ultimate recommendation for managed retreat of the plant to avoid inevitable flooding impacts and accommodate future sewage treatment capacity needs.
Beach nourishment provides resilient protection for critical coastal infrastructure
James R. Houston
Hurricanes this century have produced almost a trillion dollars in damages in the U.S., often to critical infrastructure that requires large costs and unacceptable times to repair or replace. There is a need for resilient protection of critical infrastructure where the protection must have the “ability to anticipate, absorb, adapt to, and/or rapidly recover from a potentially disruptive event” and be cost-effective. Coastal infrastructure can be protected by moving infrastructure back from the ocean (retreat), building protective structures, or by beach nourishment to effectively move the ocean back from the infrastructure. Retreat is very costly and highly unpopular on developed shores. Structures are expensive and lack resilience because their failure is usually catastrophic and repair slow. Beach nourishment is the favored protection option on developed shorelines because it significantly reduces infrastructure damage, provides resilient protection, and is cost effective with a high return on investment.
The aftermath of Hurricane Sandy provided an example of the tremendous reduction of infrastructure damage due to beach nourishment. Dr. Stewart Farrell, director of the Coastal Research Center in New Jersey, reported: “It really, really works. Where there was a federal beach fill in place, there was no major damage — no homes destroyed. Where there was no beach nourishment, the destruction was complete. Older homes were ripped from foundations and tossed about.” A post-Sandy analysis showed that Corps of Engineers’ beach nourishment projects saved an estimated $1.3 billion in avoided damages.
Beach nourishment provides resilient protection. It is partially self-healing, because during a storm some of the sand moves to offshore bars where it causes waves to break and reduces infrastructure damage, and then much of it returns to shore after the storm passes. It can be repaired relatively rapidly by use of a mobile dredge to replace net sand loss. It is a highly adaptable approach to climate change because its rate of sand placement can be varied to raise profiles to offset increased sea level rise. Beach nourishment pays for itself as nice, wide beaches sit in readiness to protect critical coastal infrastructure from storms, while in the meantime, tourists typically generate more than $100 in taxes annually to local, state, and the federal governments for every $1 these governments invest in beach nourishment.
Disposable or readily relocatable infrastructure to aid managed coastal retreat
Angus D. Gordon
Infrastructure can become a major determinant as to whether a defense or a retreat strategy is adopted at a coastal location. A significant investment in expensive networks of roads, water supply, and sewerage systems, along with power and telecommunications distribution infrastructure, can tip the defense/retreat debate and the associated cost-benefit analysis in favour of a defense approach. Often the increasingly expensive and sophisticated infrastructure servicing a coastal community has evolved over time, from simple beginnings. However, with upgrades and expansions coastal communities have become totally dependent on complex centralized systems that are vulnerable to disruption by erosion, shoreline recession, and/or oceanic overwash. For a strategy of managed retreat to be practical and achievable at any location, a policy which encourages self-sufficient or low-cost infrastructure that can be readily abandoned or relocated is desirable. There is also a need to re-think the forms of coastal subdivision layout and infrastructure provision that are most amenable to progressive retreat.
Resilient edges — holistic coastal protection and lessons learned
Ian McRae and Jim Remlin
This paper will provide the reader with a planning and engineering framework that addresses a broad range of dynamic coastal issues which are increasingly exacerbated by climate change. The exploration of our recent work in Charleston, South Carolina, will demonstrate how strategies can be implemented at a site-specific scale to tackle interconnected issues impacting community, infrastructure and environment. This will highlight the importance of how layered protection, ecological sensitivity, and holistic thinking to address coastal systems can facilitate innovative and thoughtful approaches to resilient coastal edge protection, resulting in effective long-term solutions that align with community character, robust ecosystems, and integrated infrastructure. Our involvement in a wide range of sea level rise projects has highlighted core principles to achieve coastal resilience. These include the need for rigorous site analysis to identify vulnerable communities and services, and proactive development of solutions to mitigate projected threats while supporting critical stormwater and transportation infrastructure. The goal is to prepare for the future without undermining current economic opportunity, quality of life, and connection to waterfronts.
Sea level rise planning for resilient coastal infrastructure in California’s coastal zone
Climate change is here. Impacts already demonstrate the interconnected nature and rippling effect of extreme events in wildfires, droughts, floods, and erosion — from coastal to inland areas. Coastal California is especially at risk to impacts of sea level rise, with the potential to displace over 100,000 people and put billions in property value at risk by 2050. Sea level rise in concert with large storms can far exceed damages wrought by other natural disasters in California history, and damage will occur more frequently and extensively in the same coastal areas. The California Coastal Commission, in partnership with local governments, can address the vulnerabilities of communities to climate impacts, including sea level rise, through the land use policies and zoning ordinances that comprise their Local Coastal Programs (LCPs). As infrastructure often guides and directs land use development, so can infrastructure adaptation lead communities in preparing for the impacts of sea level rise. The Coastal Commission’s 2021 guidance, titled “Critical Infrastructure at Risk: Sea Level Rise Planning Guidance for California’s Coastal Zone,” offers a blueprint of policies for adapting transportation and water infrastructure to sea level rise in the coastal zone. This paper will describe key messages of the new guidance and present case studies of land use plans that demonstrate how some California communities are already creating a pathway for sea level rise adaptation. LCPs in San Francisco, Half Moon Bay, Pacific Grove, and Morro Bay exemplify a few of the many ways communities can plan to make transportation and water infrastructure more resilient to sea level rise using phased adaptation, nature-based projects, and asset relocation. There is no one single solution for all communities, but every community can benefit from implementing better requirements for risk assessment, risk reduction, and risk communication through their land use policies and regulations. By better communicating about the risks and restrictions on shoreline properties, local governments can educate stakeholders about sea level rise hazards and encourage public participation in adaptation planning that creates more resilient critical infrastructure.
ASBPA’s 15th annual photography contest