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Sea Level Rise and Tidal Barrages

  • 1.  Sea Level Rise and Tidal Barrages

    Posted 05-10-2023 10:31 PM

    Projected levels of sea level rise will put New York, Miami, Boston, and dozens of other population centers at risk of chronic flooding (link) in the next few decades. Tidal barrages could offer protection from flooding and also produce renewable energy in some locations, albeit with environmental costs. Are we be planning for such structures now? Should we be?



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    William McAnally Ph.D., P.E., D.CE, D.NE, F.ASCE
    ENGINEER
    Columbus MS
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  • 2.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-11-2023 08:12 AM

    This should definitely be in the mix as one of the well-thought-out responses. The most impressive example, albeit focused mainly on power production is the Swansea Blue Lagoon scheme - http://www.tidallagoonpower.com/projects/swansea-bay



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    Joe Wagner P.E., D.NE, M.ASCE
    Senior Dredging Engineer
    HDR, Inc.
    Jacksonville FL
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  • 3.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-11-2023 12:00 PM

    I would think that experts in that type of power-generating technology (using tides to generate power) would have well-established guidelines regarding suitability and applicability.  For example, in many areas, I would think that the tidal water surface elevation difference might not be sufficient to generate sufficient benefits to offset the costs of ecological and navigational disruptions. 



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    Michael Bloom, PE,
    ENV SP, BCEE, CFM (he/him)
    Sustainability Practice Manager
    5engineering, LLC
    Houston TX
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  • 4.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-11-2023 01:46 PM

    What "costs of ecological and navigational disruptions" would the Swansea Blue Lagoon scheme - Swansea Bay - Tidal Lagoon

     create? The removed bay bottom (covered by a dike) is replaced by a sloping dike, which only increases the area and structure for the existing ecosystem. As for navigation, that has always occurred outside the proposed basin footprint. 



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    Joe Wagner P.E., D.NE, M.ASCE
    Senior Dredging Engineer
    HDR, Inc.
    Jacksonville FL
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  • 5.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-16-2023 05:42 PM

    Yes, tide height matters, but flood depth could generate energy, too (for short periods of time).  Clean water power turbines might be economic even for once or twice a year flood events.



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    Sarah Simon P.E., ENV SP, M.ASCE
    Founding Partner
    Ipswich MA
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  • 6.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-16-2023 05:42 PM

    We need to be innovative and design for systems, but we alway need to be careful about the date of references on the web for examples of new tech.  Unfortunately, this Swansea project has posted nothing since 2020, so the local politics (as mentioned in other comments) may have played a part in scuttling it.  The nearly 10 km2 area and volume of the lagoon may have taken too much territory.  Combining it with fresh water flood control could provide another value stream.

    If a manufacturer was planning a low head (10 meters?) saltwater turbine when the project was proposed more than a decade ago, that may never have made it to market (or been proven infeasible for corrosion or demand volume)



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    Sarah Simon P.E., ENV SP, M.ASCE
    Founding Partner
    Ipswich MA
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  • 7.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-17-2023 11:05 AM

    The Swansea Scheme is very much alive and moving forward. There were discussions with various firms and established funded. 

    I have no idea what you are referring when you state "Unfortunately, this Swansea project has posted nothing since 2020."



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    Robert Wagner P.E., D.NE, M.ASCE
    Senior Dredging Engineer
    HDR, Inc.
    Jacksonville FL
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  • 8.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-11-2023 12:01 PM

    I'm actually working on resilient design in Miami and am the engineer of record for the premiere park sea level rise retrofit for City of Miami. I've been involved with the planning for the USACE $6 Billion "Back Bay Plan" which originally envisioned a 20-ft wall to protect Miami from storm surge, but neglected to factor in precipitation or the environment so it was sent back to the drawing board by the Public.  We have to factor in the environmental costs and build this into our projects at the forefront (Day Zero). We cannot pay Peter and rob Paul, that is not how this next century will work. I see a lot of engineers thinking in silos, and I want to encourage dropping these false boundaries and collaborating across the board with other disciplines, including architects, scientists, university collaborations, and also folks with detailed historical, geologic, and local expertise in these areas. Including hydrology and hydraulics. The cities you list are ALREADY experiencing this chronic flooding very often, daily in some cases. Three weeks ago, Fort Lauderdale (20 miles from Miami) received 24-28 inches, what is being called the 1,000 year storm by the weather channel etc - and it really disrupted the South Florida fuel supply from Port Everglades, ruined Houses and Businesses (including our office), severed communities and left residents stranded in floating cars. The flooding you speak of is HERE, and it will take "death by 1,000 cuts" type approach to prepare our cities and communities for day-to-day life now and in the future. I'd love to hear more about innovative solutions you describe, but please consider the environment as your #1 shareholder/client. 



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    Patrick Shearer P.E., M.ASCE
    Engineer IV
    RES Florida Consulting, LLC Dba E Sciences
    Miami FL
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  • 9.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-13-2023 03:51 PM
    Patrick,
    This relates directly to strategic rewinding (see rewinding earth podcast for one example) With a combination of tidal barriers and rewinding by shrinking the human footprint in places of less value to urban real estate but of high value to biodiversity, a project could be self-mitigating and a win/win. However, this takes planning by engineers and restoration proponents at a effective yet workable scale as well as a commitment to long-term O&M.




  • 10.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-11-2023 01:47 PM

    I see tidal barrages as tool in the tool kit but not a panacea.  As a renewable power source, tidal power per unit of energy is far more expensive than wind or solar, so it's still a niche technology at best. See link. There's a also the issue of political and societal will for projects of scale that will mitigate the effects of sea level rise on our coastal communities. The lack of will, or consensus that we have a looming problem, will prevent the long-term planning and preparation needed for projects that could conceptually combine mitigation with energy generation. 



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    Mitch Winkler P.E., M.ASCE
    Houston, TX
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  • 11.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-15-2023 11:14 AM

    I have to agree with Mitch, "consensus or lack of will" and sometimes lack of knowledge on the part of the people who approve funding or political pressure will halt if not completely stop a valuable project from proceeding. I believe engineers have the ability to accomplish many things however without the support or conviction of the politicians - nothing gets done. Heck after Sandy occurred it was difficult to get consensus on updating our floodplain regulations even though the State was mandating it!



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    John Giardiello P.E., M.ASCE
    Port Saint Lucie FL
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  • 12.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-16-2023 11:42 AM

    Thank you @William McAnally for starting this thread. Thank you all for sharing these examples. ASCE recently posted an article on a similar topic so I wanted to share it here:

    How recent research on rising sea levels could impact coastal design
     



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    Tirza Austin
    Senior Manager, Online Community
    American Society of Civil Engineers
    1801 Alexander Bell Drive
    Reston, VA 20191
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  • 13.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-16-2023 05:41 PM

    Good reference (Construction Coverage). 



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    Sarah Simon P.E., ENV SP, M.ASCE
    Founding Partner
    Ipswich MA
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  • 14.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-22-2023 10:04 AM

    As a former professional diver who is planning on getting back into the field once I retire from the Air Force and get my degree and FE complete, I'd also like to suggest that there might be an extreme shortage of competent labor in this area as well. The commercial dive school I attended shut down because of VA fraud and a culture of inappropriate levels of drinking. When I was working in the inland sector of the field I saw numerous examples of willful deviations from design criteria. I know engineers have a PM mindset against scope creep but a great design doesn't translate if implementation is unrealistic. No labor supply, no project, no electricity. It all can't be done from spud barges with cranes. Some fixes take finesse.



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    Bradley Snyder S.M.ASCE
    Quality Assurance
    Joppa MD
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  • 15.  RE: Sea Level Rise and Tidal Barrages

    Posted 05-24-2023 04:45 PM

    Some good info on this topic. Referring to many such discussions posted earlier on the Collaborate forum – it is encouraging that Warming Climate continues to dominate world attention. This process is perhaps heading towards the extent of irreversible warming that becomes apparent if one pays attention to the long-term Sun-Earth heat energy balance and entropy. Such a looming scenario is absolutely horrific – asking for launching global coordinated strategy – by riding over petty differences and conflicts. Hope we are heading in that direction.

    • One of the consequences of warming process – as we coastal scientists and engineers are fond of – is Sea Level Rise (SLR). And addressing the Consequences of SLR through smart planning and engineering interventions.

    • As humans ventured more out into the sea – Building Cities, Townships and Port & Harborwe positioned ourselves into a very vulnerable domain. Nature has nothing to do with it – it was the looming disaster of our own making.

    • Therefore coastal planners and coastal zone managers are in hotbed and must be very diligent to re-define and re-demarcate the development of coastal zones – in order to avoid being the cause of human-made disaster in the future.

    • Installing Flood Barrier Systems is just one of the option. How far can one go? Riding on top of the SLR – there have been or are going to be enhancement of storm surge, tide and wave activity and tsunami onslaughts on the coastal zone. How about costs, immediate and long-term environment impacts, and risks? These are difficult questions that must be addressed. Barrages fitted with tide and wave energy generation mechanisms – can be cost saving – but how about impacts on aquatic lives.

    • I have looked into the current shares of global of energy sources. This is how it stands now: fossil fuel 81%; nuclear 6%; hydro-energy 2%; solar, wind and other 11%. Although, these shares are rapidly changing, the distribution immediately indicates that we are far off – far from our dependence on fossil fuels. Among these, fossil fuel and nuclear power are the ones that add to the Sun-Earth heat balance – in other words, enhancing the warming process of Earth – others are neutral from this perspective.

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    Dr Dilip K Barua, PhD

    Website Links and Profile