Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?

Abstract Wetland restoration is an increasingly popular nature‐based method for flood risk mitigation in coastal communities. In this study, we present a novel method using hydrodynamic modeling and harmonic analysis to quantify wetlands' ability to reduce future nuisance flooding. The method l...

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Main Authors: M. W. Brand, H. L. Diefenderfer, C. E. Cornu, M. A. McKeon, C. N. Janousek, A. B. Borde, T. D. Souza, M. E. Keogh, C. A. Brown, S. D. Bridgham
Format: Article
Language:English
Published: Wiley 2025-03-01
Series:Earth's Future
Online Access:https://doi.org/10.1029/2023EF004149
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author M. W. Brand
H. L. Diefenderfer
C. E. Cornu
M. A. McKeon
C. N. Janousek
A. B. Borde
T. D. Souza
M. E. Keogh
C. A. Brown
S. D. Bridgham
author_facet M. W. Brand
H. L. Diefenderfer
C. E. Cornu
M. A. McKeon
C. N. Janousek
A. B. Borde
T. D. Souza
M. E. Keogh
C. A. Brown
S. D. Bridgham
author_sort M. W. Brand
collection DOAJ
description Abstract Wetland restoration is an increasingly popular nature‐based method for flood risk mitigation in coastal communities. In this study, we present a novel method using hydrodynamic modeling and harmonic analysis to quantify wetlands' ability to reduce future nuisance flooding. The method leverages a hydrodynamic model calibrated to present day data and was run for a range of future sea‐level rise (SLR) and wetland restoration scenarios to quantify changes to tidal harmonic amplitudes and phases. The harmonic constituents are used to generate water surface elevations over a time period of interest (e.g., one year) and compared to critical exceedance thresholds such as levee elevations. Then, changes to nuisance flooding are calculated by counting the number of hours critical thresholds are exceeded under different SLR and wetland restoration scenarios. We applied the method to Coos Bay, Oregon, USA as a test case. We found restoration reduces the number of hours nuisance flooding occurs in downtown Coos Bay from 15 hr (present day conditions) to 0 hr (fully restored condition) under median SLR (82 cm by 2100). Restoration had spatially variable impacts on reducing peak flood elevations with minimal impacts near the estuary mouth and greatest impact 32 km inland. The effectiveness of restoration was heavily dependent on future SLR. Restoration was maximally effective in 2050 under all SLR scenarios, less effective in 2100 under median SLR, and not effective under high SLR. Modeling results suggest increased tidal prism and accommodation space are driving restoration‐associated reductions in tidal amplitudes.
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spelling doaj-art-09997bb35b3f485db74f85332f3c7d8c2025-08-20T02:08:27ZengWileyEarth's Future2328-42772025-03-01133n/an/a10.1029/2023EF004149Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?M. W. Brand0H. L. Diefenderfer1C. E. Cornu2M. A. McKeon3C. N. Janousek4A. B. Borde5T. D. Souza6M. E. Keogh7C. A. Brown8S. D. Bridgham9Louisiana State University Baton Rouge LA USAPacific Northwest National Laboratory Coastal Sciences Division Sequim WA USAInstitute for Applied Ecology Corvallis OR USAPacific Northwest National Laboratory Coastal Sciences Division Sequim WA USAOregon State University Corvallis OR USAPacific Northwest National Laboratory Coastal Sciences Division Sequim WA USAUniversity of North Carolina Chapel Hill NC USAOregon State University Corvallis OR USAPacific Ecological Systems Division, US EPA Newport OR USAUniversity of Oregon Eugene OR USAAbstract Wetland restoration is an increasingly popular nature‐based method for flood risk mitigation in coastal communities. In this study, we present a novel method using hydrodynamic modeling and harmonic analysis to quantify wetlands' ability to reduce future nuisance flooding. The method leverages a hydrodynamic model calibrated to present day data and was run for a range of future sea‐level rise (SLR) and wetland restoration scenarios to quantify changes to tidal harmonic amplitudes and phases. The harmonic constituents are used to generate water surface elevations over a time period of interest (e.g., one year) and compared to critical exceedance thresholds such as levee elevations. Then, changes to nuisance flooding are calculated by counting the number of hours critical thresholds are exceeded under different SLR and wetland restoration scenarios. We applied the method to Coos Bay, Oregon, USA as a test case. We found restoration reduces the number of hours nuisance flooding occurs in downtown Coos Bay from 15 hr (present day conditions) to 0 hr (fully restored condition) under median SLR (82 cm by 2100). Restoration had spatially variable impacts on reducing peak flood elevations with minimal impacts near the estuary mouth and greatest impact 32 km inland. The effectiveness of restoration was heavily dependent on future SLR. Restoration was maximally effective in 2050 under all SLR scenarios, less effective in 2100 under median SLR, and not effective under high SLR. Modeling results suggest increased tidal prism and accommodation space are driving restoration‐associated reductions in tidal amplitudes.https://doi.org/10.1029/2023EF004149
spellingShingle M. W. Brand
H. L. Diefenderfer
C. E. Cornu
M. A. McKeon
C. N. Janousek
A. B. Borde
T. D. Souza
M. E. Keogh
C. A. Brown
S. D. Bridgham
Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?
Earth's Future
title Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?
title_full Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?
title_fullStr Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?
title_full_unstemmed Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?
title_short Can Restoring Tidal Wetlands Reduce Estuarine Nuisance Flooding of Coasts Under Future Sea‐Level Rise?
title_sort can restoring tidal wetlands reduce estuarine nuisance flooding of coasts under future sea level rise
url https://doi.org/10.1029/2023EF004149
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