Mitigating Geotechnical Challenges Associated with Marshland Restoration in the San Diego Bay

DOI

10.2991/978-94-6463-258-3_68How to use a DOI?

Keywords

Slope stability; restoration; factors of safety; berm failure

Abstract

Coastal marshes provide many benefits to local communities, including increased habitat, coastal protection, and recreational use. The Otay River Estuary Restoration Project (ORERP) aims to restore disturbed marsh wetlands for the benefit of fish, birds, and other coastal species native to habitats at the south end of San Diego Bay. The project involves the excavation of material from the San Diego Bay National Wildlife Refuge floodplain and the transport and placement of that material in an existing solar salt pond (Pond 15) to establish and restore tidal marshland.

This paper addresses the geotechnical challenges associated with the earthwork involved in the ORERP and the use of Rocscience software in the development of the design. The challenges with restoring marshland within Pond 15 lay in the earthen berm separating San Diego Bay from the hypersaline water within the salt pond. To construct tidal marshland within Pond 15, the pond must first be drained of brine before fill can be placed and a portion of the perimeter berm removed to safely expose the restored marsh to the bay’s tides. Draining the brine will change the conditions that influence the stability of the perimeter berm of Pond 15. If the berm were to fail, brine would flow into bay waters, resulting in adverse impacts to bay habitats and associated wildlife. To address the potential impacts associated with berm failure, geotechnical analyses were performed to develop guidance for all phases of the restoration project. To mitigate risks of berm instability, Slide2 was used to iteratively assess berm enhancements, as well as different approaches to pond draining, so that acceptable factors of safety would be achieved during and after construction.

Copyright

© 2023 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Sam Giannakos
AU  - Andrew Barrett
AU  - John Laplante
AU  - David Cannon
PY  - 2023
DA  - 2023/11/08
TI  - Mitigating Geotechnical Challenges Associated with Marshland Restoration in the San Diego Bay
BT  - Proceedings of the Rocscience International Conference  (RIC 2023)
PB  - Atlantis Press
SP  - 741
EP  - 750
SN  - 2589-4943
UR  - https://doi.org/10.2991/978-94-6463-258-3_68
DO  - 10.2991/978-94-6463-258-3_68
ID  - Giannakos2023
ER  -