Beneficial Use of Dredging in the Solent Project (BUDs Solent )

There is a strong desire amongst Solent Forum members to find solutions to the many barriers which are preventing the effective use of dredged material to augment Solent intertidal sites and provide other benefits associated with restoration work (especially enhanced coastal protection). The BuDS Solent project sought to address some of these issues and ran from 2017 to 2024; the Forum’s role was to manage the project and facilitate communications. For more detailed information please download the BuDs Solent Terms of Reference.

Project Aims and Benefits

The Solent Forum sought to build on past work and lead on the development of a proposal that would:

'Bring about beneficial use of dredging within one or more Solent sites, using an incrementally phased approach to scope and cost sediment sourcing and sediment receiver sites, building a system of protocols and guidance.'

More specifically the project aimed to:

Identify a set of criteria to help assess the suitability of the sites (including type of material, volume of sediment, accessibility of site, potential partnership funding, value of the site as habitat or flood and coastal management, other engineering challenges).
Identify project site(s) using the above criteria within the Solent where beneficial use would be most practical and beneficial, providing a high level of cost benefit analysis, aligning costs and benefits to regulatory bodies.
Work in partnership with a range of regional stakeholders to find solutions to known challenges based on their knowledge and existing shoreline strategies. To especially examine regulatory barriers to include smothering of existing habitat and contaminated waste concerns.
Develop a strong feasibility case for undertaking significant ‘regional flagship’ beneficial use project(s) in the Solent, and enable the implementation of that project through further phases.
Develop a love mapping system so that receiver sites can call for sediment.
Ensure that there is a collaborative exchange of lessons between the regional work of the Solent Forum and other initiatives being undertaken at a national level by parties such as the RSPB, MMO, ABPmer or The Crown Estate. Specifically to ensure that the work leads to systems (such as the love mapping system) that can be replicated and that protocols and guidance are developed.

This work built on a wealth of information much of which relates to the Solent including amongst others work from the River Hamble Harbour Authority, the University of Southampton and Lymington Harbour. It was important that the work did not replicate previous work and that the budget was used to further the delivery of beneficial use projects.

It is only possible to make real advances in the Solent if the benefits of the re-use of dredging material is really understood and costed, and these benefits are aligned to objectives of regulatory bodies and coastal managers.

Project Phases

The project comprised three phases. Download the project brief.

Phase 1 - Project Scoping and Partnership Working

Phase 1 of the project was conducted by ABPmer. This phase included a Stakeholder Workshop. The main areas of work included:

Literature review of previous Solent work, issues, challenges and constraints, including understanding of national context and drawing upon past review work.
High level review of beneficial use projects in Solent. Some detail required on criteria for assessment, and how to measure efficacy, using best practice and lessons learnt of projects elsewhere.
Create a high level strategic GIS planning map of Solent dredge locations and disposal sites and areas of potential value for recharge work.
Building a stakeholder network for the exchange of information (the project group is the core). Survey relevant Solent Authorities and stakeholder network for potential donor material and receiver sites.
High-level feasibility study including cost benefit analysis and costing of proposals to undertake beneficial use project (highlighting the range of beneficiaries).

Phase 1 Report - Project Scoping and Partnership Building, March 2018
BuDS custom map - https://abpmer.maps.arcgis.com/apps/webappviewer/index.html?id=84f75915f4d64d3f84d82e7b8923e9ba

Phase 2 – Feasibility and Stakeholder Working

Feasibility Study and Detailed Cost Benefit

Develop options for the Solent for a project(s) for beneficial use within a set time period and for preferred options to develop full feasibility plans for actual use of dredging at some key sites. Key site selected: Western Solent and Lymington Marshes. To consider whether a scheme may be a one off or one that can be repeated. This study would detail exact timings and costs of sources of sediment to match with receiver site needs. It would identify funding sources for complete projects. The beneficial costs will be firmed up so as to fully calculate cost benefit. Licences and permissions to be fully scoped ready to obtain. EIAs conducted.

Updated detailed cost benefit analysis required as well as technical analysis of recharge techniques and efficacy.
Consider Replicability – buying in the necessary kit for all sites. Benefits of scale. Pump, monitoring system.

The consultants ABPmer were contracted for this work.

The Phase 2 report was published in February 2020.

Stakeholder Working

Key stakeholders helped develop strategic guidance and a protocol. Led by the Solent Forum it built on from Phase 1 work, using workshops and stakeholder meetings. Specifically it:

Explored funding for phase 3 and developed tender material.
Developed lessons learned on maintenance dredge and disposal licensing.
Feedback the mapping of Solent dredge locations and disposal sites and areas of potential value for recharge work to national players to provide detailed matching analysis.

Phase 3 - Licencing and Operating System of Beneficial Use Dredgings’

The aim of phase 3 was to secure a Marine Licence (and any other necessary consents) that would enable the bottom placement of sediment in two locations in the western Solent (west of Lymington), by third parties operating under their own dredge disposal licence. Please see the project brief for more information. This phase started in April 2021 and concluded in Autumn 2024.

The work included a disposal site characterisation assessment prepared to inform the MMO marine licence application for two new beneficial use sites in the Lymington saltmarshes. A further short report was produced to summarise the work, the MMO response, and next steps. The report concluded that The MMO consent for the bottom placement of sediment in two locations in the Western Solent (west of Lymington) should be withdrawn, rather than allowing it to be refused, which allows the possibility of the application being resubmitted by another party in the future.

Phase 4 - Top Placement to Restore Saltmarsh Habitat

This phase will need to be costed on completion of Phase 3 and it will need to identify who will manage it and secure the funding.