- On 29th June 2017
- In Dredging, Project Management, Sediment Management, Water Management
- By William
Morgan Marine is a family-run boatyard and marina in Brightlingsea, situated on the north bank of Brightlingsea Creek, a tributary of the River Colne with its confluence located close to the Colne Estuary. Founded in 1971, Morgan Marine maintains and has a longstanding reputation for new and used boat sales, boat brokerage, chandlery, mooring facilities and maintenance services, supplying the recreational boating community around Essex, the east coast of the UK and northern Europe.
With its continued success, Morgan Marine has aspirations to further develop the existing marina and facilities into the ‘Colne Marina’. Based on an envisaged business development plan and client feedback, the development aims to:
– Provide an additional 78 berths
– Expand and modernise new and existing facilities, including: washroom facilities, boat storage and a bespoke pontoon system offering electrical hook-up and WiFi connection
– Develop shore side services, including: marine maintenance, haulage and a state of the art closed-loop vessel wash down facility.
Morgan Marine have tasked Exo with the design and management of the development of the Colne Marina. Following an early option appraisal, cost analysis and constructive discussion with the Client, we spent the 20th-23rd June on site collecting sediment samples, as required by the Marine Management Organisation (MMO) licensing team.
The development is to involve the capital dredge of approximately 30,000m3 of predominantly silty CLAY, in order to achieve a bed profile that will allow the provision of a range of berths that are accessible at all states of the tide. Part of this arising sediment is to be incorporated into the on-going USAR works being undertaken by the Brightlingsea Harbour Commissioners and will be beneficially used in the restoration of local intertidal mudflat and saltmarsh habitats. See www.exo-env.co.uk for more information regarding the USAR project.
Matching sediment sources and sinks is a major factor in identifying suitable beneficial reuse opportunities. Additionally, being a capital dredge, it is imperative that the physicochemical characteristics of the source material are well understood.
Consequently, samples from varying depths on site (source) and from within the proposed restoration sites (sink) were required, thereby ensuring suitability and compatibility of the sediments for beneficial use. To aid with the works and sample collection, geotechnical specialists AF Howlands were contracted, bringing their experience and terrier drilling rig to the team. Mounted on a floating pontoon, the drill rig obtained cores of up to 3m in depth, whilst the Exo Surveyor got her first taste of monitoring work (and mud!) collecting all surface samples from the restoration sites throughout Brightlingsea Creek. By the end of the monitoring campaign, and despite the fierce sun being broken only by thunderstorms, all samples were obtained to specification and submitted to the National Laboratory Service (NLS) for analysis.
Following satisfactory results, the engineered design of the development can be further detailed, whilst the restoration sites can start to be prepped this winter as we head back in towards brushwood fascine installation mode…