River Tywi

Large Scour Hole Exposing Gas PipelineRock Roll Mattress InstallationBrushwood and Rock Rolls In PlaceAccretion of Sediment Over Rock Roll Mattresses
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Accretion of Sediment Over Rock Roll Mattresses

Salix were awarded a Design & Build contract to prevent further erosion of a section of the riverbank and reinstate a scour hole threatening a high pressure gas pipeline on the River Tywi.

The Tywi is designated a Special Area of Conservation (SAC) and SSSI and is one of Europe’s finest sea trout fisheries. Due to the sensitive nature of the site within an intertidal zone, it required a solution that would look as natural as possible whilst providing permanent long-term erosion protection.

A combination of Rock Mattresses and brushwood fill further up the bank allowed accretion of sediment to build up quickly covering the permanent bioengineering solution effectively. Rock Mattresses were placed 50% into the channel using a dive team to prevent bed scour over the gas pipe.

Below is a reference from the client:

Gents,

Attached is one of the latest photos I took before demobilisation, which shows how well the rock mattresses and brushwood is accepting the silting and fill following some extremely high water over the past week.

I would also like to take this opportunity to congratulate your company in delivering a very good project under such difficult climatic conditions.

Your management support, when required, your professional and knowledgeable input, and your dedicated on-site team led by Rhodri Henry, ensured a successful outcome for the project. I enjoyed working with you immensely as part of the team ethic approach.

I hope we will have the opportunity to work together again.

Best regards,

Mike Wood, Project Supervisor, Wales & West Utilities.

Details

Name: River Tywi Pipeline Protection
Client: Wales & West Utilities
Location: Carmarthen
Category: Intertidal Rivers, Rivers & Water Courses

Case Study