Walters have completed a 9 week refurbishment contract for our client, National Resources Wales, of Disserth Gauging Station near Llandrindod Wells in Mid Wales. We were tasked under NEC 4 Opt B contract for the temporary and permanent works across the scheme.
A structural survey of the site carried out by National Resources Wales earlier this year highlighted concerns regarding the structural integrity of the weir and the possibility of downstream scour issues. As principal contractor we carried out all of the remedial works required to extend the asset design life and ensure accuracy of flow gauging. Fish baffles and eel tiles were also installed to aid in upstream fish and eel migration.
Walters covered all of the physical works as follows:
- repair of the weir by removing unsound concrete and replacing with specialist, spray applied concrete
- removing the existing reno mattresses both upstream and downstream of the weir and replacing with rock armour
- Installation of fish baffles and eel tiles
- Improvement to the access track including new drainage and recycled plastic kerbs
- Construction of new cast in-situ concrete steps for access into the river
- minor additional works including fence replacement, removing existing concrete steps, and installing ducts and a column for telemetry equipment
We encountered a few challenges during the project as the River Ithon, which flows through the site, is designated as a Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC). In addition, our team had to protect a bat roost housed in the existing gauging station on site. A bat licence was issued for the project which imposed a number of restrictions in terms of working hours and methods of work. As an additional measure, acoustic barriers were erected around the perimeter of the roost for the duration of the scheme.