Project Overview

This ECI scheme was delivered under the Welsh Water AMA Framework, and involved the provision of a new potable water service reservoir together with connecting infrastructure to the existing trunk main system.  

The innovative service reservoir has a minimum operational volume of 24.3Ml. It comprises reinforced concrete covered tanks to provide security and exclude potential contamination.  The tanks and covers were constructed of reinforced concrete. The tanks were set partly into the earth embankments raised around the walls for protective and aesthetic purposes. 

Separate 600mm diameter pipelines of circa 1,550m in length were provided for the inlet and outlet connections to the trunk main system. Connections were made in the A470 and agricultural land. 

During the ECI phase we carried out a detailed analysis of the scheme and through a number of workshops involving our client and key suppliers we developed an integrated solution for the methodology, planning and programming of the works. 

We developed, designed, manufactured, tested and successfully utilised a gantry system for the erection of formwork to the reservoir walls. This reduced the programme period by 6 weeks bringing substantial savings in our target cost by maximising working areas, and providing continuity of work. It minimised the need for craneage, providing significant cost savings, and reduced programme risk as works could progress in higher wind speeds. Risk due to winter working was also reduced as the shutters were insulated and a canopy could be utilised over the gantry frame to enable use of heaters to keep the area warm to assist placing of concrete and improving curing times. Due to the ease of handling and repetitive nature of the system, formwork outputs were also improved, reducing costs.

Project Gallery


Costain/Dwr Cymru Welsh Water


Glan Conwy

Project Value


Contract Period

97 weeks