Birdlip is a small Cotswold village with a modest residential community, a school, a public house, and a handful of local businesses. Central to the village’s infrastructure, the Birdlip Distribution Service Reservoir (DSR), constructed in 1971 with a total capacity of 8,460 m³, provides essential potable water to the surrounding area.
The reservoir comprises monolithic reinforced concrete walls, floor, and roof slab, divided into two compartments by a full-height partition wall. Predominantly above ground level and backfilled with steep embankments, the asset requires meticulous maintenance to preserve water quality and structural integrity.
In June 2024, CRL was appointed by Severn Trent as Principal Contractor to carry out a comprehensive refurbishment, addressing both internal and external deterioration and ensuring the reservoir continues to meet modern standards and operational requirements.
Services Undertaken
- Removal of abandoned sample line and pump from outlet pipe
- Internal surface cleaning, de-scaling, and preparation of valves and pipework
- Removal of old bitumen paint from internal joints
- Application of Masterseal 933 over-banding to wall and floor joints
- Spark testing to verify joint integrity
- High-pressure jetting and wire brushing of pipework
- Installation of compliant internal ladder and handrailing around washout sump
- Disinfection and flood testing of internal compartments
- Roof clearance, excavation, and preparation of roof-to-wall joints
- Application of Proofex bonded membrane and elastomeric over-banding
- Re-bedding of roof hatches
- Installation of geocomposite drainage layer and 150mm river-washed gravel
- Upgrades to drainage including French drains, soakaways, and scour pipe flap valve
for every job
The refurbishment of Birdlip Reservoir involved a detailed, multi-stage programme of works designed to extend the asset’s service life and ensure compliance with potable water standards. Internally, the project began with the removal of the abandoned sample line and pump from the outlet pipe. Following this, all surfaces underwent thorough cleaning, including de-scaling the cross-connection valve, cast iron inlet, outlet, and washout areas. The removal of old bitumen paint from internal joints allowed the application of an over-banding system using Masterseal 933 to all wall and floor joints, ensuring a watertight seal. Spark testing verified the quality of the repair works. Pipework received high-pressure jetting and wire brushing, while internal safety was enhanced with a new compliant ladder and handrailing around the washout sump. Completion of internal works included disinfection and flood testing to confirm readiness for potable water.
Externally, the roof was cleared of topsoil, vegetation, and gravel, and the roof-to-wall joint exposed for over-banding with Masterseal 933. A new bonded Proofex membrane was applied, complemented by an elastomeric over-banding system to seal roof cracks. All hatches were re-bedded, followed by installation of a geocomposite drainage layer and 150mm of river-washed gravel. Drainage upgrades included French drains, soakaways, and a flap valve at the scour pipe outlet. Every step combined specialist concrete repair techniques, modern waterproofing systems, and meticulous quality assurance to restore the reservoir’s full operational functionality, structural integrity, and compliance with Severn Trent Water’s standards.
"The CRL team has done an incredible job on the DSR! It’s been completely transformed and looks fantastic. What stands out even more is their thoughtfulness and consideration for the community throughout the process. Their dedication to both quality and community has made this project a resounding success."
A Community Stakeholder
Long-term preservation measures at Birdlip Reservoir were designed to maximise durability and minimise maintenance. Over-banding of joints, high-quality membrane systems, and elastomeric sealants protect against water ingress and concrete carbonation, safeguarding the reinforced concrete structure.
Roof and perimeter drainage improvements, including geocomposite layers and French drains, mitigate surface water retention, reducing structural stress and potential corrosion. Safety upgrades, such as compliant ladders and handrailing, improve operator access and minimise risk.
These interventions collectively enhance the reservoir’s resilience, ensuring a reliable potable water supply, extending the service life of the asset, and reducing the need for frequent maintenance, thereby supporting effective asset management in the UK water sector.
the repair
