100,000 m3
reservoir capacity
Saggart Reservoir Project
The Saggart Reservoir Project seeks to increase the resilience and connectivity of the Greater Dublin Area’s water supply network. It allows for operational flexibility from various incoming supplies and facilitates future connectivity with the Eastern and Midlands Water Supply Project. We assisted our client Irish Water all the way from the preliminary design and options assessment, through planning and procurement and finally on to the construction stage.
This reinforced concrete reservoir has a capacity of 100million litres, with inlet and outlet valve houses and interconnecting pipework for flow management, along with a secondary chlorination plant. Ancillary works include drainage systems and a de-chlorination plant for the emergency reservoir overflow system which protects the River Camac. We also ensured a facility to connect solar arrays on the reservoir roof was included in our design. This will be capable of supplying power to the site, with a surplus to export in the future.
Key details
Project name: Saggart Reservoir Project
Client: Uisce Éireann
Location: Saggart, Co. Dublin, Ireland
Services provided:
- Feasibility and design reports
- Site investigations
- Detailed site surveys and condition assessment works
- Civil and MEICA design
- Hydraulic modelling
- Planning process
- Stakeholder engagement and strategy
- Procurement of advance works and main works
- Contract administration
- Site supervision
Challenge
The biggest challenge was enabling the client to maintain supplies with minimal disruption during the construction works. The completed reservoir structure has a large footprint to meet hydraulic design requirements and reduce the visual impact of the structure. This presented a planning challenge, requiring a solution that was environmentally sustainable within a restricted site, which was also on the flight path to Baldonnel Aerodrome. The main technical challenge was to make the best use of the lands available, providing the maximum storage capacity while maintaining supplies to the city. To reduce impact on the downstream network, we implemented live connections to existing tanks and pipelines using under pressure tees and line stop techniques.
High and medium voltage power supplies crossing the site had to be diverted under an advance contract, taking into consideration the local authority’s proposals for a link road and heritage trail in the future.
There were also a number of environmental challenges, including the management of runoff from the works, the provision of an emergency overflow system from the reservoir to the River Camac and the disposal/reuse of large volumes of surplus soil.
Solution
Over a series of workshops, we engaged with operators of the overall trunk supply network to the city to develop a viable solution. The outcome was a clear schedule of works, facilitating integration with the existing trunk network, while minimising disruption to customers.
Ahead of finalising the planning submission, stakeholder engagement was key to understanding and agreeing acceptable solutions for inclusion in the design. For example, the reservoir overflow system was designed to attenuate 10,000 m3 of overflow before discharging to the River Camac. This gave operational staff sufficient time to react to an overflow alarm. In addition, all overflow discharges to the river are de-chlorinated to protect aquatic life.
Statistics
130,000 m3
volume of material excavated
3,000 t
of reinforcement
2500 m
of ductile iron pipes
