The problem
Two of four clarifiers had failed, the reservoir lost an estimated fifth of its water through cracks, and pumps sized for a 1980s forecast ran at poor efficiency. Newer estates on the edge of town went days without pressure.
The constraint
The water corporation, an example client, would not accept any planned outage. Every stage had to keep water flowing to the town.
The design
We placed new clarifiers on spare land beside the old ones, linked by temporary pipework. The reservoir was divided with a new wall so one half could be relined while the other stayed in service. New pumps were sized from six months of metered demand.
The network
Nine kilometres of ductile iron mains were laid mostly at night. Each length was pressure tested before connection, and every joint record signed by our resident engineer.
The result
Output is up by about 40 per cent, power use per megalitre is down, and the leak from the reservoir has stopped. The operator was trained on the new plant for six weeks before handover.
