Our client asked for a pumping system, where they could harvest water from a stream during periods of high flow over the winter months, and pump the water to a storage dam.
Design requirements were
- The system needs to be automated
- Has to start/stop depending on water levels of the stream
- Water can only be harvested between fixed dates
- Maximum rate of take 100 litres/second
- Maximum total volume of 610,000 cubic metres
- Limited power available at proposed site
- 140m elevation change and 2km distance to storage dam
Our Solution
1. Install 2 x HDPE galleries under the stream, which feed into a concrete chamber.
2. The quantity of holes in the gallery and hole size are designed to get the water velocity down to prevent silt getting sucked into the chamber.
3. Size the holes in the galleries are small enough to prevent fish etc getting into the pipes
4. Install 2 x Rovatti vertical shaft pumps on the chamber, both with a duty of 55 litres per second @ 165 metres head
5. Install 2 x Greenpower 280kVA generators (one for each pump) in a purpose built shed
6. The pumps are both controlled by Variable speed drives to allow the rate of take to vary depending on stream flow level or demand from the irrigation system
7. Connect the pump system to a stream level monitoring system for full automation
8. We designed the system so the pumps can also pump directly to the irrigation system if the storage dam is full
9. The pumps will automatically start if one of the irrigators start
10. The pump system will not operate outside of the Consent parameters