The McAlister stormwater pump station plays a key role in draining stormwater from the Whakatāne urban area.
There are currently four separate pump stations that discharge stormwater into the Whakatāne river from the Apanui catchment. The McAlister pump station accounts for 70% of the total catchment pumping capacity.
The Apanui catchment is approximately 2.5 square kilometres. It extends from the Landing Road Bridge in the west to Domain Road in the south, and includes the CBD area and the hill suburbs around Hillcrest Road and Waiewe Street. This area represents approximately one-third of the entire Whakatāne urban area.
Stormwater pumping is critical in this catchment, because there are significant areas where the ground level is at or below the high tide level.
This pump station can currently discharge just over 3,000 litres of stormwater per second. The current project will increase that pumping capacity to almost 6,000 litres per second, which will increase the drainage from the catchment by about 65%.
This is the station’s first major upgrade since it was built in 1965.
During a heavy rainfall event (with a likelihood of occuring approximately once in 10 years), the catchment generates around 19,000 litres per second of run off. At that rate of run off, it would take less than three minutes to fill one Olympic-sized swimming pool.
The upgrade involves the following key features:
- Significant structural modifications and widening of the inlet screen from 7 metres to 12 metres
- Replacement of the three existing pumps with three new, high-efficiency submersible pumps
- Complete replacement and upgrade of the electrical and control systems
- Installation of a 3 metre wide by 1 metre high box culvert that will be used to discharge stormwater when the river level allows
This project will play a key role in reducing the risk of flooding in the Apanui catchment. Your patience during the construction period is appreciated.