Upgrades to Moutoa Floodgates complete

Horizons Regional Council’s Moutoa Floodgates, which provide flood resilience to 280 km² of land in the lower Manawatū River area, have been upgraded.

Horizons Regional Council group manager catchment operations Dr Jon Roygard says an investigation into the condition of the gates revealed work was needed.
 
“Our investigation showed us the gates were showing their age. Aside from routine maintenance, no significant upgrade work had been done on the gates since construction in 1962” says Dr Roygard.
 
“Being more than 60 years old, many of the components were showing signs of ageing.”
 
In order to continue providing the same level of service, a number of upgrades were identified for the gates, says Dr Roygard.
 
“Communities in the Horowhenua District rely on these gates to work as they should when they’re needed. It’s our responsibility as Horizons to maintain the condition of the gates so they continue to serve their intended purpose,” he says.
 
“The gates are part of a wider network of stopbanks, pumpstations and smaller floodgates which provide flood resilience to a significant area, including many homes and productive farmland, surrounding the lower reaches of the Manawatū River.
 
“We worked with GHD engineers to complete an initial report identifying areas in need of work to bring the gates up to a modern design standard, so they keep working for decades to come.”
 
Horizons river management team leader projects Diandri van Zyl says a series of mechanical and electrical upgrades were identified as needed to achieve this goal.
 
“The old overhead electrical lines, which spanned across the gate piers themselves, were replaced with two H-structure power poles across the spillway area. This has made access to the concrete piers for maintenance and inspections much easier, and has also increased the resilience of power supply to the gate controls.
 
“In case of power failure, an automatic power switchover between the mains supply and a backup generator was installed in the control tower. A new motor control system, which controls the lifting and lowering of the gates, was also installed.
 
“Finally, the most complex and time-consuming portion of the upgrades was the replacement of the winch drum, gear boxes and sheaves which lift and lower the gates.”
 
Mrs van Zyl says Council awarded the contract to Seipp Construction.
 
“The contract included the custom fabrication of the replacement mechanical components for each of the nine gates. This presented a unique design, fabrication and engineering challenge for the contractors,” she says.
 
“They were motivated by the significance of this asset to our region’s communities, and worked with care to do things right.”
 
Dr Roygard says the upgrades were funded through a mix of central government funding and targeted rates.
 
“We were able to secure 75 percent of the $2.5 million total upgrade cost through Kānoa – Regional Economic Development & Investment Unit. A condition of this funding was being able to complete the work in a certain timeframe,” he says.
 
“Working with the right contractors and consultants meant we were able to make it happen, and deliver quality flood resilience outcomes for our communities effectively and efficiently.”
 
Learn more about the Moutoa Floodgates, including how they work and the upgrades, here.