Protecting against storms disrupting supply

Protecting against storms disrupting supply

Project Title: Construction of Malololelei Transmission Main Upgrade

One of the most significant problem areas has been disruptions to the transmission pipeline feeding water from the river intake to the treatment plant at Malololelei (located on Cross Island Road in the hills to the east above Apia urban district). Disruptions to the urban water supply were often caused by severe damage or breakage of the transmission pipeline during heavy rainfall periods or cyclones. Disruptions to the Malololelei network affected a population of 4,000 people, who would usually be without water until repairs to the transmission. During cyclones and heavy rainfall/flooding access to the transmission becames very difficult and was often dangerous which meants repairs could not be made until the strong river flows decreased. Residents were left without water for days. 

In 2016, SWA replaced and upgraded the most vulnerable 300 metre section of the transmission pipeline. As a result, during Cyclone Olaf and the heavy rain periods and storms that followed the transmission remained intact and the service remained uninterrupted.  More than 4,000 people have benefitted, no longer suffering the frequent losses of water supply that used to occur.

Another challenge that SWA often faces during storms and high rainfall periods is clogging of intakes and high turbidity (water discoloration) which often causes extensive interruptions to supply.  To minimise service disruption SWA has established inter-connectivity in most of its networks, which means in the event of disruption to one network, the neighboring network is extended to supply that area while the disrupted supply recovers.  It has meant that in recent years thousands of people have had their supply maintained after storms, which in the past would have caused major and lengthy disruptions.