Burst strategic trunk main cuts supply to up to 10,000 Isle of Wight properties

Southern Water reported a major burst on a strategic trunk main in Blackwater, near the River Medina, which affected water supply to customers in Shanklin, Wroxall, Newchurch, Alverstone and Rookley on the Isle of Wight. In an update at 4pm on Thursday 27 March 2025, the company said the burst had impacted its Cooks Castle reservoir and that up to 10,000 properties were affected¹. By 8am on Friday 28 March, it said the repair had been completed in the early hours and that most customers had already had water restored overnight¹.

At 4pm on 27 March, Southern Water said tankers injecting water directly into the network were restoring supply to around half of the affected addresses, and that restoring the remainder could take until late into the evening because the repair was complex¹. At 9pm the company said excavation around the main was almost complete, that water had been taken from other parts of the network to start refilling the reservoir, and that it anticipated all affected properties would see their water return overnight¹.

Bottled water stations were opened for customers without supply. The first, at Amazon World Zoo on Watery Lane, Newchurch, Sandown, PO36 0LX, opened on the afternoon of 27 March and was due to stay open until 11pm that evening¹. A second opened at Morrisons Car Park, Newport Rd, Sandown, PO36 9PA, and both were listed as reopening at 8am on 28 March¹. At 8am on 28 March the company listed a station at the Co-Op, Landguard Road, Shanklin, PO37 7JR, for pedestrian traffic only¹. At 1pm that day it said both sites had been very quiet since opening and would close at 2pm, with reactive plans in place to reopen bottled water stations if needed¹.

Southern Water said it continued to deliver bottled water throughout the night to all 3,000 customers on its Priority Services Register in the area, and that about 3,000 deliveries were completed overnight, with a second and final round due to be completed by the afternoon of 28 March¹. The company gave a helpline for vulnerable customers needing bottled water as a priority, or for other queries about the interruption: 0330 303 0368¹.

On discoloured water after a supply interruption, Southern Water said this is normal and usually temporary. It said cloudy white water may be trapped air and can be left in a glass for a few minutes to see if it clears; brown or black water should be run for a few minutes, and if that does not work the tap should be turned off, left for 20 minutes and tried again. It said it is fine to use water as normal once it runs clear¹.

Why it matters for households

The interruption affected households in five named areas of the Isle of Wight, with up to 10,000 properties involved at its height. Supply was being restored in stages from the afternoon of 27 March, with the company anticipating all affected properties would see water return overnight, and any remaining properties back in supply later on the morning of 28 March¹. Households on the Priority Services Register, which Southern Water describes as support for people who may need extra help because of age, illness, disability or other circumstances, received bottled water deliveries overnight and a second delivery the following day¹. The company's published guidance covers what to expect when water returns, including temporary discolouration, and its helpline remains the route it gives for vulnerable customers and medical needs¹.

What happens next

Southern Water said its two bottled water stations would close at 2pm on 28 March, with plans in place to reopen them if needed, and that the second round of Priority Services Register deliveries should be completed that afternoon¹. The company said it would keep its website and social media updated¹. No further timetable for the incident has been reported.

Households can find practical steps in the guide to a supply interruption kit, information on how water companies respond to a major incident, and guidance on how to report no water or a burst pipe.