Tens of thousands of homes were left without water as a result of the burst on May 2, with more than 30,000 customers finally regaining their supply by May 7.
Bottled water stations were set up around town with road tailbacks as residents queued to get emergency water.
Following the outage, Southern Water announced it was setting up a £1m goodwill fund, which would include £120,000 for local festivals and events, £500,000 for community projects, and £380,000 to support businesses.
But the company sparked anger and dismay after it said households in Hastings and St Leonards, who lost their water supply due to the major leak caused by a burst pipe earlier this month would not be compensated.
Southern Water said the nature of the burst, coupled with the provision of alternative sources of water provided meant that the incident did not qualify for payment of compensation to households, under regulations and guidance set by the regulator, Ofwat.
Hastings and Rye MP Sally-Ann Hart said: “Several constituents contacted me about a planning application made by Southern Water in 2007 to replace the 12km section of ‘outworn’ raw water pipe from Darwell Reservoir to Beauport Water Supply Works.
“I am grateful to them for highlighting this with me, and I was able to draw this to the attention of Defra minister Robbie Moore and the CEO of Southern Water in my post-leak meetings with them.
“I have secured a commitment from Southern Water to replace the outworn 12km pipe with a dual system as a priority. A new planning application, landowner consents and environment impact reports amongst other planning requirements will need to be secured, and as we know, this will all take some time.”
A spokesperson for Southern Water said: “Replacing strategic mains is a key focus of our plans for the next investment period from 2025–30; we want to target these potential points of failure on our network so areas like Hastings don’t suffer outages of this scale in the future.
“Our £7.8bn draft business plan for 2025-2030 includes provision to increase our maintenance activities and in turn increase the rate of mains renewal. Rest assured this is part of our plan moving forward.”