The River Hamble Harbour Board has campaigned for National Highways to put in measures that would keep – for example – an oil spill out of the river underneath the bridge.
Now National Highways has put in narrow lanes on that stretch of the motorway – between Junction 8 and Junction 9 – for the rest of the month for work. Previously it said work would go ahead but may not have been completed until 2025.
A statement says: ‘We’ll soon be carrying out work on the M27 Hamble bridge to help reduce any pollution from the road surface being washed into local waterways. This work will comprise of some preparation work, which will include drainage and waterproofing to the bridge.
‘To do this safely, we’ll be temporarily putting narrow lanes back in between junction 8 and 9 on both sides of the M27 from 9pm on May 7 until 6am on May 30. There will also be a reduced speed limit of 50mph through the narrow lanes. We’ll be working day and night to get this work completed as quickly as we can, and there will be over night full closures in place to provide safe working areas for the team.
‘We’ll be sure to monitor traffic flows during this time. We apologise in advance as the work may be noisy at times, but we’ll do our best to minimise this.’
This work is separate to the smart motorway changes.
Cllr Sean Woodward, the chairman of Hampshire County Council’s River Hamble Harbour Board, said: ‘I have written a number of letters to National Highways asking as a matter of urgency for interceptors to be provided to stop any motorway spills on the M27 Hamble bridge draining straight into the river.
‘The effect on the ecosystem from a large diesel spill, milk spill or similar could be devastating so this work is really important.’