Sutton & East Surrey Water Co (SESW) provide water (but NOT sewerage) services to a large swathe of West Purley, Kenley, Coulsdon etc. They're currently upgrading the water mains all round the area, and they're about to start on a major project to upgrade a large water main that runs under the A22 Godstone Road from the railway bridge southwards.
The main works will take place during the summer when schools are closed and traffic is much lighter, but to prepare for this, they're drilling three exploratory boreholes during the nights of Jan 27, 28 & 29 (Friday, Saturday, Sunday) and the road will be closed each evening 9:00pm - 5:00am.
Diversions signs will be posted, but for HGVs, it's a VERY long detour - they recommend using the A23 and A25! Full details are provided on the SESW website at:
During the hours of closure, the 412 will terminate in both directions in Purley station platform 6 car park but it's not clear what will happen to the 407 or 434.