After the Skewen flood: Do we need to do more to deal with old mine workings and coal tips?
Video report by ITV Wales reporter Mike Griffiths
The devastating flooding in Skewen in January, caused by water from old mine workings, brought misery to people in the village.
Many won't be able to return to their homes for months to come.
The flood is thought to have been caused by an underground drainage route that became blocked. Over time, water backed up and filled a disused shaft under a road in the village.
Heavy rain form Storm Christoph added to the pressure and meant the water eventually broke out of the ground. The shaft itself subsequently collapsed, presenting a further problem.
As the cleanup continues, engineers from the Coal Authority will keep working in the village. Engineers will examine the extent of the damage and limit the potential risk for further collapse.
A system to manage the mine-water that continues to flow will also need to be built. The Coal Authority says this stage of the work will take six months to complete.
The landslide at the Tylorstown coal tip after Storm Dennis prompted scrutiny of the safety of a number of tips in Wales.
In January, First Minister Mark Drakeford told ITV Wales that the cost of a ten-year programme to study tips and carry out remediation work would cost an estimated £500-600m.
Problems caused by old mine workings, while rare, have required innovation solutions.
The closure of Taff Merthyr Colliery, near Treharris, in the early 1990s was carried out like many others at the time.
Buildings were flattened, the shafts filled, and pumps switched off.
Within two years, rust-coloured mine-water found its way out of the workings via the shafts and was beginning to contaminate the nearby river.
A system of lagoons and reed beds was put in place to naturally filter the water, addressing the problem before reaching the river.
Coal Authority Chief Executive Lisa Pinney stresses the Skewen flooding was caused by " a very, very unusual set of circumstances".
"Very specific things that have happened in the mine workings underneath. My team's been working round the clock to do everything we can to fix the problem, and build a new scheme to manage that water into the future.
"It's a really really rare situation. 52% of the population of south Wales live on the coal field. The vast majority will never experience any problems."
Is climate change and extreme weather posing new challenges?
In the coming months, the Welsh and UK Governments will continue to discuss new proposals for inspecting and maintaining coal tips.
But the events in Skewen, extraordinary as they are, inevitably raise the question over whether the scope of those proposals need to be wider.
Catch up with Sharp End on ITV Wales here.