FLOODING which shut down a key rail route in central Scotland has been blamed on a housing developer's failure to clear drainage ditches causing water to "cascade" onto the track.

Train services between Glasgow and Edinburgh ground to a halt twice last month when heavy rains caused the Winchburgh tunnel in West Lothian to fill with water.

Liam Sumpter, Route Director at Network Rail Scotland told a committee at Holyrood that the problem lay outwith his organisation's control, but assured MSPs that the problem would not occur again.

Water rose two feet above the track during the downpours at the start of August, overwhelming drains and Network rail's system of pumps - which were only installed in 2014.

READ MORE: Commuters warned of all-day rail disruption after Glasgow to Edinburgh shutdown​

Mr Sumpter said that Fire and Rescue services had cleared the floodwater using even stronger pumps, and that Network Rail was now looking at having these installed to cope with any future floods in the tunnel.

He said: "Winchburgh tunnel was redesigned as part of the Edinburgh to Glasgow improvement project four years ago, and as part of that the project team installed brand new drainage and installed pumps which, in the event there was any flooding in the tunnel, would remove the water quickly.

"We had extremely heavy rainfall in a very short period of time, which under normal circumstances we would expect the infrastructure to cope with there, given its relative newness.

"The problem with that first big flood was that a development company nearby the railway hadn't maintained the ditch that protected the railway as well as they should have done. As a result water cascaded onto the network far quicker than the drainage and the pumps could cope with."

The floodwater rose after almost two thirds of August's rainfall fell within three hours, completely overwhelming the infrastructure.

Trains were reduced to 5mph going through the tunnel this morning, with services between Glasgow Queen St and Edinburgh via Falkirk High and Cumbernauld affected.

READ MORE: Glasgow to Edinburgh trains cancelled over flooding​

Mr Sumpter said that water rose to two feet about the track, creating a safety hazard which made it impossible to drive trains through the tunnel.

The Herald:

Floodwater overwhelmed the track

A review of the network's ability to cope with heavy rainfall is now been carried out at Winchburgh and other tunnels across Scotland.

Mr Sumpter, who was responding to a question from Angus MacDonald, MSP, during a meeting of the Rural Economy and Connectivity Committee, added: "We are working with local landlords and the development company concerned to make sure they understand their responsibilities and we protect the railway from that ever happening again."

Alex Hynes, Managing Director of Scotland’s Railway, also took questions from the committee on what was being done to ensure lines remained open following heavy rainfall at the start of August which swept away parts of the West Highland railway.

The route, which connects Glasgow to the ports of Mallaig and Oban, was badly damaged by flooding after 80mm of rain fell in just a few hours at the start of August.

READ MORE: Staff 'almost at breaking point' over Scottish railways floods chaos​

Mr Hynes said that extra money was being made available to monitor the line, and that running a railway in Scotland was a "formidable task", with a network which was built in Victorian times when weather conditions were not as severe.

He was grilled by Labour MSP Colin Smyth over the Scotrail Alliance's projection that it will only achieve a passenger satisfaction level of 84 per cent this year, below the target of 87.5.

The Herald:

Mr Smyth said that this would mean the company would be in default of its agreement with the Scottish Government, and could be stripped of the franchise by Transport Scotland.

But Mr Hayes said that was unlikely, and that it was projected that customer satisfaction would breach 90 per cent by 2021.

He said: "The way the contract works is that it puts many thousands of obligations on Scotrail, the vast majority of which have been delivered.

"In extremis, failure to hit targets can be an event of default and Transport Scotland can issue a notice of termination if our performance fell below certain levels.

"But it's not going to, because we're investing £20 million of Abellio's money to improve performance and customer satisfaction, to give our customers increasingly the service they expect and deserve."