Many of us walk over them each and every day without a second thought about what could be lurking beneath our feet.

And with hundreds of miles of drainage systems spanning across the entire city, it’s hard to imagine exactly what goes on in this dark and mysterious unknown realm.

But armed with a torch light and relying on the trusty guidance of the drainage pros at Streets Ahead, the new Cabinet member for Environment, Street Scene and Climate Change at Sheffield City Council, Councillor Mark Jones, has wasted no time in uncovering these rarely seen, hidden waterways – which serve an essential role in our city.

When water disappears down the grated drains, we rarely consider just what a long and complex process then takes place to ensure everything that ends up down under, is routed back to where it should be.

And with a Met Office study finding that extreme rainfall in the UK is now seven times more likely*, it’s a system that never has time to stagnate.

On the surface, there are thousands of cast iron gullies which provide an escape for the surface water that runs through our hilly streets.

Built by the Victorians over 100 years ago, the complex drainage system has adapted to the changing weather conditions and transforming street scene that is now maintained as part of the council’s Streets Ahead programme.

After just one month in post, the new Cabinet Member for Environment, Streetscene and Climate Change has already been down under to see the marvels of Sheffield’s underground waterways with his own eyes.

“It’s not exactly what I had in mind for my first month in post,” laughed Mark “But it’s only when you go down there that you realise what an impressive and important part of the city’s infrastructure this is.

“There’ so much more to see beneath the surface and, surprisingly, I didn’t come across any swamp monsters or ninja turtles!

“But whilst there’s lots to take in down there, it’s also apparent that’s there’s a continuous programme of work that goes on to keep the system clean, safe and flowing in the right direction.

“The team at Amey work around the clock, on behalf of the council, to clean, maintain and sometimes even widen the many gullies, manholes and culverts that provide a vital function for draining surface water from our streets.

“It’s certainly a challenging job and the operatives who maintain the drains need specialist Confined Space Training before they can even start the task at hand. It’s a really unique, yet intriguing environment where safety has to be a top priority for every move you make.”

One of the most spectacular culverts is the mighty Megatron, an enormous cathedral-like structure that is part of an enormous complex of Victorian storm drain tunnels carrying the River Sheaf and Porter Brook underneath the city.

Just like any other, The Megatron is subject to routine maintenance; most recently last year when it was repaired, repointed and re-painted by Streets Ahead in time for the first public tours, which were held as part of this year’s Sheffield Adventure Film Festival.

In addition to the work underground, above ground, Streets Ahead also ensure that low spots at road junctions and flooding hotspots are prioritised by their teams to help prevent surface flooding.

Since the start of the contract, around 3000 sub-standard gullies have been replaced with plans to replace a further 3000 before 2037. What’s more, over 100 schemes to improve drainage across the city have been undertaken in recent years.

Using specialist suction machines, the many gullies, which can be easily blocked by a range of items, are cleaned on an annual cycle.

Leaves from the city’s 36,000 street trees contribute to the accumulation of mulch in the drains during the autumn months, either slowing the rate of water flow or solidifying and blocking pipes completely.

But the dark and dank conditions are no deterrent for the specialist CCTV unit that is used by the teams to help diagnose hard to reach issues or problematic build-ups when they occur.

And of course, the oddest of things can be found down drains or in the culverts, as

Melissa Wise, Operations Director for Amey Streets Ahead explains:

“Some years ago, we were doing some work opposite the Hillsborough Stadium at Leppings Lane when one of our team saw what he thought might be a bomb in the river.

“The Army bomb squad came out and said they thought it might be a World War II bomb. But on further inspection it turned out to be nothing more than a brewery container!

“We get some random and unexpected calls to rescue items dropped down the drains, from sentimental things like wedding rings to everyday essentials like mobile phones.

“Literally it can be anything – we get all sorts ending up down there, whether purposely or not.”

But the journey doesn’t end there. After finding its way into the underground system, the water continues its journey through various culverts and underground pipes before eventually flowing into the River Don, to start its cycle once again.

To find out more about the Streets Ahead programme visit: www.sheffield.gov.uk/streetsahead

Click here to view the video of Cabinet member, Mark Jones, in The Megatron.