Old Adelaide was shocked when unknown young planner Stephen Yarwood came from nowhere to win the Lord Mayoral race in 2010.

Then, it was dismayed as he went about actually changing things – and being so damned enthusiastic as he did so.

On Saturday, a business-backed candidate ousted him, thanks mostly to the preferences of a cashed-up member of the North Adelaide establishment whose policy platform was so reactionary it read like parody.

Yarwood was far from perfect, and InDaily has held him to account as rigorously as any. We questioned his trip to Texas to present the “key to the city” to Lance Armstrong; we revealed his embarrassingly large Telstra bill; we provided sceptical scrutiny of a range of council programs including free city wifi, moves against the homeless in the parklands and plenty more.

We reported on his administration’s many mistakes, with the Central Market management debacle and problems with the Adelaide Oval parking regime  high on the list.

What we haven’t done is participate in unsophisticated campaigns against change: we attempted to provide balance and facts to the mind-numbing “cars versus bikes” debate; we questioned the petty reactions against the colour of the Mall pavers; we rolled our eyes at empty cynicism about pop-ups.

Yarwood could be naive in his relationships with the media and as a politician, and his many enemies on the council were happy to hang him out to dry on unpopular issues, such as changes to the city’s roads and parking regimes.

He became the sole figure of blame for anyone stuck in traffic – as if one small section of bike lane had caused the city to gridlock (rather than the increasing numbers of people actually driving cars – a balance he attempted to address).

Attempts to paint him as a creature of Labor show no understanding of either Yarwood or the ALP.

He was fiercely independent to the point of political isolation, and this flaw might have led to his downfall.

He wanted to be re-elected in his own right, and his campaign involved a simple but taxing door-knocking campaign. He had no posters and, despite his reputation as a tech-head, his social media presence wasn’t particularly large. He refused to do preference deals, perhaps figuring that all of the other candidates aligned against him wouldn’t play ball anyway.

On Saturday he became a rare one-term mayor – but this electoral failure shouldn’t mask the fact that, unlike so many mayors before him, he left the post with the city a changed place; a place in better shape than when he arrived.

His legacy won’t be easily erased, because its impact went beyond the borders of the city centre, and his replacement Martin Haese is not quite of the staid ilk of former mayors (although much of his policy agenda is yet to be revealed).

Here are Yarwood’s three most important contributions.

He made us think differently about transport

In the absence of leadership on transport policy at the State Government level, Yarwood was a visionary – at least for a time.

As a self-confessed urban design policy wonk, he recognised what the planners of every major city in the world had seen before him – that successful cities are primarily places for people.

The council joined with Integrated Design Commissioner Tim Horton (who left SA earlier this year), to commission a major report by Gehl Architects on the city’s public spaces and public life.

While the State Government was steadfastly refusing to develop a transport strategy, Yarwood championed the Gehl report, which envisioned a more people-friendly city, with new tram routes, revitalised laneways, and a streetscape less hostile to cyclists and pedestrians.

The ensuing debate was one of several factors that caused the State Government to do an abrupt about-face and produce an integrated transport plan of its own.

The much-criticised Frome Street bikeway was Yarwood’s High Noon moment. As councillors went to jelly around him in response to public and media criticism, Yarwood was left as a lone voice defending an infrastructure concept which is commonplace elsewhere.

Yarwood changed his public rhetoric in the face of constant sniping, moving away from defending the need for multiple integrated forms of transport to take pressure off the roads system, to simply pushing the health benefits of cycling.

As the CEO of Cycle SA, Christian Haag, noted last week, Adelaide is one of the last Australian cities left to build decent cycling infrastructure. In every other city where this has occurred, conservative forces have initially fought tooth and nail against it.

Nevertheless, at least we now have some understanding of the issues and tensions – there’s no going back to square one now.

He helped re-energise the city

In 2010 when Yarwood entered Town Hall, Adelaide’s city was stuck in a rut, famously recruited as a film stand-in for 1970s Perth.

He had the advantage of coming to power just before a changing of the guard at State level.

New Premier Jay Weatherill also wanted to re-energise the city and, with a like mind (at least on this point) in Town Hall, the two administrations entered a rare period of cooperation.

Yarwood’s championing of food trucks and the Splash Adelaide program, which filled unloved corners of the city with interesting happenings, worked seamlessly with the Government’s licensing reforms, which freed young entrepreneurs from red tape to spark an explosion in small bars and restaurants across the city.

The Government’s massive investment around the Riverbank gave the council the confidence to begin decades-overdue transformations of Victoria Square and Rundle Mall.

Yarwood found the dysfunctional wasteland of Victoria Square to be particularly galling. Whatever you think about the design solution in Vic Square, Yarwood’s administration finally crashed through years of inaction and handwringing to create a new and usable place.

People actually go there now and do things – in Adelaide, that’s a big win.

The nerdy Lord Mayor pushed the idea that technology was crucial to a modern city: a free wifi network was negotiated and installed across the CBD; a smart, tech-heavy, new library was built in a lane off Rundle Mall.

People could see and feel that the city was changing. Young people, in particular, imagined a new kind of city living and working that hadn’t occurred to them before.

Adelaide seemed almost cool, for the first time since Dunstan.

He showed us we could change

We didn’t even talk about “Old Adelaide” and “New Adelaide” until Yarwood came to power.

A whole generation of Adelaideans had lost any faith that the city could change for the better or, for that matter, in any way at all.

Yet Yarwood managed to enthuse people from across Adelaide, not just those who live in the CBD, with his imagination about the city’s possibilities and his willingness to be the public voice of reform (a sort of bravery that probably cost him the Lord Mayorship).

And this leads me to his greatest contribution to the city.

While his civic opponents talk in dull and earnest tones about the council’s budget lines, debt to revenue proportions, the removal of a slip lane in this street or that, and the hue and slip rates of various pavers, a large swathe of the population will remember Yarwood as a Lord Mayor who helped them to believe again in Adelaide and its future.

For this, at least, New Adelaide will thank him.

Old Adelaide may be celebrating today, but their world has been changed for good.

David Washington is editor of InDaily.