It is like a spectacular magic trick – making a busy highway disappear while recovering a river whose biodiversity and flow was damaged by nine small dams built in the 1950s and polluted by runoff from the highway. Now bird songs have replaced the roar of traffic on the six-lane M30, the area’s fauna has recovered, and Madrid’s residents can visit a huge leisure and cultural spot,
Conservative politician Alberto Ruíz Gallardón pledged to bury the M30 ring road as part of his bid to become Madrid mayor in 2003. While many people were unhappy with the disruption as engineers tunnelled to reroute the M-30’s traffic deep underground, the €4 billion transformation was ahead of its time and has helped prepare Madrid for the effects of climate change.
The Madrid Rio project got underway in June 2008 and the last section was finally opened to the public in April 2015. Moving the M30 multilane highway underground, the biggest and most expensive part of the project, created a huge park area beside the river. The reengineered riverbank can collect extra water produced by 500 year flood events and the park will also help the city adapt to higher temperatures.

The dense tree cover will provide shade during periods of extreme heat, says José Luis Infanzón, Madrid’s general director for public spaces.”We have thermographic images that show how the tree-lined park acts as a corridor for cool air coming from the north. The up to 700,000 people that live in the immediate surroundings of the river can get relief here when temperatures rise.”
Not only has the Madrid Río riverside park become one of the city’s most popular spots, with pedestrians, joggers and cyclists sharing the verdant paths through the park’s 120 hectares, it has attracted wildlife, including wild boar making their way from the Monte del Pardo forest in the north to the Lineal Park in the south.
“For a city to evolve you have to be ready to question the things everyone thinks are unchangeable and be prepared to do the things no one ever thought possible,” José María Ortega, the city’s general coordinator for urban development, told Politico.
That included letting the river flow freely again by opening the urban dam gates, starting in 2016. “Leaving the dams open has meant going back to having a river that exists in winter and nearly vanishes in summer, but it’s also meant allowing nature to come back to its waters,” said Infanzón.
Mallards, herons and egrets built nests; migrating wagtails, kingfishers and cormorants stopped off en route to Africa. The river is now also home to foxes and even endangered otters not seen in the Spanish capital since the 1950s.

Ortega added that turning the river into a place where Madrileños can once again congregate was also helping heal a social division. For decades, the M-30 separated the city’s western working-class districts from central, more prosperous neighborhoods.
Throughout the length and breadth of Madrid Río, there are now 30 kilometres of cycle paths; 33 sports fields for skating, skateboarding, climbing, 7-a-side and 11-a-side football, futsal, padel tennis, tennis, basketball and BMX cycling; 17 children’s play areas; 3 fitness trails; 7 pétanque courts; 12 games tables; 3 cultural event platforms in the Puente del Rey and Matadero and an Interpretation Centre for the Manazares River.
There is a city beach comprising three aquatic areas in Arganzuela park, requested by children in the Madrid Rio Children and Young People’s Competition. In addition, 5,506 new benches, 63 drinking fountains, 84 bicycle racks with 637 spaces, as well as 8,528 lampposts have been installed. To facilitate crossing between districts on either riverbank, there are 33 walkways.
“This project is, in a lot of ways, one of unification,” Ortega said. “It’s allowed the city to reconcile with nature, stitching communities back together.” And as the fascinating Madrid No Frills post shows, the river has a lot of history.
Countries which are planning improvements to their current transportation infrastructure, such as Poland, Russia, the Czech Republic, Romania, Hungary, France and Italy, have visited the Calle 30 Project and many companies involved in it have recently been selected for infrastructure contracts in the UK and the US.
The M30 project was on display in the Urban Best Practices Area of the 2010 World Expo Madrid Pavilion in Shanghai. The theme of the Expo was “A Better City for a Better life” and Madrid’s M30 project was selected as a transferable best practice for display.
Sources:
How Madrid reclaimed its river. Politico, Jan. 3, 2023
Woolly mammoths and washerwomen: hidden histories of the Manzanares River. Madrid No Frills, Mar. 30, 2021
Madrid Rio Project. Urban Sustainability Exchange.
Cover image and the other photographs are from the USE case study of the Madrid Rio Project.