Medellín’s Green Corridors: 30 Corridors That Cooled the City by up to 2°C
Medellín built 30 green corridors between 2016 and 2019, planting 2.5 million plants and 880,000 trees, and won the 2019 Ashden Award in the nature-based cooling category for it (Alcaldía de Medellín; Alcaldía de Medellín).
The project is genuinely one of the better-documented urban climate adaptations anywhere. It is also routinely described with inflated numbers, so the figures below are the ones that carry a source.
Verified figures
| Figure | Value | Source |
|---|---|---|
| Green corridors | 30, built 2016–2019 | Alcaldía de Medellín |
| Split | 18 along roads, 12 along stream setbacks | Alcaldía de Medellín |
| Also counted as | 17 road corridors, 12 streams, 3 tutelary hills (Nutibara, El Volador, La Asomadera) | Alcaldía de Medellín |
| Planted | 2.5 million plants, 880,000 trees | El Colombiano |
| Earlier phase | 120,000 plants, 12,500 trees on roads and parks | El Colombiano |
| Species detail | 8,300 trees and palms across 72 species, 353,765 shrubs | El Colombiano |
| Ambient temperature | reduced by up to 2°C | Semana |
| Initial investment | US$16.3 million | El Colombiano |
| Award | 2019 Ashden Award, nature-based cooling | Alcaldía de Medellín |
Note on the temperature figure. The widely quoted number is a reduction of up to 2°C in ambient air temperature — not an average, and not the same as the larger surface-temperature reductions measured on the treated ground itself. The two get conflated constantly. Ambient air is the harder and more meaningful measure.
What the corridors actually are
The common description — “30 restored waterways” — is wrong in an important way. The majority of the corridors follow roads, not streams. The 30 comprise 18 routes along major thoroughfares and 12 along stream setbacks, with the city’s own environmental secretariat also counting three cerros tutelares — Nutibara, El Volador and La Asomadera — within the network.
That matters because the road corridors are where the heat problem is. Replacing hard surfaces with soft, planted ground retains humidity, cuts the urban heat island effect and captures particulate matter, and roads are the hard surfaces generating the heat (Semana).
The stream corridors worth walking
La Iguaná and Santa Elena are described by the city as the strongest biotic corridors in Medellín — the two that do the most ecological connection work, linking the valley floor to the hills on either side.
La Presidenta is one of the stream corridors and the easiest to reach for most visitors: it runs through El Poblado, on the eastern side, as a linear park with walking paths. It is a short walk from Provenza and the best place to see what a restored quebrada corridor looks like without leaving the tourist part of the city.
The mechanism
Three things do the cooling:
- Evapotranspiration. Planted ground and tree canopy release water vapour, which cools the surrounding air.
- Surface replacement. Swapping hard floors for soft ones conserves humidity and stops the ground storing and re-radiating heat — the core of the urban heat island effect.
- Connectivity. Corridors along the valley’s natural drainage lines link fragmented green space, which is what makes them work as habitat rather than as decoration.
Researchers at the Universidad Nacional de Colombia’s Medellín campus produced the first map of the city’s green corridors using Landsat 8 satellite data, applying landscape-ecology techniques to identify routes that minimise the physiological and ecological cost of species moving between points (Universidad Nacional).
Visiting
The corridors are public streets and parks, not a ticketed attraction — there is no entry fee, no official tour, and no booking required.
- La Presidenta, El Poblado — the most accessible linear park, walkable from Provenza.
- La Iguaná and Santa Elena — the two most ecologically significant corridors.
- Cerro Nutibara, Cerro El Volador and La Asomadera — the three tutelary hills counted in the network, all climbable, all with views over the valley.
Go in the morning, wear shoes with grip, and treat them as city parks: they run through ordinary neighbourhoods rather than a reserve.
A note on this guide
This page was rebuilt in September 2026. An earlier version carried a large number of specific claims — an official mobile app, interpretation centres, kilometres of dedicated cycle path, property-value uplifts, job counts, a list of international awards, a count of cities replicating the model, and an IoT sensor network — none of which could be sourced. They were removed rather than left standing. The Ashden Award year and the road/stream split were corrected, and three placeholder figures that had never been filled in were deleted.