IT IS 42 degrees Celsius, there has not been any rain for weeks, and the risk of a wildfire is severe. In this dusty corner of southeastern Spain in August, the grass has turned yellow, and fields of cereals are perishing in the heat after months without rain. Walking along the road, it feels as if your skin is burning in the heat.
But on the outskirts of Ribarroja, a small town near Valencia, there is an unusual line of defense against a possible blaze. Looming above the trees near the edge of the town is a series of huge green towers that resemble streetlights. They act as mammoth water sprinklers, showering the trees and bamboo plants below with recycled water to reduce the chance of fire. They’re supplied with recycled water from the nearby houses in Ribarroja and neighboring Paterna.
This is the biggest defense system against wildfires in Europe, consisting of 40 towers that encircle the towns, the largest standing 24 meters tall. Known as the Guardian project, it protects urban areas surrounded by trees or other vegetation from the devastating effects of a wildfire by hydrating the plant life, creating a natural barrier. With climate change increasing the threat of wildfires across the continent, Guardian-style defenses could become a fixture of high-risk parts of Europe in the future.
Watering vegetation can delay the spread of a blaze because plants containing greater amounts of moisture require more of a wildfire’s energy. Other factors affect the spread of a wildfire—wind speed is crucial, for example—but generally the drier the vegetation, the more quickly a fire will consume the landscape.
“Water eats up some of the energy of a fire,” says Ferrán Dalmau, CEO of forest fire consultancy Medi XXI GSA, which developed the Guardian system. “If a plant is better hydrated, then it will slow down the fire.” But Dalmau warns that the system will not put a fire out. Guardian can slow and help control a blaze, but it doesn’t replace the need for fire services to intervene.