Project: Defence works against torrential rains in the town of Ojacastro (La Rioja) Activity: Environment Product: HYDROLOGICAL AND FOREST CORRECTION AND COMBATING EROSION Geographic data: Ojacastro, La Rioja, España Start date: August 2009 End date: June 2011 The Corravia Canyon has suffered floods by torrential rains, affecting the town of Ojacastro and the regional road. To control incidents of flooding in the future, corrective action has been undertaken along the bed of the canyon The core of this project to defend the town has been to build two squares for the runoff of storm water, in order to retain the large quantities of stone that tend to be washed away in the floods. These squares, made with stone masonry walls and riprap, are able to stop up to 4,700 m3 of material between the two. Other remedial techniques have consisted of building 15 dams with low environmental impact, for retaining sediments and stabilizing the riverbed. The dams are of various different types, ranging from the most traditional in stone masonry and concrete, to others with the most modern techniques of dynamic barriers made of steel ring nets, suitable for hard to reach locations.