OG13 includes all works intended to secure natural land and environmental areas—slopes, rivers, forests—using ecological and environmentally compatible methods.
Declaratory (official definition):
It covers the construction, maintenance, or rehabilitation of point‑specific and widespread works necessary for land protection and for restoring compatibility between “sustainable development” and ecosystems. It includes all works related to botanical and zoological activities.
Examples include naturalistic, botanical, and ecological restoration; soil recovery in quarries and peatlands; restoration of hydrographic basins; mitigation of hydrogeological instability through planting; works for slope stability; reforestation; agricultural land improvement; and revegetation of roadside, railway, quarry, and landfill embankments.
