Elements of rocky landscape in the "Gorges (small canyon) of the Ciron" downstream from the "bridge of the Trave" in Préchac (Gironde, France). several kilometers of the river are constantly almost completely under a canopy, in a gallery forest, and sometimes in a small canyon. These conditions maintain cooler water, and environment and microclimate significantly cooler than average weather in the region. In late winter, some trees across the river following the recent gales and floods, but will be partially cut to allow the passage canoes while preserving natural jams essential for GES (Good ecological status) of the stream.