AdvertisementThe lower bowels of the Hidroituango hydroelectric dam, four hours outside of Medellín, Colombia, are generally reached through tunnels saturated with stale petrichor and air that grows thicker with every step downward. Tunnel walls shift from gray to mud-colored on the descent, and warm drops of water fall from the craggy roof. For eight months, these tunnels and chambers were the conduit for Colombia’s second largest river, the Cauca, and when I visited in October, the scars of the river’s visitation were evident in concave sections of the walls where eddies of water had...…AdvertisementThe lower bowels of the Hidroituango hydroelectric dam, four hours outside of Medellín, Colombia, are generally reached through tunnels saturated with stale petrichor and air that grows thicker with every step downward. Tunnel walls shift from gray to mud-colored on the descent, and warm drops of water fall from the craggy roof. For eight months, these tunnels and chambers were the conduit for Colombia’s second largest river, the Cauca, and when I visited in October, the scars of the river’s visitation were evident in concave sections of the walls where eddies of water had...WW…