In arid and semi-arid regions a progressive decline of water resources will impact all socio-ecological and economic dynamics. The semi-arid region of north-central Chile has not been exempt from these climatic scenarios. The Choapa River flow records show an increase in the variability of the flow rates from 1985 and a constant decline in total discharge from 2002 to date. So the aim of this talk will be to present a 168 year hydro-climatic reconstruction of the Choapa River using Kagenekia angustifolia trees.