Study of the agroforestry system of Alder (Alnus glutinosa) and Coffee (Coffea arabica) in Cundinamarca - Colombia, for water regulation. Total precipitation, internal precipitation, stemflow and runoff were measured over 10 months. Four replicates were used for plots with: coffee, coffee-alder, and managed pasture. Evapotranspiration was calculated. Basic statistics parameters, as well as Shapiro-Wilk and Monte Carlo tests with 1000 trials were employed. Results indicate that alder and coffee regulate 46%, while coffee alone 33% and pasture 21%. For the measured variables, alder and coffee had: internal precipitation 62.9%, stemflow 2.15%, interception 32%, runoff 52.4%, and infiltration 26.6%. Coffee had internal precipitation 70.7%, stemflow 1.6%, interception 27.7%, runoff 57.5%, and infiltration 11%. Finally, pasture had runoff 69.6% and infiltration 18.7%.