The Alder (Alnus glutinosa) and Coffee (Coffea arábiga) agroforestry system was studied in Cundinamarca Colombia, for water regulation. Total precipitation, internal precipitation, stem runoff and runoff were measured in 10 months. Four repetitions were used for plots with: coffee, coffee - alder and managed pastures. Evapotranspiration was calculated. Basic statistics parameters and Shapiro Wilk and Monte Carlo test with 1000 tests. Results indicate that alder and coffee regulate
46%, while only coffee 33% and grass 21%. The variables measured, alder and brown: internal precipitation 62.9%, stem runoff 2.15%, interception 32%, runoff 52.4% and infiltration 26.6%. The coffee internal precipitation 70.7%, stem runoff 1.6%, interception 27.7%, runoff 57.5% and infiltration 11%. Finally, pastures runoff 69.6% and infiltration 18.7%.
