Structure of the rainfall-discharge reservoir model. ET the potential evapotranspiration. E0, M0, C0 the initial water level in the Epikarst, Matrix and Conduit reservoirs respectively. Emin the minimum water level in the Epikarst reservoir. EThresholdC a threshold level for discharge to the conduit reservoir. QEM and QEC the discharge from the Epikarst reservoir to the Matrix and Conduit reservoirs. QMS and QCS the discharge from the Matrix and Conduit reservoirs to the Spring.