Study region: The Middle Atlas Mountains in Morocco is a structurally complex karst where carbonate plateaus and major faults cut Liassic carbonates and Triassic evaporites, sustaining groundwater resources for adjacent semi-arid plains. Study focus: A multi-tracer approach to constrain regional flow architecture, recharge elevation, groundwater age, and the processes controlling mineralization across unconfined and confined karst compartments. We combined major-ion hydrochemistry with environmental isotopes (S2H, S18O, 3H, and 14C) from 60 springs and 8 surface water sites, the study quantifies recharge elevations, groundwater residence times, and the geochemical drivers of mineralization in both unconfined and confined aquifer compartments. New hydrological insights for the region: The study establishes the first massif-scale isotopic baseline, defining a new Local Meteoric Water Line (S2H = 7.99 S18O + 14.56) and a vertical S1 8O gradient of - 0.23 parts per thousand per 100 m, placing recharge altitudes between 700 m and 2490 m. Findings reveal a dual-flow system: fast-flowing conduit networks with modern water and confined compartments containing significantly older groundwater. Mineralization is primarily driven by subsurface Triassic evaporite dissolution. Furthermore, the Tizi N'Tretten fault zone is identified as a critical structural control facilitating vertical circulation and inter-basin flow, providing a vital framework for managing Mediterranean karst resources.