his release includes the Python scripts, model results, and supporting datasets used to evaluate water age dynamics and contamination risk zones in Terminos Lagoon, southeastern Mexico. The hydrodynamic simulations were performed using Delft3D, and all post-processing and analyses were implemented in Python. This version supports the manuscript: Assessing Contamination Risk Zones with Water Age Modeling in Terminos Lagoon, Southeastern Coastal Mexico (Submitted) Main components: Scripts for water age calculation using model outputs. Evaluation of salinity and temperature model performance against field observations. Interannual flow analysis for the Candelaria and Palizada Rivers based on official CONAGUA data. Derived data products for water age (in days) across key lagoon zones. This repository aims to provide a reproducible workflow for coastal hydrodynamic and water quality analysis in tropical estuarine systems.