Groundwater is the primary water source in arid and semi-arid regions in central Mexico, including the San Juan del Rio basin. While characterizing the contribution of deep groundwater flow into the shallow volcanic aquifer systems is often challenging, it is important in tectonically controlled settings. In this study, the occurrence and the rate of deep groundwater inflow was characterized using six different hydrologic models. By using a numerical groundwater model with particle tracking and comparing simulations with both hydraulic head and groundwater age data, the most likely hydrological scenario for the basin was selected. The findings indicate that a model which incorporates deep inflow, without significant hydraulic conductivity enhancement along faults, is the best representation of the system among the scenarios considered. This highlights the importance of incorporating groundwater age data, in addition to hydraulic head data, for accurately constraining flow regimes in aquifers, particularly those situated in tectonically active regions with regional circulation patterns. Les eaux souterraines constituent la principale source d'eau dans les r & eacute;gions arides et semi-arides du centre du Mexique, notamment dans le bassin de San Juan del Rio. Bien que la caract & eacute;risation de la contribution des & eacute;coulements souterrains profonds aux syst & egrave;mes aquif & egrave;res volcaniques peu profonds soit souvent complexe, elle est importante dans les environnements soumis & agrave; un contr & ocirc;le tectonique. Dans cette & eacute;tude, la pr & eacute;sence et le taux d'apport de flux d'eaux souterraines profondes ont & eacute;t & eacute; caract & eacute;ris & eacute;s & agrave; l'aide de six mod & egrave;les hydrologiques diff & eacute;rents. En utilisant un mod & egrave;le num & eacute;rique des eaux souterraines avec suivi des particules et en comparant les simulations avec les donn & eacute;es de charge hydraulique et d'& acirc;ge des eaux souterraines, le sc & eacute;nario hydrologique le plus probable pour le bassin a & eacute;t & eacute; s & eacute;lectionn & eacute;. Les r & eacute;sultats indiquent qu'un mod & egrave;le int & eacute;grant des apports de flux profonds, sans augmentation significative de la conductivit & eacute; hydraulique le long des failles, constitue la meilleure repr & eacute;sentation du syst & egrave;me parmi les sc & eacute;narios envisag & eacute;s. Cela souligne l'importance d'int & eacute;grer les donn & eacute;es d'& acirc;ge des eaux souterraines, en plus des donn & eacute;es de charge hydraulique, pour contraindre avec pr & eacute;cision les r & eacute;gimes d'& eacute;coulement dans les aquif & egrave;res, en particulier ceux situ & eacute;s dans des r & eacute;gions tectoniquement actives avec des sch & eacute;mas de circulation r & eacute;gionaux. El agua subterr & aacute;nea es la principal fuente de agua en las regiones & aacute;ridas y semi & aacute;ridas del centro de M & eacute;xico, incluida la cuenca de San Juan del R & iacute;o. Determinar la contribuci & oacute;n del flujo de agua subterr & aacute;nea profunda a los sistemas acu & iacute;feros volc & aacute;nicos poco profundos suele ser complicado, pero es importante en ambientes controlados tect & oacute;nicamente. En este estudio, se determin & oacute; la presencia y la tasa de flujo de agua subterr & aacute;nea profunda utilizando seis modelos hidrol & oacute;gicos diferentes. Mediante el uso de un modelo num & eacute;rico de agua subterr & aacute;nea con seguimiento de part & iacute;culas y la comparaci & oacute;n de simulaciones con datos de altura hidr & aacute;ulica y edad del agua subterr & aacute;nea, se seleccion & oacute; el escenario hidrol & oacute;gico m & aacute;s probable para la cuenca. Los resultados indican que un modelo que incorpora el flujo profundo, sin un aumento significativo de la conductividad hidr & aacute;ulica a lo largo de las fallas, es la mejor representaci & oacute;n del sistema entre los escenarios considerados. Esto pone de relieve la importancia de incorporar datos sobre la edad del agua subterr & aacute;nea, adem & aacute;s de los datos sobre la carga hidr & aacute;ulica, para limitar con precisi & oacute;n los reg & iacute;menes de flujo en los acu & iacute;feros, en particular los situados en regiones tect & oacute;nicamente activas con patrones de circulaci & oacute;n regionales. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)San Juan del Rio(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic). A & aacute;gua subterr & acirc;nea & eacute; a principal fonte h & iacute;drica em regi & otilde;es & aacute;ridas e semi & aacute;ridas do centro do M & eacute;xico, incluindo a bacia de San Juan del R & iacute;o. Embora a caracteriza & ccedil;& atilde;o da contribui & ccedil;& atilde;o do fluxo de & aacute;gua subterr & acirc;nea em sistemas de aqu & iacute;feros vulc & acirc;nicos rasos seja frequentemente desafiadora, ela & eacute; importante em ambientes tectonicamente controlados. Neste estudo, a ocorr & ecirc;ncia e a taxa de fluxo de & aacute;gua subterr & acirc;nea em profundidade foram caracterizadas usando seis modelos hidrol & oacute;gicos diferentes. Utilizando um modelo num & eacute;rico de & aacute;gua subterr & acirc;nea com rastreamento de part & iacute;culas e comparando simula & ccedil;& otilde;es com dados de carga hidr & aacute;ulica e idade da & aacute;gua subterr & acirc;nea, foi selecionado o cen & aacute;rio hidrol & oacute;gico mais prov & aacute;vel para a bacia. Os resultados indicam que um modelo que incorpora fluxo de & aacute;gua subterr & acirc;nea em profundidade, sem aumento significativo da condutividade hidr & aacute;ulica ao longo de falhas, & eacute; a melhor representa & ccedil;& atilde;o do sistema entre os cen & aacute;rios considerados. Isso destaca a import & acirc;ncia de incorporar dados de idade da & aacute;gua subterr & acirc;nea, al & eacute;m de dados de carga hidr & aacute;ulica, para restringir com precis & atilde;o os regimes de fluxo em aqu & iacute;feros, particularmente aqueles situados em regi & otilde;es tectonicamente ativas com padr & otilde;es de circula & ccedil;& atilde;o regional.