A project for modeling and isotopic analysis of artificial recharge in the Rialto-Colton basin aquifer in California, is discussed. The Rialto-Colton aquifer has been divided into four primary and significant flowpaths following the general direction of groundwater flow from NW to SE. The introductory investigation include sophisticated chemical reaction modeling, with highly simplified flow path simulation. A comprehensive reactive transport model with the established set of geochemical reactions over the whole aquifer will also be developed for treating both reactions and transport realistically. This will be completed by making use of HBGC123D implemented with isotopic calculation step to compute Carbon-14 (C14) and stable Carbon-13 (C13) contents of the water. Computed carbon contents will also be calibrated with the measured carbon contents for assessment of the amount of imported recharge into the Linden pond.