Wetland provides important ecosystem services and store carbon dioxide but is also an important global source of GHG mainly carbon dioxide and methane- a potent greenhouse gas. In order to understand the dynamics of carbon budget for our study area; Rampillon buffer zone is an artificially constructed wetland designed to capture the titled agricultural drainage located near Nangis in Seine-et-Marne in order to improve the surface water quality. Quantifying and understanding the environmental drivers of carbon sequestration from the wetland is important in order to have a better understanding of the current and the future GHG budget of aquatic systems and the global ecosystem as a whole. In this study, we present the observation of carbon storage in sediment coming from agricultural drainage for the year 2017-2018, carbon captured in the vegetation during the growing season of the year 2018, observation of total inorganic and total organic carbon dissolved in the water by continuous measurement via SCAN spectrophotometer since year 2014-2018, observation of CO2 fluxes by Eddy Covariance tower installed at the site during the one full year or one full growing season of 2017 and measurement of methane fluxes by Automatic Chamber method done via four campaigns held from May 2014 to October 2015. We found that, wetland acts as higher carbon sink via sediment than the vegetation with 2.3±0.248t C- CO2 of Total Carbon added each year by sediment compared to only 11.5kg C or 42.24kg CO2 eq via vegetation. Using Eddy Covariance tower to measure CO2 fluxes, we determined that the wetland is net carbon source with ~1005kg C- CO2 been released into the atmosphere annually; primarily correlated to ecosystem respiration during the winter indicating the role of soil temperature, microbial activity and atmospheric pressure. Methane fluxes were measured by automatic chamber during the four campaigns resulted in wetland being source of CH4 releasing 40.85kg CH4-C or 1021 kg CO2eq per year; we found distinct diurnal and seasonal pattern of flux rates with ebullition acting as the dominant transport pathways contributing 89% of total emissions. We conclude that the temporal dynamics of methane emissions over the seasonal and diurnal times scales should not be ignored. By studying all the compartments of an artificial wetland and calculating Net carbon budget, we can conclude that Rampillon since its construction i.e. in last 8 years, is a carbon sink with 2.3t C- CO2 or 8.4t CO2eq net carbon being stored in the wetland every year with sediment being foremost dominant compartment whereas from Net gas budget; a carbon source with 12.6t CO2eq of carbon dioxide and 1.02t CO2eq of methane gas fluxes emitted every year. Further studies are required to investigate many other factors in depth such as soil temperature, atmospheric pressure, relative humidity, microbial activity, photosynthetically active radiation along with reducing the percentage of uncertainties of each compartment to have much deeper understanding of the GHG contributi