Teichi bog is largest intact moss bog in the Baltics states. The article considers the hydrological exchange process of the bog and surrounding areas. It plays an important role in the ecosystem, as well as a factor in stabilizing the water level, as bog peat in its natural state contains 88%-97% water. It belongs to raised bogs, since its upper layer is located above the surrounding relief. Replenishment of water resources in the Teichi Nature Reserve occurs mainly due to precipitation. In turn, the bog with surface runoff and groundwater flow returns excess moisture, thus feeding nearby streams. The reserve area and surroundings modeled in the Groundwater Vistas environment over a 35 km × 40 km area, with a plane approximation step of 20 m. The hydrogeological model contains seven layers, 24.5 million nodes. The model includes several rivers, lakes and a wide network of drainage ditches, both embedded in the relief and attached as boundary conditions. A novelty is the assignment of different filtration coefficients to the bog. The process of water movement studied by calculating water balances, as well as by performing particle tracing simulations. Result of the research - it was found that there is an intensive interaction of the bog with nearby watercourses. The protection zone of the bog was determined using the results of tracer simulation - movement time and trajectory over a period of 25 years.