The present invention discloses designating two different treatment zones in a large body of water. The first zone is a sedimentation zone. This zone is used mainly to provide treatment and settling of microorganisms and/or contaminants to inactivate and/or remove them from the water body. In this zone a disinfection method based on a CT index and applying an efficient amount of a flocculant composition may be used. The second zone is a dissipation zone. This zone is where main direct contact recreational water activities are intended to occur. In the dissipation zone a water flow is established that, along with the natural currents produced by winds and/or water temperature differences, generate a water dissipation pattern of the volume of water within the dissipation zone into the sedimentation zone. In addition, continuous disinfection of the water volume in the dissipation zone is preferably provided by maintaining a permanent chlorine residual.