Drained peatlands (peat areas where ditches have been excavated to enhance plant production) are one of the main sources of carbon dioxide emissions globally. Blocking these ditches by building dams is a common strategy to restore the self-sustaining peat ecosystem and mitigate carbon dioxide emissions. Where should these dams be located in order to maximize the benefits? Our work tackles this question by making use of the available data, hydrological modeling and numerical optimization methods.