This research explores the effects different cooperation levels between countries have on water resources from a shared river. The water resources that are taken into account are: hydro electricity generated per dam, water that flows to the environment per dam, and irrigation water per station. The Zambezi river basin is selected as study area due to its trans-boundary multi-stakeholder complex character. The cooperation levels that are explored are no cooperation, full cooperation, and section cooperation. No cooperation entails that every hydroelectric dam in the river only tries to maximize its own electricity. With full cooperation the dams releases are adjusted to benefit all the water resources in the whole basin. With section cooperation the dam releases are adjusted to maximize the water resources within the section of the specific dam. A section is a geographical area that is based on country borders. A simulation model is built in order to explore the effects of the different cooperation levels. The release policies that maximize the water resources for full and section cooperation are found with a multi-objective evolutionary algorithm (MOEA). From this research three findings are extracted. First, for the full cooperation level and the section cooperation level policies exist that dominate the no cooperation level policy for every examined water resource. Moreover, for these water resources found policies for either full or section cooperation produce similar results. Therefore, any of the explored cooperation forms could be more beneficial than no cooperation at all. Second, outcomes of this study indicate that owners of water resources located in the upstream of the river have less possible benefits from entering a cooperation agreement in which their dams have to adjust their release policy. These water resources can only improve by a small amount compared to water resources located in the downstream of the river. Third, policies do exist that are able to perform best for certain water resources, but also cause other water resources to decline to lower than their no cooperation value. Therefore, selecting fitting release policies is important since not every found policy leads to a better solution. Last, in this study best performing policies for electricity production and irrigation for both full and section cooperation are compared. It is discovered that adapting the best electricity policy for either one of the cooperation forms would be most beneficial for the involved stakeholders. This is due to the electricity policies having the highest relative resource gains. To conclude, cooperation in a river basin could result in an overall increase in water resources. However, reaching cooperation might prove to be difficult, because of the lower incentives for the stakeholders in the upstream of the river. Furthermore, extra care has to go towards selecting better performing policies, because policies exist that can cause a decline in water resources compared to when there is no cooperation in the river basin. Moreover, stakeholders are expected to select the policy that maximizes the electricity production, since these policies also perform well for other examined water resources.