Understanding how humans and ecosystems interact across landscapes is an importantchallenge for the development of sustainable societies. Human dominated landscapes arefrequently heterogeneous in their distribution of ecosystems and the associated goods andservices. It can be difficult to create management strategies that cater to diverse demandsfrom different resource managers, while at the same time promoting healthy functioningof ecosystems held in common. I use a social network perspective to analyze howmunicipal management units connect to each other with regards to a water resource intwo watersheds in Québec, Canada. I test the importance of collaborative network ties formunicipalities’ engagement in water quality management activities. I assess ifmunicipalities with different ecosystems, namely agriculture and tourism, engagedifferently in water quality management activities and if they have different socialnetworks. I assess the role of third party actor groups such as Government Ministries andNon-Governmental Organizations that connect municipalities across the diverselandscape. Third party actor groups are instrumental in connecting municipalities acrossa diverse landscape. Municipalities with ecosystems facilitating tourism have morecollaborative ties in the water quality management network and are more engaged inwater quality management activities than municipalities managing for agriculturalproduction. An asymmetry in collaborations and activity engagement for water qualitymanagement has implications for the capacity of the region to encourage basin scalewater management.