Collaboration in governing complex environmental challenges is the norm. However, collaboration does not necessarily deliver desirable outcomes, and the importance of forming collaborative networks that effectively address the challenges at hand has been emphasized in theory and practice. Evidence for what constitutes a suitable network structure is still scarce, and the understanding of what factors drive collaboration that constitutes such networks is limited. Utilizing a comparative approach, this study elucidates if and how varying political attention impacts the social tie formation among municipal street- level bureaucrats addressing flood risk mitigation in their daily work. Our results show that political attention, conceptualized as saliency and a broad framing of the issue, has a marked effect on network formation processes. When political attention is low, water & sewage experts (technical experts) dominate tie formation, while politicians and senior managers (decision makers) and planners (cross- sector experts) increase their relative efforts in forming collaborative ties when political attention is high. Further, political attention is also positively associated with appointed coordinators' abilities to collaborate with others. Both these processes coincide with desirable governance outcomes. Our study of local- level collaborative governance demonstrates a need to better understand the nexus of political attention, collaborative network formation, and environmental governance outcomes.