This study finds that many small and medium-sized communities in Pennsylvania do not have clear or supportive local rules that encourage practices to manage rainwater and reduce flooding. These rules, such as those about what materials can be used in streets and parking lots, or what kinds of land uses are allowed in different parts of communities, can make it easier or harder to prepare for the effects of climate change. The researchers created a tool to examine how local laws in Pennsylvania communities support or limit nature-based practices for managing rainwater. They found that differences in household income, community size, and the type of sewer system were linked to whether local laws were more or less supportive of these practices. To design the tool, the researchers interviewed city staff, planners, and engineers across Pennsylvania to learn which kinds of rules matter most when trying to use green approaches for managing rainwater. Although the study focused on Pennsylvania, the approach could be used elsewhere to examine whether local laws help or hinder climate-friendly water practices. These findings could support better planning and policymaking in communities that want to be more prepared for heavy rainfall and rising temperatures.