Highway Departments as Watershed Stewards – Trans-jurisdictional Challenges and
Opportunities for Reducing Flooding

Highway departments play a critical role in directing waterflow across the landscape. Models show that the linear infrastructure of roadside ditch networks can disrupt over 20% of runoff at the small watershed (HUC-14) scale. Ditch networks readily criss-cross every watershed, re-directing stormwater paths independent of jurisdictional boundaries. We argue that highway departments have one of the biggest and most significant impacts in shaping hydrologic flows within watersheds, creating a strategic opportunity for highway departments to decrease pollution, reduce flood risks, and have an overall positive impact on watershed health.
Few highway departments in the U.S. operate with an awareness of their watershed-scale impacts. In part this is because their primary mission is to focus on roadway safety, with no explicit mandates to prioritize environmental impacts. Additionally, each state has different highway management structures. In New York State, 933 Town Highway Departments are responsible for maintaining over 76,000 centerline miles of roads -- almost 70 percent of the state’s roadways. This large number of small-scale, independently-managed departments makes it difficult to operate with a focus on broader watershed-scale impacts that occur outside of an agency’s political boundaries.
Before policy makers can advocate for watershed stewardship efforts by highway departments, is it necessary to understand the current operational practices, collaboration efforts, and challenges faced by these departments. We extensively surveyed NYS Town Highway Superintendents to understand their practices, particularly regarding cross-jurisdictional collaborations and stormwater management. 296 surveys were returned with a 38% survey success rate. We identified that 39% of respondents did not collaborate with any other jurisdictions on drainage management. 20% of towns collaborated with one neighbor, and 21% collaborated with 2 neighbors. Most common reasons for collaboration were a neighboring town’s willingness to collaborate, sharing different equipment, and addressing transboundary stormwater runoff. Flooding was a reoccurring challenge, however the frequency of flooding was not clearly correlated with the number of collaborating towns. When asked if their town could benefit from more collaboration, responses were varied. Towns that currently do not collaborate were the least interested in collaborating (41%) in the future. Conversely, towns that currently collaborate with two or more jurisdictions indicated the strongest interest in collaborating with others, suggesting opportunities and strategies to grow collaborative networks.
Our research fits well with the 2023 ICOET theme of “Synergy at Scale: Partnering for a Healthy Landscape.” This presentation will be anchored in the challenges and realities of current management structures, but we will propose an aspirational vision of supporting highway departments to become watershed stewards.