Climate Chang Challenge
The Statewide Hydraulic Model as a Stream Crossing Planning Tool will assist municipalities replace undersized and/or failing stream crossings (e.g., culverts, small bridges) ultimately mitigating climate change impacts from freshwater ecosystem degradation.
Project Alignment with ResilientMass Plan Priority Actions
This project is the development of innovative cost-effective tools and modeling to assist in simplifying and expediting culvert and bridge sizing to help provide improved flood resiliency, aquatic organism passage, stream continuity, and river and floodplain processes. These initiatives align with the 2023 State Hazard Mitigation and Climate Adaptation Plan by reducing flood risk and supporting equitable restoration projects with communities and has the potential to address elements of all priority impacts.
Climate Resilience Project Scope
Many of the 25,000 plus roadway crossing structures (small bridges and culverts) over rivers and streams in Massachusetts are undersized (Massachusetts Culverts and Small Bridges Working Group, 2020). This has resulted in substantial impacts not only on fish and wildlife movement and habitat connectivity, but also to the survival of organisms and populations. Additionally, undersized structures lack the resiliency needed to withstand large floods and potential changes in flood magnitude and frequency. Over the next 10-20 years, thousands of culverts will need to be replaced due to age and deterioration. Massachusetts has a critical opportunity to improve stream crossings and enhance resiliency, public safety, and environmental goals. However, due to limited resources, municipalities are currently replacing failing culverts in-kind (i.e., undersized culverts get replaced with undersized culverts).
By integrating data from hydrological models, crossing assessments, and aquatic connectivity models, the tool will provide municipal highway departments and other interest groups a preliminary design (i.e., includes a span, pipe, and box culvert designed to 10-, 25-, 50-, and 100-yr flows and the full Stream Crossing Standards) used for budgetary planning, funding applications, and watershed approach - prioritization purposes. The online tool will facilitate a shift away from culvert replacement in-kind, thereby enabling Massachusetts’ communities to reduce the risk and cost of flooding / storm damage, enhance stream ecology, and improve public safety / disaster response.
Metrics and Results
Ultimately, the overall success of the Statewide Hydraulic Model as a Stream Crossing Planning Tool will be determined by its implementation and use by towns, cities, planners, and engineers to prioritize and fund resilient stream crossings that provide adequate organism passage throughout the Commonwealth. The results of the project will be an online tool located within the existing USGS StreamStats website, along with education and outreach material. The urban peakflow equations deliverable specific to this Phase will be published through USGS.
Best Practices and Lessons Learned
As part of its best practices, this study has community outreach built into its objectives in the form of online available videos and trainings to use Streamstats and literature. This will be implemented and delivered in the future.
Further Action
Additional phases will be needed to further scale the project statewide and provide adequate education and outreach to all communities and towns.
Additional Information and Resources
The Statewide Hydraulic Model Project website lists all the Phases and deliverables, along with current education and outreach information.