New York

Improving Road and Stream Crossings

Where the River Meets the Road

Read a summary of the economic analysis of improved road-stream crossings.

Economics of Improved Road-Stream Crossings

Read the full analysis of the economic, social, and ecological benefits of well-designed culverts, as well as the key role they can play in adapting infrastructure to a changing climate.

Underneath New York’s highways and roads lay more than one million culverts—drains that connect thousands of stream segments. Effective culverts permit water and wildlife to travel without interruption. But recent severe storms have also brought to light the importance of culverts and the role they can play in helping communities become more resilient in a changing climate.

Why do New York's culverts need to be improved?

When culverts are too small, both human communities and aquatic ecosystems may be at risk. As many communities across the Northeast saw in the wake of Hurricane Irene, culverts are more likely to blow out during floods, creating safety hazards, potentially damaging roads, structures and property, and requiring replacement. These failures are expensive: in addition to the hard costs associated with infrastructure repair, there are a cascade of other costs to local businesses in terms of lost revenues when roads are impassable or rivers can no longer support economically important species like brook trout.

On the other hand, larger culverts without bottoms, for instance, allow fish to cross under roads more safely to reach spawning areas and coldwater havens. They also allow higher water volumes and floating debris to pass through—reducing the risks of flooding that can damage homes and property.

What is The Nature Conservancy doing?
  • Helping the NYS Department of Transportation identify places where culvert upgrades would have the greatest impact on improving stream crossings for fish and wildlife while also keeping roads safe for people. In the wake of recent storms, the Conservancy has also recognized that strategic replacement of inadequate culverts can go a long way toward protecting wildlife habitat and making communities more resilient to strong storms.
  • Mapping priority culvert upgrades: While solutions to problematic culverts are readily available, the costs for upgrades or retrofits can be significant. That’s why the Conservancy developed a prioritization tool that is now being used in the Ausable watershed, which drains into Lake Champlain. Future work will include expanding this tool statewide to help NYSDOT focus its limited resources toward culvert projects that meet the agency’s triple bottom line to address ecological, economic and social needs.
  • Working with partners: In a related project, the Conservancy recently teamed up with non-profit and government partners to field survey almost 400 road/stream crossings in the Lake Champlain and lower Hudson regions to assess their conditions in terms of biological importance, vulnerability to flooding, and other safety issues. Mapping and ranking these sites will help highway maintenance crews get the most out of their budgets.
  • Analyzing economics: The recently released Conservancy report, An Economic Analysis of Improved Road-Stream Crossings, highlights the economic, social, and ecological benefits of well-designed culverts as well as the key role they can play in adapting infrastructure to a changing climate. The report presents the monetary trade-offs of investing in well-designed culverts in the short and long-term, current economic and regulatory constraints for implementing well-designed culverts, and recommendations for moving forward at scale.
What is the future of this project?

Looking forward, the Conservancy aims to take its work and partnership with NYSDOT to the next level, using the culvert database as a foundation for incorporating climate vulnerabilities into transportation and design plans.

Conservancy scientist Michelle Brown, the project lead, says this work shows the importance of improving climate resilience locally. “Freshwater and climate resilience work go hand in hand,” says Brown. “Based on our current work, we have determined which areas can achieve the most ‘bang-for-the-buck’ in terms of meeting ecological, social, and economic goals, and now we need to focus on these places to build their resilience.”

Brown also emphasized that the NYS 2100 Commission report highlights culverts specifically as a way to protect against future storms and flooding. “This will help as we move forward in replacing older designs with new designs,” she says. “Our work is about building resilient natural communities and building resilient human communities,” says Brown, and the Conservancy’s continued efforts on culverts may be able to do just that.  

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