Culvert AOP Grant: Federal Funding for Fish Passage and Culverts (FY 2026)

The Federal Highway Administration's (FHWA) National Culvert Removal, Replacement, and Restoration Grant Program — known as the Culvert Aquatic Organism Passage (AOP) Program — provides federal funding to states, local governments, and tribes to replace, remove, or repair culverts and weirs that improve or restore fish passage. For communities whose undersized or failing culverts both block migrating fish and flood local roads, this program offers a chance to solve two problems with one project.

What Is the Culvert AOP Program?

Created by the Bipartisan Infrastructure Law, the Culvert AOP Program funds projects that replace, remove, or repair culverts or weirs in a way that meaningfully improves or restores passage for anadromous fish. Anadromous fish are born in freshwater, spend most of their lives in saltwater, and return to freshwater to spawn — salmon are the most familiar example.

Aging road-stream crossings are one of the most common barriers to fish migration in the country. The same undersized culverts that block fish also tend to constrict stream flow, scour roadbeds, and wash out during high-water events. Replacing them with properly sized, stream-simulating structures restores aquatic habitat while making local infrastructure more resilient to flooding.

Who Can Apply?

The Culvert AOP Program has broad eligibility for the public entities most likely to own road-stream crossings:

• States
• Units of local government — counties, cities, towns, and similar jurisdictions
• Indian Tribes

This wide eligibility makes the program especially relevant to coastal and river-basin communities in the Pacific Northwest, Alaska, the Great Lakes, New England, and other regions where anadromous fish runs intersect with local road networks.

What Projects Are Eligible?

Eligible projects are those for the replacement, removal, or repair of culverts or weirs that:

1. Would meaningfully improve or restore fish passage for anadromous fish; and
2. With respect to weirs, may also include (a) infrastructure to facilitate fish passage around or over the weir, and (b) weir improvements, as authorized under 49 U.S.C. § 6703(b).

In practice, the strongest projects pair a clear ecological benefit — reopening miles of upstream spawning habitat — with a tangible infrastructure benefit, such as eliminating a chronic washout point or restoring a road's design flood capacity.

Cost Share

The Culvert AOP Program requires a non-federal match. However, the program provides for a reduced or waived match for projects that serve Tribal governments and economically disadvantaged communities, consistent with the program's equity goals. Review the current Notice of Funding Opportunity for the exact federal share and any available match reductions before finalizing your budget.

How to Apply

Applications are submitted through Grants.gov. Make sure your organization's federal registrations are current well before the deadline:

• An active SAM.gov registration
• A valid Unique Entity Identifier (UEI)
• A Grants.gov account for your organization

Tips for a Competitive Application

1. Quantify the Habitat Benefit

Document how many stream miles or how much spawning habitat the project reopens, and which fish species benefit. Coordinate early with your state fish and wildlife agency, NOAA Fisheries, or a tribal natural-resources department to ground your claims in recognized data.

2. Tell the Dual-Benefit Story

Culvert AOP projects compete best when they deliver both ecological and infrastructure value. Show how the crossing currently floods, scours, or restricts traffic, and how a right-sized replacement improves road resilience alongside fish passage.

3. Use Stream-Simulation Design

Reviewers favor designs that mimic natural stream conditions — appropriate width, slope, and bed material — rather than simple pipe swaps. Engaging an engineer experienced in aquatic organism passage design strengthens both the project and the application.

4. Build Partnerships

Letters of support and cost-share contributions from tribes, watershed councils, conservation groups, and state agencies demonstrate broad backing and can help offset the non-federal match.

Contact Information

• Program Website: highways.dot.gov — Culvert AOP Program
• Grants.gov Support: support@grants.gov

How Avila Can Help

Culvert AOP applications sit at the intersection of transportation engineering and aquatic ecology, and they require applicants to translate technical fish-passage and hydraulic data into a compelling narrative. For local public works and natural-resource staff, assembling that case under deadline can be demanding.

Avila's AI-powered platform helps local governments and tribes streamline the grant application process by:

• Analyzing the NOFO to surface eligibility and scoring criteria
• Helping draft narratives that connect habitat and infrastructure benefits
• Tracking deadlines and required registrations
• Managing the full grant lifecycle from discovery to closeout

Ready to explore how Avila can support your Culvert AOP application? Book a demo to learn more.

For more on federal grant applications, see our guides on federal grant writing, SAM.gov registration, and Grants.gov registration. For other infrastructure funding, explore our guides to the BIT3 Bridge Program and the Nationally Significant Federal Lands and Tribal Projects Program.