USDA Forest Service Update

March 2014

SUBJECT: Aquatic Organism Passage

Issue: Unless properly designed and constructed, road-stream crossings can hinder or obstruct the upstream 

movement of fish and other aquatic and riparian-dependent organisms, while they may also be inadequate to pass 

high flows, flood events and debris and therefore sustain damage and failure.

Key Points:

• Re-establishing aquatic organism passage (AOP) and providing adequate high flow passage is a key 

component of restoring ecological conditions by connecting fragmented habitats and protecting infrastructure 

investments. Passage is often a first step in restoring watershed condition, which benefits fish and other 

aquatic and riparian species.

• Stream Simulation Design is the preferred approach to ensuring unimpeded access for all life stages of aquatic 

organisms beneath road and trail infrastructure.

• Regional assessments indicate that over 40,000 road-stream crossings potentially block access for aquatic 

organisms and use of upstream habitat. Many forests are currently involved in comprehensive road-stream 

crossing and trail-stream crossing assessments for prioritization.

• National interest drives partnerships across other Federal, State and local agencies, Tribes and non-profit 

groups. Partners include U.S. Fish and Wildlife Service, NOAA Fisheries, State Departments of 

Environmental Quality or Departments of Conservation, State and County Departments of Transportation, 

U.S. Army Corps of Engineers and Trout Unlimited.

• Research and analyses following large-scale flood events across the country have verified the flood resiliency 

of the Stream Simulation Design approach and its cost-effectiveness in protecting infrastructure, community 

access and maintaining ecological connectivity.

• Forest Service (FS) is recognized as a national leader in road crossing techniques that ensure AOP, and the 

FS’s Stream Simulation Design approach is recognized as the standard for stream crossing designs.

Background: Efforts over the past 20 years have focused on adult sport fish. Assessments from the past decade 

confirm the ecological importance of providing passage to all native aquatic and riparian species dependent on 

movement through road-stream crossings and for all life stages of those species, particularly to provide for robust 

communities and for resilience to climate change stresses. AOP at road-stream crossings represents one of FS’ 

best examples of internal integration and quantifiable, on-the-ground restoration with strong partner support.

Funding & Accomplishments1:

FY 2011 FY 2012 FY 2013

SAFETEA-LU funding2 $10,000 $10,000 est. $0

Legacy Roads and Trails funding3 $90,000 $45,000 $45,000

Number of structures replaced for AOP 300 275 TBD

Miles of aquatic habitat accessed-HTAP 142 242 0

Miles of aquatic habitat accessed-CMLG 215 179 119

Total miles of aquatic habitat restored4 710 650 251 1/

Funding $ displayed in thousands. 2/

Safe, Accountable, Flexible, and Efficient Transportation Equity Act Legacy for Users (SAFETEA-LU) with HTAP (Highway Trust Funds for 

Aquatic Passage) funding

4/

Total miles of aquatic habitat restored for AOP is accomplished through HTAP, CMLG and other budget line items not necessarily shown above

Contacts:

Rob Harper, Director, Watershed, Fish, Wildlife, Air and Rare Plants, 202-205-1671.

Nat Gillespie, Assistant National Fisheries Program Leader, 202-205-7827.