Publication No. FHWA-HIF-11-008 October 2010

U.S. Department of Transportation Federal Highway Administration

Hydraulic Engineering Circular No. 26, First Edition

CULVERT DESIGN FOR AQUATIC ORGANISM PASSAGE

Federal Lands Highways

Technical Report Documentation Page 1. Report No. FHWA-HIF-11-008

HEC-26 2. Government Accession No. 3. Recipients Catalog No.

4. Title and Subtitle

Culvert Design for Aquatic Organism Passage Hydraulic Engineering Circular Number 26

5. Report Date October 2010

6. Performing Organization Code

7. Author(s)

Roger T. Kilgore, Bart S. Bergendahl, and Rollin H. Hotchkiss

8. Performing Organization Report No.

9. Performance Organization Name and Address

Kilgore Consulting and Management Denver, Colorado

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

13. Type of Report and Period Covered

Final Report 11/1/07 11/30/09

12. Sponsoring Agency and Address

Central Federal Lands Highway Division 12300 West Dakota Ave. Lakewood, Colorado 80228

14. Sponsoring Agency Code

15. Supplementary Notes

Contracting Officers Technical Representative: Bart Bergendahl Technical Support: Christopher Goodell, Alan Johnson, Philip Thompson, Steve Rainey, Christopher Frei

16. Abstract

This document presents a stream simulation design procedure, methods and best practices for designing culverts to facilitate aquatic organism passage (AOP). The primary goal of this document is to incorporate many of the current geomorphic-based design approaches for AOP while providing a procedure based on quantitative best practices. It presents a bed stability-based approach that accounts for the physical processes related to the natural hydraulic, stream stability, and sediment transport characteristics of a particular stream crossing. Specific information on fish, or other aquatic organisms, is not required, but should be incorporated when required. The document provides a context for stream crossing design and describes the applicability of the design procedure. It also provides important background information a designer should be familiar with including how culverts create barriers, techniques for culvert assessments and inventories, fish biology, fish passage hydrology, stream geomorphology, construction, and post-construction. Detailed technical information supporting the practices used within the design procedure and several design examples are included in the appendices. The core of the document is a 13-step design procedure. Step 1 involves determination of the hydrologic requirements for the site for both flood flows and passage flows. Step 2 defines the project reach and establishes the representative channel characteristics appropriate for the design. Steps 3 and 4 are to identify whether the stream is stable (Step 3). If not, channel instabilities are analyzed and potentially mitigated (Step 4). In Step 5, an initial culvert size, alignment, and material are selected based on the flood peak flow. Subsequently, the stability of the bed material is analyzed under the high passage flow (Steps 6 and 7) and flood peak flow (Steps 8 and 9). Steps 10, 11, and 12 focus on the velocity and depth in the culvert. However, these parameters are not compared with species-specific values, but rather are compared with the values upstream and downstream of the culvert insuring that if an organism can pass the upstream and downstream channel, it will also be able to pass through the culvert. Step 13 allows the designer to review the completed design.

17. Key Words:

Culvert design, Aquatic organism passage (AOP), Fish passage

18. Distribution Statement

No restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of Pages

234

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

ACKNOWLEDGMENT

Kilgore Consulting and Management (Roger Kilgore, P.E., Principal) prepared this first edition of HEC 26. In addition to Mr. Kilgore, the project team included Rollin Hotchkiss, Ph.D., P.E. (Brigham Young University), Christopher Goodell, P.E. (WEST Consultants), Alan Johnson (Aquatic Resource Consultants), Philip Thompson, P.E. (independent consultant), Steve Rainey, P.E. (Fish Passage Engineer, GEI Consultants), and Jeff Bradley, Ph.D., P.E. (WEST Consultants).

The work performed by Rollin Hotchkiss and Christopher Frei in FHWAs Design for Fish Passage and Road-Stream Crossings: Synthesis Report (2007) was used to identify a broad range of background material and references.

The work was completed under the direction of FHWAs Project Manager, Bart Bergendahl, P.E., who also contributed significantly to the content of this document.

Several reviewers from a Technical Advisory Committee and the FHWA contributed comments, corrections, and suggestions. These contributors were:

Technical Advisory Committee Mike Furniss United States Forest Service

Robert Gubernick United States Forest Service

Charles Hebson Maine Department of Transportation

Andrzej Kosicki Maryland State Highway Administration

Bryan Nordlund National Marine Fisheries Service

Mark Weinhold United States Forest Service

Marcin Whitman California Department of Fish and Game

FHWA Larry Arneson Hydraulics Engineer

Eric Brown Hydraulics Engineer

Mark Browning Hydraulics Engineer

David Carlson Environmental Specialist

Stephen Earsom Environmental Specialist

Paul Garrett Ecologist

Mary Gray Environmental Specialist

Scott Hogan Hydraulic Engineer

Kevin Moody Environmental Specialist

Melissa Schnier Environmental Biologist

i

TABLE OF CONTENTS Page

ACKNOWLEDGMENT..................................................................................................... I TABLE OF CONTENTS.................................................................................................. II LIST OF TABLES ........................................................................................................ VIII LIST OF FIGURES ......................................................................................................... X GLOSSARY .................................................................................................................. XII GLOSSARY OF ACRONYMS .................................................................................. XVIII LIST OF SYMBOLS ..................................................................................................... XX

CHAPTER 1 - INTRODUCTION .................................................................................. 1-1 1.1 PURPOSE ......................................................................................................... 1-1 1.2 CONTEXT ......................................................................................................... 1-2

1.2.1 Historical Crossing Design.................................................................. 1-2 1.2.2 Road Stream Interaction ..................................................................... 1-2

1.3 DESIGN PROCEDURE APPLICABILITY .......................................................... 1-3 1.4 MANUAL ORGANIZATION ............................................................................... 1-3

CHAPTER 2 - CULVERTS AS PASSAGE BARRIERS .............................................. 2-1 2.1 STREAM FRAGMENTATION............................................................................ 2-1 2.2 BARRIER MECHANISMS ................................................................................. 2-2

2.2.1 Drop at Culvert Outlet ......................................................................... 2-2 2.2.2 Outlet Pool Depth ............................................................................... 2-2 2.2.3 Excessive Barrel Velocity ................................................................... 2-3

2.2.3.1 Boundary Layer Velocity ...................................................... 2-3 2.2.3.2 Average Velocity .................................................................. 2-4 2.2.3.3 Maximum Point Velocity ....................................................... 2-4 2.2.3.4 Inlet Transition Velocity ........................................................ 2-4

2.2.4 Insufficient Depth ................................................................................ 2-4 2.2.5 Excessive Turbulence ........................................................................ 2-4 2.2.6 Culvert Length .................................................................................... 2-5 2.2.7 Debris and Sediment Accumulation .................................................... 2-5 2.2.8 Culvert Damage .................................................................................. 2-5

CHAPTER 3 - AOP CULVERT ASSESSMENT AND INVENTORY ............................ 3-1 3.1 AOP CULVERT ASSESSMENT ........................................................................ 3-1

3.1.1 Assessment Criteria ........................................................................... 3-1 3.1.2 Degree of Barrier ................................................................................ 3-1 3.1.3 Data Collection ................................................................................... 3-2

3.2 CULVERT INVENTORY ..