Environmental Review Toolkit
Water, Wetlands, and Wildlife

Wildlife and Habitat

Restoration of Fish Habitat in Relocated Streams

CONTENTS

Preface
Introduction
Chapter 1 Flow In Natural Streams
Chapter 2 Fish Habitat
Chapter 3 Rehabilitation Concepts
Chapter 4 Habitat Restoration Measures and Structures
Chapter 5 Design of Relocated Stream Channels
Chapter 6 Construction of Relocated Channels With Habitat Structures
Chapter 7 Tenmile Creek-A Case Study in Stream Relocation

NOTICE
This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof.

The contents of this report reflect the views of the Office of Development of the Federal Highway Administration, which is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policy of the Department of Transportation.

This report DOES NOT CONSTITUTE A STANDARD, SPECIFICATION, OR REGULATION.

The United States Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear herein only because they are considered essential to the object of this document.


PREFACE

Occasionally, in constructing a highway, it may be necessary to encroach on a natural stream, or even to relocate the channel. In this event, the Federal Highway Administration believes that every effort should be made to restore the stream to a condition equal to that in which it existed before the highway construction.

This manual provides guidelines for the design and construction of relocated channels, and describes measures that will lead to rapid recovery of new channels by natural processes. Good design, and implementation of these measures can greatly reduce the adverse effects of stream relocation.

The literature on stream relocation and restoration is widely scattered in special reports and periodicals of limited circulation. In 1976, under a contract with the Federal Highway Administration, Dr. James R. Barton, of Brigham Young University examined the literature, and made extensive field studies of channel relocations in 12 States. This manual has been developed by Dr. Barton from these researches. Mr. Frederick W. Cron, of Lakewood, Colorado, assisted in the preparation of the text.

INTRODUCTION

Over the years, rivers and streams have been straightened, shortened, diverted, encroached upon, cleaned out and altered for many reasons. The consequences of this interference with nature have often been increased erosion and sedimentation, deterioration of aquatic life and a general loss of natural esthetics. However, these undesirable results are not inevitable. If good hydraulic design and construction practices are followed, a relocated stream can in time recover its esthetics and its value as a fishery.

Highway Locations in Stream Valleys

River and creek valleys are natural locations for railroads and highways because they generally require less cut and fill than other routes. However, they are ecologically fragile and easily damaged by construction, particularly construction which encroaches on the stream channel. Ideally, highways should be located to leave undisturbed ground between the road slopes and the watercourse. However, this is not always possible, and it may occasionally be necessary to encroach on the stream, or to cross and recross the channel.

Formerly, it was standard practice to divert streams into new channels in order to occupy the natural channel or reduce the number of culverts and bridges needed. It was easier and cheaper to improve the road alignment this way than to increase cuts and fills or build the additional structures. Preservation of fish habitat and stream esthetics received little attention, if, indeed, they were considered at all.

Concern for the whole highway environment now requires more thorough studies before streams are moved or disturbed. These studies should consider esthetic and natural values as well as construction, maintenance and operating costs. These evaluations should be made during the initial location of the highway, or, for an existing highway, before major relocations or improvements are undertaken.

Location by Interdisciplinary Teams

The modern trend is for highway locations to be made by teams combining the viewpoints and talents of a number of disciplines. Where there is a possibility that the location may encroach on the flood plain of a stream or require relocation of the channel, the team should include a hydraulic engineer and a fisheries biologist. The location team should study alternate locations, including one avoiding stream changes.

In the evaluation process the team should consider potential damage to the stream ecosystem. The highway engineer determines the probable encroachments on the stream due to construction. The hydraulic engineer estimates channel capacity and the possible effects of the highway's encroachment on the flood plain. The fisheries biologist determines fish populations, and estimates their ability to survive or recover from the physical impacts of construction. The landscape architect recommends measures to restore the esthetics of the area. As a group, they combine ideas and solutions to produce a plan that will fulfill the engineering requirements for the highway with the least damage to the stream.

When stream relocations are necessary, they should be as carefully planned and constructed as the highway itself, using the interdisciplinary approach. This means providing a stable channel of adequate hydraulic capacity, and naturalizing the new channel by restoring fish habitat and planting trees and vegetation to regenerate the original bank conditions as rapidly as possible.

The following chapters will review principles and practices that have proven effective for restoring natural conditions in relocated streams with coarse material beds. In such streams adherence to these measures will greatly reduce losses of environmental quality caused by highway construction.

Questions and feedback should be directed to Dan Buford (Daniel.Buford@dot.gov, 202-366-8168).

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