Forest Road Engineering Guidebook - Ministry of Forests

2. Design and Construction of Bridges and Stream Culverts
Introduction
Forest Road Engineering Guidebook
This chapter describes some of the activities and practices that precede and
follow the construction of forest road bridges and stream culverts. These
include:
• design requirements for bridges and stream culverts
• bridge and major culvert design responsibility
• site data and survey requirements for bridges and major culverts
• construction drawings and specifications for bridges, major culverts, and
stream culverts on fish streams
• site data and survey requirements for culverts on non–fish-bearing
streams
• estimating design discharge for streams
• statement of construction conformance and documentation.
The Forest Service Bridge Design and Construction Manual (B.C. Ministry
of Forests 1999) provides further discussion on planning, design, and construction
of forest road bridges.
Consistent with the Forest Road Regulation, in this chapter:
• “bridge” means a temporary or permanent structure carrying a road above
a stream or other opening
• “culvert” means a transverse drain pipe or log structure covered with soil
and lying below the road surface
• “cross-drain culvert” means a culvert used to carry ditchwater from one
side of the road to the other
• “major culvert” means a stream culvert having a pipe diameter of 2000
mm or greater, or a maximum design discharge of 6 m3 /sec or greater
• “stream culvert” means a culvert used to carry stream flow in an
ephemeral or perennial stream channel from one side of the road to the
other.
Refer to Chapter 4, “Road Drainage Construction” for further information on
forest road drainage systems including; temporary stream crossings, ditch
construction and cross-drain culverts, log culvert design and construction,
and ford design and construction.
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