Northern San Luis Obispo County Coastal Trail Master Plan

Northern San Luis Obispo County Coastal Trail Master Plan
construction requires nearly the same level of site access and foundation support as a steel bridge, and the life
span of wood is limited. Short wood trail bridges may be the best alternative where the span is as short as 8 to
20 feet. Below 8 feet the structure is assumed to be a boardwalk.
Boardwalks and Puncheons
These are described under trail types because they are defined by location on the recommendations maps.
There may be little structural or cost difference between a boardwalk and a wood trail bridge. A puncheon is a
very low boardwalk that doesn’t require railings, and will typically be less expensive than a bridge or
boardwalk.
Seasonal Bridges
As discussed under Long Span Trail Bridges, the
constraints and process for implementing a major
trail bridge are significant. At least one of the major
drainages, Arroyo de la Cruz, has been studied in
detail by DPR’s Trail Designer, who concluded that
the only viable solution, although an undesirable one,
is a “seasonal pipe bridge” - a pedestrians-only
structure that is supported on pipes driven into the
creek bed, as shown in the photo.
The bridge structure is removed each year before the
rainy season, and re-installed in the Spring. This
option is a last resort because DPR and other
agencies do not have sufficient staff to place, remove
and maintain such bridges. They may be
objectionable to environmental agencies such as the
Department of Fish and Game as they intrude into the
stream channel, and have a minor impact during their
annual placement and removal, and could be
destroyed and cause further impacts if not removed
before a high flow event. Finally, they are less than
ideal for accommodating trail users because they are
seasonal, and are not likely to be accessible for people
with disabilities.
An alternative seasonal bridge type could be a
suspension bridge as in the adjacent photo. This may reduce impacts on the channel, but would have the same
or worse issues of usability and accessibility.
4.2.6 Sidepaths
Where warranted to protect sensitive resources, or where there is insufficient physical space or lack of public
access, or to cross a drainage on an existing highway culvert, the CCT may be routed in the State right-of-way
adjacent to Highway 1. A two-way multi-use trail or path that is routed in the right-of-way adjacent to a
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Seasonal “pipe bridge” on the Eel River
Temporary suspension trail bridge