Slack tidal flows through all structures are
about 90 minutes past high tide.
Bair Island has had modifications
to restore pre-industrial tidal flow to this wetland while not adversely affecting
the Port of Redwood City and upper Redwood Creek (with increased silting and flow).
The effort was led by US Fish & Wildlife
and contracted out to Ducks Unlimited for the work.
BIAC was involved in 2011 and early 2012 in understanding the plans
and ensuring that public aquatic access would remain reasonable
during and after construction.
in 2012 and early 2013 access to Corkscrew and Smith Sloughs was
interrupted, yet the result is a whole new world
of aquatic adventures. Landings on Bair Island are still be
prohibited, but smart attention to tidal patterns will present you with a new
adventures and public access to a stunning wetland and
wildlife preserve. The usual paths around Bair Island have many new tidal
flows and areas to explore. Watch for squirrely marine flows in and out of the
new levee breaches as well as shifting mud flats. These new flows
will scourge out Steinberger Slough - a process that
will continue for decades.
You can follow the
changes starting today or enjoy them anytime.
Click on the
for a detailed plans of the work.
Basically the work involves:
Two "Flow Restrictors" have been built - one halfway
through Corkscrew Slough (FR1) and the other halfway up Smith Slough
(FR2) - to prevent additional tidal flow and silting into
Redwood Creek and the Port of Redwood City (saving million$ in dredging
fees). These micro dams encourage more tidal flow into Bair Island from Steinberger
Slough to the north and should scourge out a deeper channel there as more water
flows in and out each day. These structures will still allow aquatic
access through Corkscrew and Smith at current tide levels
(5' and 2' respectively).
The old salt pond levees inside of
Middle and Outer Bair Island are breached in many places to restore
former sloughs and to recreate the original tidal wetlands of Bair
Island. See the image below for details. These breaches are
about 50' wide and create new tidal rushes in and out during ebb and flows
- so watch for marine flows that could upset your paddling or rowing.
At the time of this
writing (February 2013) the Corkscrew (FR1) and Smith (FR2)
Restrictors are complete as are the Outer and Middle Bair Island breaches. The
dynamic current flows are hazardous. At peak flows the drop from one side to the other can be as
much as 3 feet.