Joined: 03 Apr 2000
|Posted: Thu Jan 11, 2001 12:42 pm Post subject: Crissy Field News
|Info about the current status of Crissy follows. Anyone have a report? Big waves hitting the coast today...
January 10, 2001 (SF Chronicle)
Winter Currents Eroding Beach At Crissy Field/GGNRA showplace
threatened by high tides, surging storm swells
At the Presidios troubled East Beach, those seeking to return Crissy Field to a measure of natural health have been shoveling sand -- and
concrete - - against the tide. And that tides been rising.
This week, four extreme high tides of winter -- 7 feet above the mean -- coupled with high offshore swells surging through the Golden Gate, have sent water lapping near major elements of the $32 million Crissy Field restoration project.
A major storm could compound the threat. The National Weather
Service was predicting cloudy skies and rain this afternoon with the added attraction of brisk wind.
At risk are Crissy Fields broad new promenade, the seat wall that both protects it and offers rest benches for pedestrians and stability of a tidal inlet that leads to the projects centerpiece: a 20-acre marsh and
Already severely eroded is East Beach, a famed windsurfing site that has hosted four national championships. Formerly, its broad, sandy expanse in full view of the Golden Gate Bridge formed an ideal launch zone for
But after the new lagoon was created and tides began to ebb and flow through the inlet, shifts in shoreline current gnawed away at the beach, subtracting sand by the dump truck-load to expose sharp, dangerous rubble
on which beachgoers can cut their feet.
Despite efforts to replenish this sand artificially, it has further eroded. Impacts of winter tides and waves are accelerating this process, and the lovely East Beach now offers a mere bone of its former bulk.
Bill Robberson, president of the 2,000-member San Francisco
Association, walked the beach yesterday morning, and watched waves ride
the extreme high tide. They nibbled within a dozen feet of the
promenade, lapped the base of the footbridge over the inlet, and sucked sand away
from the rocky riprap intended to armor the sides of the inlet channel.
This is what youd expect from a winter tide cycle, said
Robberson, who is also a civil engineer. See how aggressively waves rip at the sand? Imagine if a big storm hit right now. Without the barrier of East Beach,
any extra surge would threaten the seat wall, the promenade and even
the parking lot.
We used to have about 1,100 linear feet of safe, usable beach to
launch and retrieve our boards, Robberson added glumly. Now, were down to about 70 feet, and shrinking.
National Park Service staff of the Golden Gate National Recreation
Area (GGNRA) have been involved in planning and monitoring the Crissy Field restoration, while staff of the park services cooperating nonprofit group, the Golden Gate National Park Association (GGNPA), have funded
and directed the project.
Park Service officials say they share windsurfer worries over East Beach, and promise it will be fixed in the future. For now, they counsel patience. They seek to carefully monitor changes as the beach shoreline
adapts to the new lagoon and inlet, and achieves some sort of natural
stability. Then, take the most logical steps to remedy damage.
The natural cycle is for sand on bay beaches to move offshore
during winter, then come back over summer, said Nancy Hornor, chief of
planning for the park. Our consultant said sand seemed to be accreting at East
Beach last fall. So we hope to see it resume doing that in spring.
Most likely, well do some artificial sand replenishment to speed
things along at the start of the windsurfing season (in March), but during big tides of the storm season, that area is vulnerable, Hornor admitted.
Practical measures taken by the GGNRA-GGNPA thus far include two
sand replenishments, one last spring of about 800 cubic yards, and one last
fall of 2,500 cubic yards. However, both these sand dumps were
eventually nullified by the same erosive forces.
Then, fearing winters onslaught, project managers dug an
8-foot-deep trench alongside the promenade and laid in 220 feet of concrete K-rail,
the movable barriers used on freeways, as an emergency barricade -- at a cost of $50,000.
This last-ditch shield for the promenade has not yet been exposed by tide and wave action. But forecasters note a heavy surf advisory for 19-foot ocean swells predicted to arrive today, stormy weather through Saturday,
and more tall tides into the weekend. That could put this barrier to
Robberson says the long-term test is this: Will the institutional
will and funds be available to restore East Beach after the project gets
transferred to control of the National Park Service in spring? Last
summer, officials said that all $32 million raised for Crissy Field had been spent or assigned.
If we need to take other steps, we will, Hornor said. The East
Beach area is a prime site; its where we have our main entrance and our
parking. If a current budget gets used up, well make another request. Whether its an ongoing need, or some big, specific remedial project, we can make requests through the NPS region, or all the way up to Washington.
E-mail Paul McHugh at email@example.com.
Copyright 2001 SF Chronicle
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