Lawson Creek

I visited this shoreline four and a half years ago (also at the end of a long day at the Salish Sea Conference) and made a note to come back at a lower tide. I've been hearing about this project from a number of directions and wanted to see it for myself. I dragged a few other folks along, too.

Previous Post: West Vancouver 2011

West Vancouver's shoreline is subject to highly oblique wave action from the west, which moves whatever sediment is available eastward. Prior to development, most of this material probably ended up stacked against the delta of the Capilano River (under the Lion's Gate Bridge), in a more natural version of today's engineered Ambleside Beach (Ambleside 2011). Now much of it is trapped against groins or other obstructions at Dundarave and Ambleside.

I don't know this area well, but I suspect most of the sediment comes from the streams that flow to the beach off the hills above West Vancouver. And I don't know how that budget has changed with development - is it increased, or is it trapped in detention ponds? The problem is keeping it on the steep foreshore when it gets there.

At Lawson Creek just west of Ambleside, there have been efforts to add large boulders to the beach face in order to retain, or trap, sand and gravel. The result is a beach covered with (almost) randomly placed clusters of rocks. I suppose there were already scattered glacial boulders on the beach, but the result here was one of the weirder beaches I've seen. This approach has also been tried, or is planned, at other West Vancouver creek mouths.

(Now that I've looked at the aerials again, I'm wishing we'd gone a little farther west to see the next creek, where this basic idea has been taken to a another level)

AERIAL VIEW

I admit to being a little skeptical about this approach. It's not that it may not work locally, but it seems like it depends on how much sediment is really available. And whether the volumes are sufficient to make a substantial difference in the profile on these steep, narrow beaches.

Engineers have been proposing placing objects of some sort on the foreshore to trap sediment and prevent erosion forever (only a minor exaggeration). Groins, artificial seagrass, submerged sills and breakwaters, and a whole series of patented concrete devices sold for their promise of building back a beach where one has been lost. They may work, in some places, for a while, but they often do not. When sediment is successfully retained, the consequence can adversely impact down-drift beaches (much as with traditional groins). This may not be an issue here where the beach sediment is already largely confined to the big pockets against the projecting groins and piers.

Ambleside

I may have seen this beach from the Lion's Gate Bridge earlier, but the first time it really registered with me was 20 years ago when I heard Wolf Bauer talk about it.  But this week was the first time I've actually walked it - or watched the sun set from it!


The exposure to waves from the west must drive any loose sediment on the West Vancouver shoreline eastward and historically it probably wound up incorporated into the protruding delta of the Capilano River, which emerges into Burrard Inlet just east of the bridge.  Groins (groynes, in Canadian) now organize West Vancouver's sand and gravel into pocket beaches - including the large one at Ambleside Park.  The beach curves out to meet a large groyne, on the end of which stands a Squamish figure welcoming visitors to Vancouver and the Squamish's historic land.




AERIAL VIEW

Second Beach

Vancouver has many small pocket beaches that face westward out into the bay and I've probably posted from most of them by now (a few links below). Second Beach, in Stanley Park is yet another of these. Like the others, it has been enhanced by the construction of structures that help maintain the pocket and also probably by the addition of sediment at some point.

AERIAL VIEW

Second Beach lies just east of the big pool (frozen over on this trip) which looks as if it was probably constructed out over the foreshore. This improves the configuration of the shoreline for the beach itself. There's also a rock groin at the east end which keeps Second Beach from spilling around the corner and joining the much larger, but similarly aligned, First Beach (but which is usually called English Bay Beach).

English Bay: December 2014
Third Beach: April 2007
Sunset Beach: August 2016
Kitsilano: April 2016
Jericho Beach: August 2008
Ambleside: October 2011

The Stanley Park seawall west of the Second Beach pool

Kitsilano Beach

Most of Vancouver's shorelines are oriented obliquely to the large western fetch across Georgia Strait, which means that beaches (natural or constructed) tend to do best when the orientation of shoreline allows west-facing swash aligned beaches to form. This is best seen by looking at aerial views of West Vancouver, Third Beach in Stanley Park, English Bay, and Kitsilano.

AERIAL VIEW

The main beach at Kitsilano, on the south side of English Bay, is controlled by a bouldery headland that makes the swash-aligned beach possible. I suspect sediment has been added periodically to maintain the broad recreational beach, but other than a couple of small rock groins, this beach doesn't depend on larger groins like we've seen at Ambleside or on the north shore of English Bay.

There's a second beach at Kitsilano, just around the corner northeast of the main beach. But it appears to have been created by the construction of a rock jetty at the entrance to False Creek (see aerial). It's oriented a little differently than the main beach, suggesting (to me, at least) that waves may refract around the headland between the beaches and approach this one at a slightly sharper angle.

I've always been intrigued by these rippled patterns on Salish Sea beaches. They're often pretty subtle, but they raise questions about their formation. These are not the same as ripples you might see in other types of beach environments. They typically form perpendicular to the beach and may extend through a significant tidal range. They tend to have wavelengths of 30-60 cms, but sometimes more. It seems like they would have to form on a falling tide to be preserved. But once the pattern is established at high tide, it is propagated down the beach as the tide falls. They may be somehow related to larger scale horns and cusps on other beaches, where the emergent bedform influences subsequent swash patterns, further reinforcing the original undulations. If that makes any sense at all! This phenomenon is probably well documented by others, but I've never seen it described. There is an abundant literature on cusps (still controversial) and on ripples, but I think this is something a little different. Or maybe in between.

Wolf Bauer

West Point 2004

Golden Gardens 2011

Seacrest 2011

Brackett's Landing 2009

Ambleside 2011

Tolmie 2009

West Point 2010

Birch Bay 2010 

24 February 2012

Wolf,

As you begin your second century, I wanted to remind you of what an amazing difference you have made for Puget Sound shorelines and for the people who visit them.

You were instrumental in raising awareness of shorelines and in creating a demand for shoreline protection.  Today, it’s easy to take our beautiful beaches for granted, but without the amazing efforts of you and others in the early 1970s, this place would be a very unattractive place.  Your language and your ideas have remained lasting elements of Shoreline Master Programs across the state.

You described accretion beaches as an endangered species.  At the time, you may have doubted our progress, and it’s true that we have lost some special places.  But thanks to your work, many remain intact and more are becoming public.  Lily Point on Point Roberts is now a county park.

In the 1980s you spoke adamantly of the need to restore our urban beaches and to enhance the public’s shoreline experience.  But you did not just talk about it, you gave us examples.  Today, we have examples everywhere: in Seattle, Tacoma, Bremerton, and elsewhere.  And there are a new generation of projects such as the Sculpture Park Beach in Seattle and Marine Park in Fairhaven that were inspired by your example and carried out by impassioned individuals who had learned from you.

People enjoy our most spectacular urban beaches, yet many do not realize that these places were once buried in riprap and would be still were it not for your efforts.  People love the beaches at Discovery Park, Golden Gardens, Birch Bay, West Vancouver, and Tolmie State Park.  They think these places have always been this nice!

This year, we are mapping feeder bluffs throughout the Sound – the feeder bluffs that you taught us were such a critical element of the shore-process corridor.  Also this year, I was approached about what to do about salt marshes choked with cut logs from decades of sloppy log-rafting practices.  I jumped at the chance to share your presentation on this subject from almost two decades ago.

Increasingly, parks managers and and government regulators and fish biologists are looking for opportunities to restore beaches and to put sediment back into the system, not lock it away behind walls of rock.  People still build bulkheads, but doing so is widely discouraged and is increasingly difficult. In some places we are actually pulling seawalls off the beach and removing riprap from our spits.

Your legacy runs deep on Puget Sound and our shorelines are far, far better places today than they ever would have been without your incredible passion and your tireless commitment.

Thank you,

Hugh

NOTE:  Wolf turned 100 on February 24th. These photos, most taken recently, are all nourished beaches designed by Wolf in the 1970s and 1980s. Their captions link (in most cases) to previous posts on those places. Previous Gravel Beach posts mentioning Wolf can be found at:  Bauer Posts.

West Vancouver

There is a public promenade along the shoreline all the way from Dundarave to Ambleside (2-3 kms), most of it heavily armored to protect it from storm waves.  The high tide prevented me from getting much of a sense of the intertidal, but it appears that the orientation, and perhaps severely limited sediment availability, results in little opportunity for real beaches except where projecting structures act as groins.


The West Vancouver Shoreline Preservation Society has been experimenting with using strategically placed rock to act as reefs to enhance habitat and to help trap sediment in the intertidal.  They have also been working to improve stream mouths and stormwater outfalls along this heavily urbanized shoreline.  I'll have to come back at a low tide sometime and take a closer look.


AERIAL VIEW