Monday, January 23, 2017

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.

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

Stearman Beach

Much of West Vancouver's western shoreline has a bedrock foundation, with scattered beaches where favored by shoreline configuration and stream mouths. Stearman Beach is at one of these stream mouths. It and other nearby streams (Cypress Creek, just east, is considerably larger) have built small deltas and a broad gravelly foreshore, which provides sediment and elevation for the beaches (albeit small and irregular beaches).


The homes that look out over Stearman Beach are relatively modest, at least compared to many of the others along West Vancouver's shoreline. The ones here all have glass railings - providing for views while discouraging the curious from clambering over their seawalls.


I posted from here back in October 2011 and then again just this past year, in April 2016. I like the broad western view out into the Strait of Georgia, always dotted with large ships waiting to pick up Canadian stuff to take to Asia (or at least I think that's what they're doing) and the east view back towards Vancouver and Stanley Park.


But mainly I like the two contrasting beaches on each side of the jetty. The simple gravel pocket beach built up against the west side and the wonderful little sand-on-the-steps beach on the lee side.

Sunday, January 22, 2017

Bayview State Park

Bayview is just down the road from the Padilla Bay Reserve and an easy place to check out during a short lunch break. Although I knew there was work planned here, I was never clear just what was going to be done - or even just what problem was to be solved. Not that this site hasn't had problems - the inevitable consequence of it's artificial creation many decades ago, it's rectangular footprint, and it's unnatural projection out into the bay.


Here's a post from a few years ago - Bayview: January 2012 - which may provide some hints as to the recent work. Previously, two terminal groins and two intermediate groins maintained a nourished beach on the western edge of this rectangular pad of historic fill.

The new project has removed the intermediate groins, enlarged the terminal groins, and added a lot of gravel. The beach at the south end of the site, which never amounted to much, has been significantly enhanced with gravel and logs. And the backshore has been improved with plantings and some effort to manage beach access points.

Overall, it looks pretty good. The end corners, where much extra sediment was placed, will continue to adjust -- and I suspect the additional material was placed with this in mind. We'll keep watching.


Marine Park lies just south of the Peace Arch in Blaine. I posted from here in January 2010 and again in April 2016. The peninsula on which the wharf district is built was created largely (entirely?) from dredged material (though probably of different vintages). The outer (northwestern) edge had been armored with rock and concrete and a variety of old debris, resulting in nice views, but an ugly shoreline where access to the water can be hazardous.

The one exception was a small beach that had formed where the ragged edge of the peninsula happened to offer an appropriate configuration. But this actually provides a very nice template for future work - since it shows what orientation, what sediment size, and what beach and berm profile works best. The best model for a created beach is the beach next door!


A couple of years ago the city began resculpting the edge and created a pocket beach. They improved the rock work at a couple of small promontories, excavated the rock and fill between them, and added gravel. Orientation is key on these pocket beaches and this one may still be adjusting. The mobile sand and gravel is wanting to stay in the northeastern half of the little cove, leaving the western end a steeper slope of coarse cobble and rock, but it looks like overall the project has worked out well.

This project was limited to just one segment of shoreline, but it sounds like there's interest in extending this approach to additional segments in the future. You still need rocky hard points to anchor and contain the beaches, but the rock need not be old construction debris. And most of the shoreline can be a series of small beaches.

Saturday, January 21, 2017

Semiahmoo Spit

Semiahmoo Spit reaches north across the mouth of Drayton Harbor - with a long narrow neck and a very broad bulb at its distal end. This large expanse was created when the marina was dredged and the dredge "spoil" was used to greatly increase the size and elevation of the spit.


The perimeter of the spit consists of an irregular pattern of modest banks eroded into the dredged material and low depositional segments likely formed by the gradual redistribution of material along the shoreline. That means much of this shoreline is constructed, yet behaves much as a natural beach. And other than at the neck of the spit itself (see below), there's been no need to armor the beach.  

After numerous delays, a new phase of development is occurring on the outer edge of the spit, south of the existing resort. Fortunately, the development maintains a public trail system along the shore and has placed the new buildings fairly far back from the edge. Rather than try to fight the chronic erosion, the designers pulled the abrupt edge landward, creating more beach-like area. I say beach-like, because it's still fairly high and steep compared to a natural upper beach.

It looks great, but bears watching. The underlying reasons some segments of this shoreline were receding have not changed by reducing the height of the bank (any more than armoring an eroding bluff prevents the ongoing erosion of the beach itself). So we may find that the new beach continues to erode, probably as a low scarp. And ironically, by reducing the height of the eroding "bluff" we may have reduced the supply of sediment to the beach, which could result in more rapid erosion.

Again, this bears watching. If erosion continues, this might be a good place to consider a localized feed source - a periodically restocked pile of gravel that can meter out sediment to adjacent shorelines as it erodes.  On the other hand, maybe this won't be necessary. And regardless, kudos to Blaine and the development and their designers for what they've done here. In another era, this would have all been riprap.

Speaking of riprap, the real problem at Semiahmoo is the neck of the spit (aside from the clever idea to build a destination resort on a sand spit). Narrow and low - armored on both sides - the roadway is increasingly a causeway. And increasingly vulnerable - even at today's sea levels. (No pictures this trip - maybe next time). There have been some efforts to rebuild a berm on the inside (low energy, marshy), but they may need to be more ambitious. And the outside may require some serious thinking - maybe a coarse gravel cobble revetment of some sort?  It probably won't be easy or cheap, though maybe throwing some coarse gravel at the south end would be a useful experiment?

Previous posts from Semiahmoo:
Tongue Point: March 2009
Semiahmoo: March 2009

Thursday, January 19, 2017

Birch Bay

The north end of Birch Bay was once a marked by a large complex of spits and marshes. Drift was eastward into the bay, carrying sediment from Birch Point to form a series of spits that terminated in an inlet at the northern corner of the bay. The spits and marshes probably recorded a wonderful chronology of sea level change, geologic events, and early first nations occupation.


In the late 1960s, it all became Birch Bay Village. The wetlands were dredged to create lakes and a marina. The sediment was used to create dry land for homes and golf. A new inlet to the new marina was cut at the base of the spit and the old inlet was left to drain a very small remnant of the original marsh. Drift rapidly built a broad fillet against the west jetty and the downdrift beaches were starved of their natural source of material (though sediment dredged from the inlet is now periodically bypassed to those beaches). Wolf Bauer and Maury Schwartz both used Birch Bay Village as an example of what not to do to beaches.

These pictures were taken at the inlet and near the west end, where the bluff ends and the spit begins. They show the beach west of the inlet, the jetties, the seawalls east of the inlet, and a remarkably large rock buttress on the first bluff property to the west.

Wednesday, January 18, 2017

Gulf Road

A cold, clear day at the southern end of the Strait of Georgia. The wind was blowing out of the Fraser Valley but that meant this section of southwest facing beach was remarkably calm (farther south, Mukilteo and Edmonds were getting hammered by waves).

Gulf Road ends at this wonderful little stretch of beach, just south of Cherry Point. While there are bluffs in the distance in both directions, this section is a barrier beach with a nice back-barrier wetland, fed by two small streams. An old conveyor extends across the beach, dating to some unknown (by me) operation decades ago.

The roadway is eroding - as roadways on beach berms usually do. It would be neat if they could rethink this shoreline a little - maybe remove the road prism from the berm, restore the altered parts of the wetland, and make some simple public improvements - restrooms, some interpretive signage, some trails.

This shoreline reach extends from Point Whitehorn at the north, south to Sandy Point, a large, heavily developed spit that extends south into Lummi Bay. Sediment transport (beach transport, at least, I can't speak for finer grained sediment farther offshore) has always been a little controversial here. South winds are common, but the influence of a very large fetch to the north is significant and may be more important for drift.  I mentioned this in a previous post from Point Whitehorn (March 2015).


There are three major industries along this shoreline -- a refinery (BP) to the north and another refinery (Phillips) and an aluminum plant (Intalco) to the south. The recently proposed Gateway Pacific Terminal, which was set back by the Corps last spring, would have extended offshore just north, between this site and the BP pier in the distance.

Previous post from here:
Gulf Road: March 2010

Sunday, January 08, 2017

Seahurst Park

Last Monday, I dropped M at the airport early, lingered over coffee at the Burien Press, and then drove down the hill to Seahurst Park. Burien got more snow than the rest of us on New Year's, so the road was still pretty icy. The sun wouldn't come over the bluff for an hour or two, so it was dark. The tide was pretty high, so not a lot of beach was showing. And it was cold. I guess it wasn't surprising that it was so quiet.

The beach appears to have naturalized nicely since the project was wrapped up in 2014 (wow - it's already been more than 2 years!). A more distinct berm has built up in front of the wetland in the central portion of the north beach. The logs have distributed themselves more naturally across the berm. The northern stream mouth has continued to rearrange itself, much as the larger stream to the south has always done. The plantings have taken off. And it looks like there's been some sliding on the bluff at the north end of the park.

Previous Post:  Spring 2015


Speaking of the larger stream - the main one that comes down the ravine with the road - the water level in the small wetland/lagoon at it's mouth was very high and was overflowing across the berm in several locations (the stream mouth in the lead photo is the smaller, northern one, not this one). Some of this looked like it might be the function of some human modifications at the primary outlet, where amateur engineers had been practicing building dams. 

Cultural artifact at the north end