Saturday, August 23, 2014

Centennial Beach

Technically, this post is slightly out of order, since I meant to post it after Beach Grove and they sort of go together. Centennial Beach is just updrift (south) of Beach Grove and is essentially the Canadian extension of Maple Beach on the U.S. side.


Centennial Beach is just the most recent of a series of spits and wetlands that have formed on this northeastern shore of Point Roberts, much of which is encompassed within Boundary Bay Regional Park. The aerial view provides a nice glimpse of the complex geomorphology of this area.

Causeway Beach

Causeway Beach is basically the southern edge of the causeway that serves the Tsawwassen Ferry Terminal. I don't know how much intention went into building this beach, or whether it is just an artifact of the gravel-size material eroding out of the armored fill. Regardless, this beach would not have been here before the terminal was constructed - this was just the wide flats of Roberts Bank.

The beach has an impressive fetch to the south. Its orientation makes it unlikely that it has any significant source of coarse sediment, other than from itself. And it's not a uniform width - it undulates along the south side of the highway - in some places there is a wide backshore (little more than a rough gravel parking lot) and in others it narrows to nothing and the roadway is protected by newer riprap.

Beach Grove

Every year, I end up in Richmond or Tsawwassen early on a Saturday morning in August, prior to catching the ferry over to Salt Spring Island.  And every year, I have a choice of beaches to visit. This year, I went back to Beach Grove (2009) and Centennial Beach (2009).

Beach Grove is built on low land - old spits, marshes, that kind of stuff - on the eastern side of the Tssawwassen-Point Roberts hill (once an island, before claimed by the growing Fraser River delta). It receives beach sediment from Lily Point and Maple Beach to the south, although most of this material probably wound up in the series of spits that form Centennial Beach. Most of Beach Grove's shoreline consists of a narrow foreshore in front of a continuous lone of concrete seawalls. Offshore are the broad tidal flats of Boundary Bay.

Beaches can be narrow for a lot of reasons. In this case, I suppose they include 1) a dearth of coarse sediment from the south, 2) the fact that the community was pretty much built on top of the berm and backshore, and 3) the broad fine-grained flats essentially bury the intertidal beach (the flats intersect the beach face at a very high tidal elevation).

Boulevard Park

This past year, a new beach took shape in Bellingham at Boulevard Park. The park inherited a large area of historic fill on which a log mill once operated. Unattended, fill tends to erode away, and to prevent this the foreshore was covered in riprap and old concrete debris. The lawn was a nice place to listen to a concert or throw a frisbee, but getting to the water was a treacherous walk through a dump.

For many years folks have talked about making this shoreline more friendly, and finally, last year, the city went forward with plans to excavate some of the old fill, reconfigure the edge to complement the incoming waves, and construct a gravel beach. This was the first chance I'd had to visit since it was completed.


Orientation is a key factor on these sites and sometimes the shoreline you're given isn't consistent with a stable pocket beach. In this case, the local designers employed a rock groin at the northeast end and even added a small rock hook at low tide to keep gravel from getting away. I understand there is still considerable offshore aerial transport of the pebble, but it would take a lot of kids throwing a lot of rocks to put a big dent in the local sediment budget.  And the waves will tend to move some of them back - with time.

Now if the city could figure out how to clean up the rest of the debris along this shoreline, this could become the crown jewel of what will ultimately become a wonderful string of pearls along the Bellingham waterfront!

Wednesday, August 06, 2014


This is the western of the two spits that form the entrance to Port Gamble bay.  Point Julia, on the east, was described in the previous post. It's likely that this one was fairly similar, but it's tough to tell, since the mill was built in 1853 and the spit was significantly altered by the time of the 1856 T-sheet.


Development of the mill site involved extensive filling of the back shore and beach areas, probably with dredged material, and then protecting this with walls and whatever rubble was available. Wharves and piles extended farther out to allow deep water access to boats.  The existing shoreline edge is an accident of the historic development and its shape reflects the requirements of handling logs and lumber.

Now, with cleanup and redevelopment planned, there is an opportunity to make adjustments to this hard edge that would result in a more appealing, accessible, environmentally functional, and low maintenance shoreline. This would require thinking about the configuration of the edge - and the relationship of individual segments to wave action. Based on the beaches that already exist between rubble headlands, I suspect one could keep just a few hard segments (hopefully done in something nicer than broken concrete) and enhance pocket beaches between them. Not saying this will happen, just that it would be nice!