Wednesday, January 28, 2015

Blyn Spit


Driving along U.S. 101, most folks have seen this view up Sequim Bay. This is where the Jamestown S'Klallam Tribe is based and in the last few years they have provided some great places to enjoy the scenery. This view, from the tribal center, looks out over Blyn Spit. For years, I have been able to judge the higher tides as I drove past simply by noting how much of the spit was submerged.

This spit, shaped by northerly winds and waves on the southeastern side of the bay, is typical of small spits in relatively low energy areas (see previous post from Maynard's Lagoon on Discovery Bay). The lack of strong winds and wave run-up prevents the berm from growing as high as in more exposed locations. The lack of coarse gravel and perhaps, the lack of large wood (which tends to blow north and often doesn't build up as much as on these north-facing spits), may also contribute to the lower berm.

In this picture, taken at roughly Mean Higher High Water (MHHW), the spit has almost, but not quite overtopped. Many high tides wash over this feature, which probably doesn't rise more than 1-2 feet above MHHW, explaining why salicornia (pickleweed) dominates the berm ridge, not beach grass and other higher elevation backshore plants.

AERIAL VIEW


Someday, I'll head out to Travis Spit, a few miles north at the mouth of the bay, and post some comparison shots to show what a higher energy spit looks like.  For one thing, the berm is considerably higher and only very rarely would be completely submerged.



Maynard's Lagoon



The old railroad followed the edge of Discovery Bay, cutting across the salt marsh at the head of the inlet and isolating some small estuarine lagoons (maybe just one, originally) along the southwestern side of the bay. The old mill (Maynard's, I guess) sat along the railroad, perched on what was probably the original spit. A mill pond was created behind the mill at one end of the lagoon.

The mill had pretty much dismantled itself, but the remnants remained until NOSC (see below) went to work this fall and removed the old structures and much of the old fill. They dropped the elevations to more closely match the geometry of the old spits and they replumbed the small stream mouth and the estuaries.

AERIAL VIEW

This is a fairly sheltered site since it's tough to generate big waves in this corner of Discovery Bay, but there will still be enough energy to gradually rearrange the beach.  But the bigger story will probably be the riparian vegetation and the fringing marsh.

Walking the beach last Tuesday, there were a few pieces of the old timber structures, and the shape of the shoreline still mimics some of the historic fill, but in a few years, the human history will be almost entirely erased. (The photos were all taken the same day - the foggy one in the morning, the others on the way home).

For more about this project, and about the North Olympic Salmon Coalition, check out:

Lower Discovery Bay Estuary Restoration



Wednesday, December 31, 2014

Jericho Beach




This beach has recently been remodeled (Vancouver Parks info) and if I'd had more time and the weather had been more pleasant, I would have checked more of it out. As it was, this was just a short visit on the way out of town after our Vancouver weekend.

Previous post: Jericho Beach, August 2008

Jericho Beach is one of several enhanced beaches (enhanced largely by the addition of shore-perpendicular structures that help capture the westerly waves) along the south shore of English Bay, that include Kitsilano, Jericho, Locarno, and Spanish Banks Beaches.  Sand is supplied from the broad shoals of Spanish Banks to the west, although the original source of this material may be retreat of the bluffs at Point Gray and the Fraser River. Maybe some was barged in, too?


AERIAL VIEW

Jericho Beach was originally the site of a flying boat station and later became a seaplane base for the RCAF. I guess that explains those strange ramps that are used by all the small boat sailing groups who use the park now.


English Bay


I've visited this beach many times, but my only previous post shows the beach under somewhat more crowded conditions (August 2008).  Today, there were no crowds, and no fireworks, but the sun came out in the midst of an otherwise drizzly weekend and made sitting in the bar at the Sylvia Hotel particularly nice.

AERIAL VIEW

All of Vancouver's beaches are turned to the west, since that's where all of Vancouver's wave energy comes from. This is true of the beaches on both the north and south shores of English Bay, as well as those in West Vancouver.  All of these beaches benefit from promontories, groins, or other structures at their eastern ends that facilitate their more beach-friendly orientation.  I suspect most of them also benefit from the periodic addition of sand brought in from elsewhere.  It's not that there wouldn't have been beaches here naturally, but they wouldn't have looked like these.


Third Beach


Beaches often come in series, so I guess it should come as no surprise that there is more than one "Third Beach."  This is the second Third Beach that I've posted about this year, the other being in La Push (February 2014), but I've also posted about this one before (April 2007).

This one is on the western side of Stanley Park, facing out towards the Strait of Georgia. It must get a lot of wave action during storms, but its orientation and the bedrock ledges help keep the sand in place.

We're coming off some pretty high tides and it looks like under the right conditions, this whole beach is under water (I suppose that could be said of most beaches - it's sort of their nature). There were wrack lines pushed back across the berm and right up against the seawall.

AERIAL VIEW


Thursday, November 06, 2014

Don Morse Beach


This is a fairly new beach (2012?), part of a major rehabilitation of this park on the north side of the town of Chelan.  It appears to be a nice example of what happens when a team of landscape architects, waterfront engineers, and shoreline designers come together with a community willing to try something new.

AERIAL VIEW

The beach is constructed of pea gravel organized behind a couple of rock groins that reorient the beach to better take advantage of the westerly waves.  It looked like the beach was still making small adjustments - which is sort of typical for these kinds of projects. And must be an interesting challenge on lakes with substantial swings in water level over the year.

There is a broad sandy backshore, somewhere beneath which is the original bulkhead (or at least that's how I understand it).



Manson


I covered the south side of the lake as far as  I could in the car (25-Mile Creek), before backtracking to town and heading up the northeast side toward (and beyond) Manson, which is a few miles up the lake from Chelan.

Most of this shoreline is bumper to bumper waterfront homes, built out on fill and perched on bulkheads. If there were originally natural beaches at this lake elevation, they would be long buried beneath houses and lawns.


There are a few beaches where the orientation (generally towards the upper end of the lake) and available sediment (native or imported) were favorable, but not many.

AERIAL VIEW

There was a nice little pocket beach in Manson itself (Manson Bay Park), tucked behind a pier/breakwater that shelters it from the waves coming down the lake.  As with the other sites, I'd like to see this in the winter when the lake level is lower.



Lakeside Park




Lakeside Park is located on a point on the south side of the lake near town.  It's got a nice swash-aligned beach facing right up the lake on its western shore, It's not completely swash-aligned, as the beach seems to be trying to leak northward past the ramps and the dock and the rock groin at the tip of the point.

The north-facing shoreline is more complicated.  There's a broad beach with a backshore wallow (that's probably not how it's advertised) - maybe a warm water pool for kids to play in during the summer?

AERIAL VIEW




The foreshore immediately east of the rock groin at the point is bare of sediment (except for a narrow gravel bar) suggesting that wind waves coming down the lake tend to move sediment towards town.  This also fits with the very steep submerged edge of the fine gravel beach at the east end, where it appears to be spilling off into deeper water.  I guess it would look different during lower lake lake levels later in the year.


Lake Chelan State Park



This is the first of several posts from a Sunday spent exploring the lower end of Lake Chelan two weeks ago.  It was nice to have a pleasant day to explore without having to compete with summertime traffic and the background buzz of jet skis.

Lake Chelan reminded me that I have a lot to learn about constructed beaches on lakes with managed water levels. Which I've come to realize are common aspects of developed, recreational lakes, not exceptions.

The lake level has been managed since the late 1800s (the modern dam was built in 1927, but apparently the first couple each blew out immediately) and its modern level is somewhat higher than its original level - on average - since both historic and modern varied/vary a lot with runoff. Currently, the Chelan PUD, which manages the dam, keeps the water level within a 20' range - and within a much narrower range in the summer when waterfront property owners and boaters demand both depth and predictability.  I believe the water level during these shots is a few feet lower than the normal summer level (just short of 1100' above sea level), as best as I can tell.

Not surprisingly, there was once a glacier in this trough. The result is a very deep lake (almost 1500', which means it extends below sea level) - and I suppose it competes with Hood Canal as the state's best fjord.  The longest lake in Washington drains via the shortest river in the state, which plunges four hundred feet over four miles to meet the Columbia (Lake Entiat, behind Rocky Reach Dam). Or it would plunge, were not the entire flow bypassed down to the powerhouse via pipes - which makes the Chelan River not only the shortest river in Washington, but also the driest?

AERIAL VIEW

Lake Chelan State Park is on the southwest shore.  The swimming beach is convex waterward and is exposed to waves from multiple directions, but perhaps it's sheltered position from down-lake winds provides some stability. I suspect - but don't know for sure - that this beach may be periodically replenished, or at least scraped back together now and then.

The sign indicated that the beach was built in 1975. I suspect this refers to the basic architecture of the shoreline, which is backed by grassy terraces separated by retaining walls, but maybe it also refers to the beach itself?



Saturday, October 11, 2014

Elwha Delta




The Elwha Delta continues to build outward in step with the delivery of sediment from the reservoirs behind the Elwha and Glines Canyon Dams. Both dams are gone, the river is running freely, and an amazing amount of sand has made it to the river mouth, although there is a lot more still to come. 

Gravel is beginning to appear on the new bars and spits at the river mouth, although I suspect it will take repeated cycles of river mouth movement and wave action to recycle and sort this material before more persistent coarse-grained features can form.

For a more thorough update on what's been going on, you might start with Ian's most recent post on the Elwha and then move backwards:
Coast Nerd Gazette: September 2014


One of the most interesting questions, at least to me, is how growth of the delta will eventually contribute to transport of gravel farther down the coast towards Port Angeles. This probably isn't a slow dribbling of material to downdrift beaches, but rather it may be driven by events that release larger plugs of material - a shift in the river mouth, a big storm, the growth of a new spit on the east side - who knows?  I'm glad folks are watching.

Previous posts on Gravel Beach:
Elwha Delta (October 2010)
Elwha Delta (March 2013)
Elwha Delta (July 2013)

There's a lot of great material online about the Elwha and the changes occurring on the coast. Besides The Coast Nerd Gazette, check the National Park Service, and the Coastal Watershed Institute. Lynda Mapes has written Elwha: A River Reborn and there is a documentary film, Return of the River out as well.