Saturday, December 05, 2009

Camano Island

Behind most of Camano Island's beaches are eroding bluffs that now and then dump sand and gravel onto the back of the beach. Camano's beaches are made of old landslides. But like bluffs all over Puget Sound, every couple hundred feet is owned by someone who loves the beach and the view, but is nervous about their proximity to the edge of the bluff (the very thing that provides them both the beach and the view). Erosion rates are pretty slow on the Sound, however, so most homes won't fall in for centuries, but that is little consolation to someone who had a big chunk collapse last winter.

Seawalls of one form or another can now be found on a third of Puget Sound's beaches and there are many more every year. The effects on our future shoreline of all these walls are going to be very real, but not necessarily immediate and not necessarily the same everywhere. It's too bad we can't bring our great grand kids back from the future to help us explain the problem - they might get more traction than the rest of us!

Narrows Park

I swung by the park early Tuesday morning on the way to Port Orchard. They had just wrapped up the remodel project - the bank has been cleaned up and the logs repositioned. The steel anchors are gone and the concrete wings on the outfall were removed. Together, these should address some of the problems the park had been experiencing the last couple of years.

The underlying issues at Narrows Park are an unfortunate function of the original filling of the stream mouth and the construction of the concrete outfall. Maybe someday there will be a chance to restore a more natural stream mouth. I suspect this would lead to a more sustainable shoreline - albeit a more dynamic one (maybe a small spit, rather than an eroding bank). It would still be a great park and a great beach to visit.

Previous Posts: November, 2008 March, 2006

Saturday, November 28, 2009

Joemma Beach

Joemma Beach State Park is located on the west side of the Key Peninsula, just north of Whiteman Cove. Historically, Whiteman Cove was a large estuary or lagoon separated from Case Inlet by a spit. The spit is now a causeway - the entrance road to Camp Coleman (YMCA) - and the estuarine lagoon is a large lake, except for a very small remnant spit and lagoon at the north end next to the Park. I was last out here in 2000, immediately after the Nisqually Earthquake, noting the sand boils, cracks running through the mud, and slumps in the roadway fill resulting from the shaking (the epicenter was about 10 km southeast and about 30 km down).

What attracted me most to Joemma is the beautiful high bluffs and the long stretch of undeveloped shoreline that lies to the north (see Google Earth map linked to the title of this post). I suspect it is one of the larger remaining chunks of unaltered beach, bluff, and upland forest in South Sound. Unfortunately, the shoreline north of the Park is heavily posted - I guess someone owns this beach. Exploration is clearly discouraged, but sediment movement clearly is not -- the bluffs are dumping sand and gravel on the beach and and the air photos show a wonderful set of spits across the next small estuary to the north.

Mayo Cove

Mayo Cove is on the east side of the Key Peninsula. The village of Lakebay is at the head of the cove. And Bay Lake is just up the valley a little bit.

Penrose Point State Park lies along the southeastern shore of the cove.
The Park consists of lots of forested shoreline - mainly low bluffs, but also several small barrier spits. One of the big draws of the park is "the spit", which really isn't a spit at all, but a slender ridge or bar extending offshore - visible at low tides and probably the seaward extension of one of the glacial ridges. Or at least that's my understanding. It's been years since I've visited here at low tide, and today most of the beach was underwater.

The park has a couple of day use areas. One is a picnic area and a soggy lawn, probably built over a historic wetland. The green of the lawn was matched by the enteromorpha (or ulva?) recently washed up on the beach. Around the corner is a long terrace of fill, held together with an ugly, and aging, timber bulkhead. Makes it easier to walk along the shoreline at high tide - but no more beach! Seems like there might be a compromise.

The other day use area is located on a small spit that sticks out into the bay across from the old Lakebay Marina. It looks like it has an interesting history - there are a series of plank groins - and a plank wall going down the spine of the spit. Sort of looks like someone tried to put the spit in a wooden box. Sort of makes for a strange spit. Seems like it might do perfectly okay on its own, though I suppose if you took out the timber skeleton all at once, the spit might wobble a little before getting its sea legs back.

Key Peninsula

The day after Thanksgiving and the weather report claimed this would be the dryest day of the weekend. The rest of the family had other commitments, so I dropped D in Redmond, filled up my coffee cup, and headed for the Tacoma Narrows and western Pierce County.

The Key Peninsula is the southern extension of the larger Kitsap Peninsula, the convoluted almost-island connected to everything else in the continental U.S. by a narrow strip of land between Belfair and Allyn (and the Tacoma Narrows Bridge). It is home to Vaughn, Longbranch, and Lakebay. It is also home to Home (an ex-Utopian enclave on Van Geldern Cove). Most of its shoreline is hard to get to without a boat or a deed to waterfront property, but there are still some nice beaches accessible to the rest of us. Turned out to be a wonderful afternoon.

Thursday, November 12, 2009

West Point

West Point, the western tip of Discovery Park, is arguably Seattle's finest beach (there are others, but each has a very different character). Its north and south beaches converge to form a cuspate foreland that points west from Seattle toward the Olympics. There used to be a tidal lagoon, with an inlet on the north side of the point, where the big treatment plant now sits.

Every beach has a story, or two, but this one has many. Native American history, earthquakes and landslides, tsunamis and subsidence, and the punctuated evolution of a coastal landform. The military showed up and created Fort Lawton, then Seattle showed up with the treatment plant. In 1980, a large sewage lagoon on the south beach was removed along with its enclosing riprap and the beach was nourished with a few tens of thousands of yards of sand and gravel and planted with lots of dune grass. Today, walking the south beach, you might never know any of this (if you ignore the hum in the background of Seattle's waste stream being digested).

I rode my bike down from the park on top (you need a permit to park a car down here) and walked south as far as I could go with today's tide, since the east end of the beach is marked by a large promontory of Pleistocene sediments that have managed somehow to resist the waves and stand like a prow to mid-tide. This is highly unusual on the Sound - suggesting an incredibly durable lithology and/or a more complicated story (which is usually the case, isn't it?)

This place deserves a return trip at a lower tide and with more hours left in the day.

By the way, the instrument tower at the point is a good place to check for wind conditions on the Sound:
Station WPOW1 : West Point

As of this little addendum on Monday evening (11-16-09), air pressure is dropping with another storm coming in -- high winds anticipated

Saturday, October 31, 2009

Weaverling Spit

For decades, this beach on the north side of Weaverling Spit has been eroding back into the fill that was placed around the original railroad grade (now the Tommy Thompson bike trail). Pulling back the fill would probably have solved the erosion problem, but would have been hard to sell to the various parties involved. But building a seawall or dumping rock is also hard to sell these days and would have done nothing to restore the beach itself, so folks got together to develop a softer solution.

This nourishment project was completed last month and it seems like a good approach for this site. Sand and gravel was placed on the upper beach, old rock and concrete debris was either carted away or buried, and four anchored log groins (we euphemistically call low groins "drift sills" here - a Wolf Bauer term) were built, although I am not really convinced they are necessary. They add complexity, hard structure, and cost to what might have been a simpler project, but there are also good reasons for including them on some projects.

It will be fun to watch this site evolve - even just over the next few months. Conventional armoring goes in and not much happens visually - after all the purpose of a hard structure is to NOT allow change (many
of the impacts of armoring, other than the ones associated with its initial placement, take time to emerge). But nourishment projects are intended to be flexible and like natural beaches, change with storms and seasons. In the process, they tell us much about the factors influencing a site.

Several things will be worth watching. There is already considerable rearrangement of the beach face going on, particularly at the west end where a distinct berm is forming lower on the beach. The stream outfall at the very west end interacts with the new beach and its delta may become a sink for some of the new sediment. There will be some spreading of gravel eastward from the project, although I doubt the volumes will be high. The most important changes will be in the evolution of the berm. Instead of building this project with a natural berm, the sand and gravel were just piled high against the bank. This material will gradually erode and be incorporated into the gravelly foreshore. A berm will slowly develop, allowing logs to accumulate, although logs build up slower on these north-facing shorelines (it's about the wind). The lack of a natural berm and the eroding material from the upper part of the project will keep this from looking like a natural beach for several years, but we should remember that shoreline projects should not be judged over the short-term.

There are some shots from nearby, though not this particular site, at:

Weaverling Spit: September 2009.
And if you want to check out the trail - just note that a fire on the trestle a couple of weeks ago closed the trail east across Fidalgo Bay from Weaverling.

Sunday, October 04, 2009

Whatcom Waterway

Whatcom Creek flows through Bellingham and tumbles down rocky ledges to meet tidewater. I suppose it once flowed from there through a small estuary and then out across a broad intertidal delta into the bay, but now it enters the head of the straightened and dredged waterway and flows through the old Georgia Pacific site before reaching deep water. The mill itself was built on fill over the original tideflats. Some of the inner estuary is being restored, but there's not much evidence left of the stream delta or the original shoreline.

A small pocket beach had formed on the inside of the old log pond at the mill site - confirmation that if you have loose sediment, wave action, and a favorable geometry, beaches can form anywhere.
This beach should serve as a useful guide when it comes time to redesign a new shoreline park along here.

New Whatcom

For decades, Bellingham's waterfront was dominated by the Georgia Pacific paper mill, but now the mill has closed and the city has an opportunity to do something new and exciting on its shoreline. But it will take a long time to sort the economics, the priorities, the history, and the toxic residue. Meanwhile, some wonderful decaying industrial architecture remains perched on this huge chunk of shoreline.

Nooksack Delta

The Nooksack River drains a large section of the North Cascades between Mount Baker and Canada and has been carry Cascades dirt into Bellingham Bay for ages. Historically, the Nooksack also drained to Lummi Bay, doing so along the path of what is now the Red River, but that option was foreclosed (a deliberate manipulation) over a hundred years ago. The Nooksack continues to build its delta into the northern part of the Bellingham Bay, with the associated sand flats spreading both east past Marietta (toward Bellingham) and southwest along the Lummi Peninsula. Its delta remains the most natural of all the big river deltas on the eastern shore of the Sound, with multiple, changing distributaries and forested wetlands.

Lummi Shore Drive

Probably the largest and longest erosion control project on Puget Sound in recent years was the construction of this revetment in the late 1990s. The road was too close to the edge of the eroding bluff and sections occasionally caved off - reducing the road to a single lane. Some consideration may have been given to moving the road, but that option didn't get much traction in the face of local interests and funding sources that favor defense rather than avoidance. The road is nice and offers great views across the bay to Bellingham, the Cascades, and Portage and Lummi Islands, but the upper beach is gone forever - although some attempt has been made to maintain it by periodically adding sand and gravel. Unfortunately, that's probably not a terribly sustainable solution over the longer term on a site like this.