Thursday, May 12, 2016

Deception Pass



I see this beach every time I drive across the Deception Pass bridge (southbound, at least). I see this beach in dozens of pictures I've taken from the bridge (for example: Deception Pass: May 2013). I've seen it numerous times from the rocky promontory where West Beach turns the corner and becomes North Beach. But I don't know if I've actually visited this beach since I started working on beaches more than 25 years ago!

So late on a Friday afternoon two weeks ago, I decided I could delay the trip home for an hour or two. It was one of the best decisions I've made in a long time.

AERIAL VIEW



North Beach is the terminus of the West Beach drift cell. Although I suspect much of the sediment that drifts north along the west side of the Whidbey Island is lost offshore to deep water as it rounds the corner, some gets through. Or at least enough has gotten through in the past that the beach has been able to form and even build out, filling indentations in this originally steep and irregular rocky shoreline. This is a complex area, with strong currents and deep water just offshore, which undoubtedly confuses any simple picture of this beach's behavior. 

There's a neat animation of the West Beach drift cell at the new Shore Friendly website:
Shore Friendly: West Whidbey
(it's worth checking out the rest of the website, too)


I'm often asked about my favorite beach on the Salish Sea. I always struggle with this question (it's sort of like asking me my favorite color or my favorite restaurant), but as soon as I walked down the trail I realized I'd found an answer to that question. It may not be my only favorite beach, but it's the perfect answer the next time I'm asked. It's got everything - rocky headlands, beaches, an undeveloped backshore, fast-moving water, big trees, public ownership, an easy trail, and a beautiful bridge.


Macs Cove - the eastern end of North Beach







Oak Harbor


The low area that connects most of Oak Harbor to Forbes and Maylor Points may have begun as a tombolo - with a low beach connecting the higher ground at both ends. I don't know what its pre-war history, but during World War II the Navy filled much of this area to create a large seaplane base out of which they flew PBY Catalinas.

AERIAL VIEW

Oak Harbor's shoreline configuration seems like it lends itself to beaches (heck, that's what used to be here). There are already some nice ones on the west side of town. Maybe there are also some opportunities here at the east end to enhance beaches in front of the riprap (or replace the riprap with beaches), including this section around the marina. The wave energy is low, so the size of the sediment would be fairly small (so it can still move). I could picture a high tide beach much of the way from downtown around to Maylor Point, where the Navy has already done some beach restoration work in the last few years (a future visit, a future post). With any luck, other folks are already planning this!



Wednesday, May 11, 2016

Maynard's Beach


Two weeks ago, I got a chance to revisit this restoration site on Discovery Bay (Previous post: Maynard's Lagoon: January 2015). It's right off of U.S. 101, just past the old railroad cars where, at least in the past, you could get an ice cream cone on the way back from the Peninsula. This is actually just one of several recent restoration projects at the head of the bay - all carried out by NOSC.

The configuration of the site was largely shaped by the railroad and the old mill. The mill is all gone, as are the tracks, but the railroad grade itself now helps create a series of lagoons (pocket estuaries, as we often call them here). The result is a fairly natural interpretation of a largely artificial shoreline.

In my earlier post, I had suggested that the tracks might have followed a longer spit across the mouth of the main lagoon, but I realize that the remnant spit at the northeast end of the lagoon (on the bayside of the railroad causeway) is probably all there was.

AERIAL VIEW

There's not much wave action here and it may take a while for the beach to sort itself out, but the vegetation is beginning to take off. A large portion of the beach is already sprouting new salicornia (pickle weed), foreshadowing its future as a marsh as much as a beach. This site has a little of everything - a low energy beach, fringing marshes, a stream, multiple lagoons, and upland forest. It will be fun to watch it evolve in the coming years.



Salsbury Point


In the fall of 1995, Kitsap County Parks removed the old riprap and nourished the beach. And it's still doing remarkably well.

It's a difficult site - the lagoon was filled, the beach pushed out, and the coastal regime altered because of the boat ramps and because the floating bridge has cut off much of the southerly wave action (which would have continued to deliver sediment). The original plan was just to rebuild a nicer rock bulkhead, but a habitat biologist pushed back, suggesting something softer. And County Parks staff were willing to listen. A geologist with the state (much younger then) helped them sketch out some ideas and cross-sections, based on experience with some of Wolf Bauer's designs.

Beach east of the boat ramps
Although I was pretty confident the project would work, I never would have expected it to go 20 years without a little assistance. The underlying erosion problem remains and the beach has gradually retreated into the backshore created in 1995. The backshore is a little too high, so it doesn't get overtopped, and therefore supports upland vegetation better than beach grass. An old drain pipe has gradually been exposed and dribbles rusty water onto the beach.

Healthy beach at south end of park
Previous post:  Salsbury Point: 2013

I think some adaptive management is due. Before someone gets surprised and does something dumb. I understand there is talk of doing some work on the boat ramp(s) - maybe that will be a chance to look at some options.

AERIAL VIEW

Of course, there's still a difficult stretch between the main park and the ramp - I think it's where electric cables head out under the canal. It's oriented obliquely to the waves and has no sediment - which presents a real challenge.



Port Gamble



I posted about the old Port Gamble mill site a couple of years ago (Teekalet 2014) and since then much of that site has been cleaned up - although any significant redevelopment is still down the road.

This post is from the shoreline south of the point, along the western shore of the bay. This area is also getting cleaned up - it used to be piles, log rafts, and other timber industry relics, some of which remains.

This is a fairly protected shoreline of modest bluffs and small stream mouths. It's going to be a very pleasant shoreline to explore as the public access is improved and the remaining debris is removed, although I assume some of the old stuff will stay, either to provide some historic context or because it gets overlooked.

AERIAL VIEW


Maybe I'll come back in the kayak this summer.


Monday, May 09, 2016

Edgewater Beach


Before 2005, this was an out of the way spot where a lot of folks came to run their dogs on the beach. There was a dirt parking lot behind an eroding bank, and a small pocket beach tucked into the corner formed by the eastern end of the old tank farm.

Then the Port of Everett built the Mount Baker Terminal, primarily to move large airplane parts up the hill to Boeing's plant at Paine Field. Mitigation for the pier included improvements to the beach, but until the last year or so it was still sort of hard to get down here. Now the park is open and there were dogs out running on the beach again.

AERIAL VIEW

There are really three parts to this beach. There is the western corner where the beach was before. The orientation doesn't really lend itself to stability and it tends to unravel (just as it did prior to the pier), causing erosion along its back edge and leaving a beach covered with smaller riprap and quarry spalls shed from the adjacent riprap. Sediment eroded from this beach ends up on the low tide terrace, with help from the streams under the pier.

The middle part of the beach is largely under the pier and isn't really a beach, but is actually the delta of the two creeks that emerge from pipes under the base of the pier. The creeks drain two gullies that lead down the hill above the tank farm. The creeks are very effective at redistributing beach sediment from the upper beach down to the low tide terrace, where it's hard to get it back. This appears to be the sink for some of the sediment added on both sides of the pier ten years ago.

The beach farther east stretches out for 1000' along the railroad grade and has done well. It's probably eroded back a little, but there's a nice berm, plenty of logs, and a heavily vegetated backshore where once there was just a towering seawall and no beach at high tide. 

Much of the sediment lost from this beach has simply spread out farther along the train tracks, which is exactly what was hoped for in the first place.

This was an expensive project and we may need some cheaper approaches, but it's an important demonstration of how we might eventually restore a lot more of the Great Northern Beach between Golden Gardens and Everett.




Sunday, May 08, 2016

Mukilteo


Government Pier - the big old fuel pier when this was still a tank farm - came out last year, one of a series of steps to remodel this shoreline on the north side of Point Elliott. The plan in the next few years is to relocate the ferry terminal to this area, with the new dock taking advantage of the deep water right offshore.

AERIAL VIEW

The edge is still pretty ragged. I don't mind the buttress of the old pier, but the riprap is a mess (it could probably be steeper and neater, leaving a much nicer beach) and there's an awful lot of asphalt rubble and old plumbing still left. It's pretty common after a structure on the beach is demolished for old debris to keep reemerging - something to keep after.

(There's another ugly section of shoreline farther west, in front of the NMFS Research Station, but I'll keep my fingers crossed that they have a plan to clean that up someday, too!)

I'm looking forward to this beach in a few years, after the ferry terminal is done. It seems like there is an opportunity to create a wonderful beach experience all the way from the old ferry terminal to Edgewater Beach (next post) - the only place the beach really vanishes is at the new ferry terminal itself, but the designs show some sort of walkway above the riprap and through the building.

Mukilteo Multimodal Project

The offset in the shoreline where the old pier was located will be difficult to navigate on the beach -- at least at higher tides - but with some imaginative design work, I think this segment could be made much better.

For a great view of the old pier, check out this drone video:
Mukilteo Government Pier (Kevin S)



Friday, May 06, 2016

Double Bluff




I've always assumed that Double Bluff gets its name from its configuration which presents two distinct points to ships sailing in or out of Puget Sound. In the past, I've posted from the southeastern point (Double Bluff: 2010) and the northwestern one (Double Bluff: 2008). This time we're back near the west end again.

The lower portion of this bluff is the type-section of the Double Bluff Drift -- which pre-dates the most recent Vashon glaciers by more than 100,000 years. I believe the upper portion is Whidbey formation - interglacial fluvial sediments. The two photos above show a fossil-rich peat layer and some finely-laminated silts and clays.

AERIAL VIEW

A large failure earlier this spring has dumped a huge pile of material across the beach. Although waves have already cut it back tens of feet, a bump will probably remain for many years. This sediment - at least the sand and gravel fraction, is destined to travel north to the beaches of Mutiny Bay.

Twenty years ago on a field trip (led by Don Easterbrook), we talked about a reddish layer about half way up the bluff. The story was that a peat bed had caught fire and oxidized the surrounding sediments, sort of a natural brick kiln. Coal seams and peat beds, ignited by lightning, forest fires, or humans, can sometimes burn for decades.

The recent landslide had scattered brick-like lumps of peat and clay across the beach and some were already beginning their march north.

For another twist on beach sediment derived from fire-baked sediments, check out this post from the eastern side of Wyoming's Big Horn Mountains:
Lake DeSmet: 2013

Wednesday, May 04, 2016

Waterman


The site of the old Waterman Mill on South Whidbey Island is by no means pristine, with it's 400' of creosote bulkhead and scattered metal debris and old tires on the beach, but it lies along a wonderful stretch of bluffs, which otherwise looks much like it did 200 years ago.

It's been acquired by the Whidbey Camano Land Trust and added to their growing list of successes, which include many very special beaches and bluffs around the two islands. Eventually, the old bulkhead will be removed (carefully -- there's a big wet hillside behind it) and this shoreline will blend back into the ones around it.

This shoreline is a reminder that our most natural bluffs are a wonderful mess, with landslides and fallen trees and a beach that can't make up its mind between sand and gravel or between wide and narrow. It's also a reminder that if a third of our beaches are armored, two thirds of them still aren't.

AERIAL VIEW

The photos don't show this, but low tide aerial photos along this longer reach of shoreline hint at mysteries offshore. The platform appears to drop off sharply (and very close to shore) in a few places, perhaps suggesting submarine landslides. Some day we'll have good shallow multibeam sonar or subtidal lidar along our entire coastline and everyone will wonder why we didn't get it twenty years ago!



Thursday, April 21, 2016

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.