Sunday, April 26, 2009

Brackett's Landing North



In the late 1980s, Edmonds fixed up this little pocket beach north of the ferry terminal. With Wolf Bauer's guidance, they improved the rock jetty (groin?) and brought in additional sand and gravel to rebuild the beach. Longshore drift has sort of lost its meaning here in Edmonds, thanks to all the historic modification, but that doesn't mean the shoreline has to be all riprap and seawall.

In the mid-1990s, the old timber seawall behind the beach was destroyed by a storm riding very high water, but the replacement is an elegant sinuous structure that marks the back of the beach and keeps logs out of the parking lot during high tides. The parks in Edmonds are full of little surprises - public art, engraved quotations, textured concrete, and frequent reminders of maritime connections.

Edmonds






Edmonds was once a large barrier beach built across the western side of a much larger Union Marsh, but a history of saw mills, railroads, tank farms, and a large marina has left little of the original spit or of the original marsh. The streams have been put in pipes - although there is talk of freeing one.
But this central section, between the ferry and the marina, is a wonderful urban beach and a testament to creativity in public access. Over the past two decades, the City has done a great job of turning what might have been walled-off private shoreline into a community resource.

Kitsap Bluffs


The northern Kitsap Peninsula is a reminder of the diversity of Puget Sound's coastline. Most of the shore consists of bluffs built of glacial and other late Pleistocene sediments, but variation in the geologic details, the topography, the exposure, and the nature of the beach make simple generalizations tough.

We covered a lot of shoreline and I've included several different locations in this single post - the bold heading links to a map.
Foulweather Bluff. These high bluffs at the northern tip of the Kitsap Peninsula feed sediment southward to form an elegant spit on hood Canal on the west side and the extensive barriers at Skunk Bay, Hansville, Point No Point on the east. The highest bluffs were riprapped ages ago. The eastern tip of Foulweather Bluff is lower, but unbulkheaded. It is eroding impressively - though any homes are well back (measured in many centuries) from the edge. At least there's still some sediment feeding the beaches to the east.




Kingston. Parts of the shoreline north of Kingston were the site of big deep-seated landslides in the 1970s (and probably every few decades for millennia before that - we just didn't notice).








North of Apple Cove Point. Apple Cove Point itself is a barrier sporting many large homes at sea level (20th century sea level, that is), but the bluffs to the north of it are the kind of mess only a geologist can appreciate. Very large landslides in the late 1990s impacted several proposed building sites - better the slopes failed before the homes were built than after!







Indianola to Point Jefferson. Beautiful south-facing bluffs, though lots of variety between the high bluffs in Indianola and the lower till bluffs east of Doe Kag Wats (the beautiful barrier estuary in the middle of this reach).











Seabold. These bluffs on the northwest side of Bainbridge are among the few stretches of high bluff on the island not buttressed in rock. Classic Puget Sound bluffs - heavily forested, slow but not negligible erosion, subject to shallow slides and occasional larger slumps, and lined with big houses and nervous property owners. But the beaches are what they are supposed to be - lots of sediment, lots of wood, looking like a shoreline, not a canal. Too bad many people's view of the shoreline environment is a view, not the environment. The trees go down and the seawalls go up.



Brownsville. Really large landslides on Puget Sound are unusual. This one occurred around 1980 and is now marked by a monolithic forest of 28-year old alder. Large snags still protrude from the beach far out from the pre-slide shoreline and there is an awful lot of sand in front of this highly unstable stretch of shoreline. Other big landslides like this one include Woodway (Edmonds), Possession (South Whidbey), and Lone Rock (Seabeck). These differ from the large, slow moving, deep-seated slides of which we have so many, but which aren't quite so catastrophic.


Point Bolin. When I visited this site two years ago, I remarked on the unusual concrete pipe bulkhead (Point Bolin, July, 2006). Since then, folks felt compelled to replace it with something a bit newer, and a lot more generic.

Sunday, April 19, 2009

Yellow Bluff






These impressive bluffs on the southwestern shore of Guemes are readily seen from the San Juan Island ferry. The abundant oxidation of the old sands and gravels leads to their orange/yellow color. There were lots of fresh slides - not sure whether this is always the case, or if this reflects the widespread pattern of recent erosion we have been seeing the last three years (particularly in northern Puget Sound?)

I wish I knew the geologic story better, since there was lots of interesting stuff going on in these bluffs. A thick peat layer was often found collapsed on the beach - and it looked like it had burnt, giving it the look of low grade coal or charcoal. The gravelly layer above the peat - maybe 50' up - contained enormous clasts of other material - suggesting a violent past. I'll do some homework before I come back the next time.

There is a public access just south of here at Kelly Point - where, according to the guy on the beach, landing craft were built during the 1940s. There's lots of old iron scattered around and you can tell the area has a history - another reason to do some homework before the next trip.

Demopolis Marsh






I've long admired this long barrier on the southern shore of Guemes and its large freshwater marsh from afar, but this was the first time I'd ever visited it. In so many situations, this spit would be lined with mega-mansions and No Trespassing signs - but in this case, it is managed by the San Juan Preservation Trust. A great place to watch eagles soaring above the large trees in one direction and oil tankers being piloted along Guemes Channel in the other.

It's a short hike from the ferry dock. Respect the private property along the way - on Guemes, shoreline property owners deserve kudos for their open attitude towards beach walkers - too bad such attitudes don't prevail everywhere!

Clark Point






I lashed my bike to a tree at Young's Park on the east side and walked around Clark Point over to West Beach. This beachwalk offers great views of Sinclair and Cypress Islands.

Although much of the point is comprised of high eroding bluffs, the point is flanked by fringing barriers. The barrier on the east side is now developed - that's where the Resort and the Park are located. But the barrier on the west side was special. This side of the island is sandier, giving rise to a wider backshore and, at least in the past, the opportunity to actually build small dunes. Hard to tell, though, since the dunes and backshore are now a heavily forested terrace extending back a hundred feet or more to the high bluff.
The houses are way back on top - out of sight.

I'm often asked about my favorite beaches on Puget Sound. This has got to be one of them. Maybe it's a good thing it's a little difficult to get to.

Guemes Island






I spent Saturday exploring Guemes by bicycle - and foot. For a small island, it has a wonderful diversity of shoreline and some great beaches. The southeast end is rocky (and harder to access), but the rest of the island is marked by spectacular bluffs and long stretches of accretional beaches. As matter of fact, it is impressive how much of the shoreline is barrier beach - some sort of testament to the rolling topography of the island and the abundance of beach forming sand and gravel (from those spectacular bluffs).

Deer Harbor





The west side of Deer Harbor on Orcas Island is rocky, but the east side collects sandy sediment transported north along the shoreline from eroding bluffs to the south. The sand has built a series of small prograded beaches and quasi-spits in the vicinity of the marina.

The shoreline north of the marina is now part of a local park and a wonderful little community beach. Some historical fill and structures were removed and now there's a nice combination of low energy beach and marsh strung out along several hundred meters of shoreline.

English Camp





English Camp is located on the shores of Garrison Bay, near Roche Harbor on San Juan Island. It was established in the 1860s during efforts to solve the Pig War.

The old blockhouse was built over the bank edge and little has changed since. There's not enough wave action in this sheltered bay to cause much erosion - or even to form much of a beach for that matter. The beach is pretty muddy - wave action is necessary to winnow the fines out of a beach -- and the gravel is stable enough to grow barnacles and rockweed. Salicornia occupies the uppermost beach. The National Park Service has instituted some simple measures to reduce erosion - which generally work because they keep visitors from clambering down the bank.

This site is a little peculiar - the terrace on which the camp is built is too high. I should read some of the geo-archaeology reports done on this site - there was also a long native history prior to the Brits showing up - and find out whether they clarify the historical setting.

Nisqually Delta






The Nisqually Delta might have become a deep-water industrial port had it not been for a groundswell of environmental concern in the 1970s. But the lack of industry does not mean that the delta is okay. Deltas are about rivers spreading their sediment across a broad landscape and about the formation of a complex estuarine system. But then we dike them to create pasture for our cows and to prevent flooding of our valuable farmland (valuable because of the past flooding and the sediments it brought). And then hunters and birders discovered the joys of freshwater waterfowl - and easy access to the wetlands along the tops of the dikes.

At Nisqually, the dikes will be removed soon and tidal processes restored to 750 acres of wetland that still retain some of the 19th century tidal channels. Removal of the dikes means loss of the loop trail - although new paths will still allow access to the restored delta. New dikes will maintain some freshwater areas -- and protect the Refuge headquarters from rising sea level? (I put some additional pictures at hshipman.blogspot.com).

One of the interesting questions that came up recently was the history or purpose of the bench that lies along the saltwater side of much of the main dike - is this an earlier dike or a feature built to allow construction of the dike or a protective berm to protect the main dike from erosion? It represents lots of work, and lots of dirt, and will need to be removed in addition to the main dike to assure that natural drainage is restored to the delta.



Maxwelton





Mackie Park is having a bit of a crisis. A new spit forming updrift (south) and offshore of the current beach, has now extended past the end of the boat ramp and has pretty much starved the park of beach sediment. The spit has also created an interesting lagoon in front of homes to the south that previously had waves breaking on their bulkheads. The air photo on Google Maps is a couple of years old, but it shows the complexity of beaches in this area (click on title of this post).

The boat ramp is being undermined - the beach has dropped significantly on the downdrift side and has even dropped on the updrift side. Compare the
earlier post: Mackie Beach, March 2007. The beach in front of the park itself has also eroded significantly - although it always looked to me like maybe the old rock bulkhead reflected an earlier episode of the same process that is occurring today.

It's interesting to find a shoreline where rapid accretion is occurring - and even more interesting to find one where the accretion is causing problems. But the growth of a spit starves downdrift beaches of sediment just as would a groin or a beach mining operation. Growth of a spit like this may have been a contributing factor in the breaching of another spit (Henny's Spit) in the mid-1990s a few miles north of here near Sunlight Beach.

Glendale Creek






I was in Nashville, checking the news, when I learned of the Whidbey "mudslide" - something related to a failing beaver dam and the community of Glendale. It was easy to find pictures online - a bit harder to actually figure out what happened. This past Monday morning, on the way up to Coupeville to teach a Beach Watchers class, I did some quick reconnaissance.

Water backed up behind Glendale Road, just west of its intersection with Holst Road. It's not unusual for culverts to be too small to deal with high flows on these small creeks, particularly when they jam with mud or debris. Despite attempts to lower water levels with pumps, the road ultimately failed, and much of road fill and all the water headed down the 1 mile of canyon to the beach. Unfortunately, Glendale is built at the mouth of the creek (or more accurately, Glendale is built in the mouth of the creek). The flow coming down the valley was probably too much for the channel through town (rebuilt after the culverts washed out in 1997) and stuff washed down the streeat, into yards and houses, and eventually flowed out over the seawalls at the beach. It sounds like at least folks were warned, so nobody was in the way.

I'm still not quite sure where the beavers fit in. Apparently, they have been busy (as beavers are expected to be) upstream during the last few seasons and had built quite a large reservoir. Was it the failure of this dam that led to the subsequent overtaxing of the Glendale Road culvert? Were the beavers slacking off and not maintaining their dam? Or are the beavers simply convenient culprits? These creeks are subject to periodic gully washers - witness the same watershed (and many other similar ones) on New Years, 1997. And we tend not to leave them enough room. Culverts are sometimes too small. Roads are built in narrow stream valleys, limiting the stream channel's ability to carry large floods. And then, just when the stream wants to spread out at the shoreline, we squeeze it into a narrow ditch so we can build homes on each side. These problems are artifacts of historical development, and they are very difficult to solve, but they are as much a part of the problem as heavy rains and incompetent beavers.