Summary of Community Comments and Feedback
October 27, 2006
Thanks for another informative update.
I am especially interested in your innovative RFID Gravel Tracer information. The observed variations in gravel migration (up or down beach slopes) by gravel size does not surprise me, since it is consistent with the “natural beach gravel” distribution by size. I think that I can also rationalize the mechanics of non-storm, local winds & tides that result in the opposite gravel migration alongshore observed at the two sites.
Sediment migration along Point White Drive beaches that can result (and has resulted) from a single major storm is much greater, & many times more rapid, than your test gravel tracer results to date. For example, a single strong southwesterly wind storm a few years ago moved a significant amount of gravel & shells up slope at the Bennett site and at adjacent sites immediately NE of our home. While our beach profile has changed a lot since that storm, both eroding & building, the gravel build-up along the bulkheads to our immediate NE has remained relatively constant over a few full annual cycles. I have observed this by the constant amount of light weight shells found at & even over those bulkheads.
The shoreline is relatively straight between Kane & Bennett sites. However, there is a small point of land, closer the Bennett site that disrupts the otherwise linear bulkhead line. Small as it is, especially at higher tide levels, it does protect the Bennett beach somewhat from the full brunt of our predominantly southerly winds & it may somewhat shield the Kane beach from much less frequent & usually less strong northerly winds.
Inference … net gravel migrationdue to winds moves to the NE at both Bennett & Kane sites, more strongly at Kane than at Bennett.
Flood tides are very strong alongshore to the SW at both sites. Due to a large ebbing back eddy (extending from Lynwood Bay to between the Bennett & Kane sites), ebb tide currents alongshore are quite different at the two test sites. Usually, the SW end of the ebbing back eddy is very near the small point of land mentioned in the Winds comments above. At the Kane site, ebb tide currents along the beach are relatively strong to the NE. However, due to the back eddy, ebb tide currents at the Bennett site (and for many sites to its NE) are much weaker & usually to the SW.
Inference … net gravel migration due to tides at the Bennett site moves to the SW. At the Kane site, tidal action is more equal in both directions, with a possible small migration bias to the SW.
Overall inference during non-storm conditions …
Net gravel migration at the Bennett site is to the SW, more strongly influenced by tidal action than by wind.
Net gravel migration at the Kane site is to the NE, more strongly influenced by winds than by tides.
There seems to be some kind of a mis-labeling of sites between the pictures & charts in the Oct ’06 update. In the satellite picture, the Bennett site is identified as “Group 1”, while in the migration data chart, it is shown as “Group 3”.
On another subject, would/will Spirit have its “hull modifications” accomplished before this winter’s “proposed economic study”? What remaining issues must be resolved to progress from “proposed” to “planned” for that portion of your study?
I hope that these observations are in some way helpful to your overall study objectives.
Don Bennett, Point White, Bainbridge Island
August 16, 2006
Why haven't you folks looked at ground effect vehicles like in use on the English channel and the north sea? One of these could navigate the Richpassage at 80+mph with no wake or problems with floating debris giving about 15 minute passage Bremerton to Seattle.
July 31, 2006
Thanks for your detailed response. I was pretty certain many of my thoughts might have already been addressed, but just wanted to be sure. I particularly appreciate how quickly and professionally you responded.
I estimate in the thirties, my grandfather hand built the concrete saltwater tidal swimming pool which projects prominently to the median tidal region between our property lines. Until the mid fifties, half the neighborhood bulkheads to the SW were exclusively creosoted pilings except for what is now the F Kitchell's residence which had a concrete pool enclosure borderng the beach at extreme high tide. The remainder were natural berm fronting mostly undeveloped properties. The shoreline of the three properties to the east of ours were unimproved and conformed to the existing natural berm which continues to Restoration Point on Country Club of Seattle land.
To the best of my recollection, and the neighbors can verify since I was mostly away pursuing a naval career, the following may be of historical interest.
In the mid 50's John Hauberg purchased the unimproved lot bordering our western property line and built the existing 300' concrete bulkhead including an oblique concrete projection extending below mean high tide. In the following years, each of the neighbors in turn replaced their bulkheads with renforced concrete or rock. John Hauberg's bulkhead caused immediate sediment erosion and his architects responded with concrete groins extending diagonally well below mean high tide levels and intended to collect and retain sediment. They really had almost no effect.. Later, the neighbors on the SW side of us also installed concrete groins as their new concrete bulkhead seemed to be causing their beach to migrate elsewhere. It was also essentially a failure for the remaining years, neither promoting nor hindering progressive transport.
Then came last February 4th's storm of sustained high winds combined with very high tides. This combination has occurred only a few times in the past century but not with this sustained intensity.
If you or one of your analysts has not walked the beach along Bean's Bight, I would be happy to meet with one of you the next time you visit Bainbridge and show you the incredible erosion which laid bare 5-20 feet of natural berm above extreme high tide for nearly a quarter mile and totally evacuated thousands of sq ft of the former sediment, leaving broken clay "hardpan" as we have always called it.
One of your previous respondents, Marion Docter, is my father's sister. She lives nine properties further SW on Bean's Bight and can provide detailed memories of the neighborhood and the larger storms back to the thirties.
John Nute, Bean's Bight Road
July 31, 2006
Since the last days of the Port Blakely Mill operations, our neighborhood's waterfront properties have endured both natural and human-effected changes in shoreline and beach contour; sediment composition, volume and distribution; marine vegetation; and marine animal life.
I have intermittantly observed the winter storm and vessel wake effects along the shore between Restoration Point and Tow Jam Hill on Bainbridge for more than fifty years. I watched as unrestricted commercial kelp cutters eliminated wake dampening kelp beds and commercial geoduck dredgers blew out and redistributed subtidal sandbars and mud flats which killed off clam, mussel, barnacle, and oyster habitat which in small ways seemed to affect the sediment features along the beach.
With the exception of the low, clay berm shoreline owned by The Country Club of Seattle, nearly all the rest of the southeastern shoreline has been modified above the mean high tide mark by construction of retaining bulkheads of log pilings, reinforced concrete or heavy rock bulkheads, groins, and other forms of armoring, diverting and retaining structures over the past 50 years.
I think I have reviewed all the information available at your website ( http://www.pugetsoundfastferry.com/Home.htm ) regarding the POFF Study and I have a few observations and suggestions:
1. If you have not already done so since the unusually destructive shoreline storm of Feb 04, 2006, I suggest a physical, in situ revisit and affirmation of your previous observations and baseline measurements. I have attached a sample quicktime video clip (.mov file) from that storm and have several others too large to email, if anyone is interested. The significance of this event in my opinion was the large scale sediment transport and redistribution ranging from above extreme high tide to below extreme low tide marks. While the heavy land erosion (up to 20+ feet in some local berm areas above/beyond EHT) and transport of intertidal rocks weighing 40 lb or more were immediately apparent, the transport of the sizes of sediment your study seems to be concentrating on continues today toward some future steady-state condition due to tide, currents, wakes and wind waves across a considerably recontoured submarine landscape. Beginning an instrumented study before steady state is nearly achieved may yield misleading results. The visible results of this redistribution extends nearly a mile in our locale and suggests your targeted beach observation sites may be too narrowly determined without the context of the entire exposed adjacent shoreline. Additionally, the sites you have chosen are along straight vessel legs and no information seems to be forthcoming where ferry heading adjustments through Rich Passage may likely impart unique wave mechanics effects to affected, adjacent shorelines nearby.
2. I have thought about your method and means to measure coarse sediment transport and suggest, if you haven't already, that you consider additional sediment features of shape, surface texture, specific weight, density and specific gravity, as these attributes may have considerably more to do with natural and forced transport than porosity, size, etc. In this regard, I suggest that the sediment instrumented with RFID tags be indigenous - lifted from each beach section to be studied - rather than configuring and planting tagged sediment from some other remote source.
3. Your study does not appear to address other environmental issues, most notably noise abatement factors. In the "old days" south-end Bainbridge commuters could rely on the Kalakala's hinged bow doors vibrating during her turns through Rich Passage to wake them in time to make the 6:30 or 7:15 Winslow ferry to Seattle (not a good sound - especially in heavy weather!). But relative to current passenger-only ferries, the design and operation of the POFF currently running between Vashon and downtown Seattle creates a beating drone which carries unabated across 3-5 miles of water and which can be felt painfully in the frontal area of the human skull inside the home long before the sound can actually be detected by one's ears. Of all the passenger-only ferries I have observed over the past 35 years, this is singularly the worst and should be replaced as soon as possible unless operating the engines at suitably separated RPMs will ameliorate the problem. I have attempted to record the uncomfortable sound to no avail, so I shall gladly serve coffee with an aspirin to any authority who visits to feel and hear for him/herself.
4. From the passengers' point of view, any candidate vessel design should be able to handle the long stretch of nearly abeam weather-waves comfortably between Elliott Bay and Rich Passage and at nearly design cruising speeds - if any prolonged stretches at speeds much lower are expected, then maybe you should be looking at shore erosion effects all the way to Restoration Point as well as Manchester and Blake Island if the beach features are sufficiently unique.
5. Finally, I do not readily notice any association between your partners and the Society for Ecological Restoration, Northwest Chapter. Among other reference sites I have encountered, I commend: http://www.sernw.org/ and specifically, a pertinent paper from that organization in 2000 at: http://www.sernw.org/d2d_2005_docs/Workshop_3/Esturine-Shoreline%20Restoration/WDOE%20alt%20shoreline%20protection.pdf
Overall, I agree with most other respondents that you are headed in the right direction and I particularly commend you for involving grad students and their advisers in your efforts.
I hope my comments are helpful and I look forward to following your progress and seeing your results.
John Nute, Bean's Bight Road, Gem of Puget Sound
July 19, 2006
The beach slope perpendicular to our bulkhead on the west end of our property (& extending into the Madigan’s lot) has not yet returned to the expected steepness w/o a fast ferry operation. There also appears to be a lot more sand, & less gravel in that area.
As we have discussed before, there are many parameters that affect beach slopes. The bulkhead contractor who replaced the Madigan’s bulkhead was required to place a significant amount of sand on the Madigan’s beach after the work was completed. I believe that this addition of exotic material to the beach may be a root cause for our unusual beach consistency & profile. A few days ago, I discussed this with Luis when he was doing one of his beach surveys.
Don Bennett, Point White, Bainbridge Island
June 28, 2006
By way of introduction, my parents purchased property at Pleasant Beach when I was a child, shortly after WWII. The family vacationed there until a permanent residence was completed in 1956. I spent many a Summer on the beach observing ferry traffic and in particular "riding" the shortest wavelength, maximum amplitude (stern?) waves characteristic of several now long retired ferries. I always thought that their having been "rebuilt" several times and also re-engined led to a mismatch between optimum hull speed and actual cruising speed, resulting in generating the "fun" waves. So when the complaints about what seemed to be much less energetic waves from the fast passenger ferries surfaced, I began reading the study reports that my parents saved for me.
I have noted that several LARGE rocks at mid-beach are now totally buried. (I several times tried but failed to dig enough to determine size over the years. One for decades had a peak about a foot above the shore gravel.) I several times thought if they could be located, they would provide very specific data on mid-beach build-up at this location.
My dad constructed over a decade or so the rather unusual curved bulkhead above the normal high tide level. (Part of the motivation was to avoid "tip-over" that he had noted occasionally happens to aging strait walls. Part was to provide as it did some dry beach for a campfire even during a Summer highest tide. And a final part was simply esthetic.) Most of the footing was about a foot below the then existing ground level. The wall extended between 5 and 6 feet above the footing. All members of the family have been amazed that sand has now piled to less than 2 feet of the top in some locations!
So the upper beach has very noticeably built up, particularly in the last decade or two.
It is not clear that the angles of both the upper and lower beach remains about the same over half a century, but I have not heard any thought to the contrary.
I have a number of photos I've taken over they years, some I've previously scanned. (More could be scanned if of value.) I'm not sure to what extent there is any interest in any of my memories or photographs. But as a retired physics/chemistry teacher who has a strong fondness for the beach, I am available to assist in a variety of ways if desired.
If not too much trouble, could I be added to the mailing list?
Dave Trapp, Pleasant Beach