DCC UPDATE - JANUARY 2009

Favourable weather conditions over the summer to date have meant the volume of sand on the beach continues to rise steadily.

In the meantime, focus group meetings with key stakeholders continued during December and January, with the final group of meetings with these stakeholders scheduled for mid- February. Ecological studies (fauna and flora) of the area has now been completed.

That report on the area's ecology will be the first of a number of comprehensive reports to be received that will eventually provide the information and data needed for the draft plan for Ocean Beach.

All erosion options in DCC focus

From the Otago Daily Times website
The Dunedin City Council says it is looking at all options as it plans the defence of the city's most popular beaches from erosion caused by pounding Pacific waves. Study of the shape of sands to come A multimillion-dollar extension of the St Clair seawall as far as Lawyers Head, to protect St Kilda and Middle beaches, is among extreme "hard options" council staff say cannot be ruled out, while a host of "soft solutions" each come with their own problems. Council parks and reserves team leader Martin Thompson said yesterday a series of projects aimed at gathering data about the state of the three beaches was either finished, nearing completion or soon to start.
The work began in the months after a dramatic series of storms in 2007 caused significant erosion in the area - repeated when the storms returned last year - and threatened to send parts of Kettle Park crumbling into the sea. The projects launched in response included the work of two University of Otago students, who were conducting a monthly GPS survey, mapping the form and volume of sand on the beaches and how it changed over time. Also planned to start soon was a survey using ground-penetrating radar to locate the edges of the old landfill under Kettle Park, parts of which had been exposed by the severe storms in 2007, Mr Thompson said. The projects tied in with work already completed, including mapping the seafloor offshore from the beaches, ongoing monitoring of rip tides - which influenced erosion "hotspots" - and weather information from automated cameras at St Clair. Mr Thompson said the data would then be used in hydrodynamic computer modelling, mapping the impact of possible solutions - from a seawall extension to simply restocking the area with sand - on the beaches over a 50-year period. Other measures to be modelled included the construction of an offshore artificial reef, to dissipate the power of waves, he said. The modelling was expected to begin once the council established a new project team to co-ordinate the next stages of the work, possibly as soon as June this year, he said.
However, it could take the best part of a year to identify the preferred solutions and prepare a draft report recommending the best options to councillors, he said. The initiatives would then be presented for public consultation, and possibly become the subject of a resource consent hearing, meaning any construction could be several years away, he said. The data collection and modelling work had a budget of $335,000 for this year, but some of the possible solutions could be "quite expensive". Extending the St Clair seawall - considered an unlikely example, but one that could not be ruled out - was likely to cost "tens of millions of dollars" and raise significant aesthetic questions, he warned. "That would be a huge cost and maybe quite a structurally intrusive solution." Smaller "soft solutions", such as continually re-stocking the beaches with dredged sand, would be cheaper and less intrusive, but might mean "sacrificing" some vulnerable parts of the coastline to the sea, he said.

It was too soon to say what the likely measures taken would be, or what the exact cost could rise to. "We are not ruling anything out and we are not ruling anything in."In the meantime, the council had an annual budget of $400,000 to maintain a "holding pattern" of remedial work in the area, but the beaches remained vulnerable to further erosion in another series of big storms, he said. "We are at the mercy of the sea, basically, in terms of what sort of storm events we get . . . "If we get a run of storms again this year, we could be back in a situation where we are getting a lot of erosion."

Study of the shape of sands to come

Otago Daily Times
By Chris Morris on Fri, 16 Jan 2009
Large volumes of sand may have returned to Dunedin's most popular beaches, but the picture being painted by two University of Otago students may soon show if it is here to stay.

The pair, Teresa Konlechner and Charlotte Kidd, are engaged in a GPS survey of St Clair, St Kilda and Middle beaches, which aims to build a three-dimensional digital model showing the shape of sand deposits on the beaches.

The work is the latest in a series of monthly surveys undertaken by students, contracted to the Dunedin City Council, since last year's severe storms caused more erosion problems, stripping sand from the area.

And it's surprisingly tough work - the students cover up to 22km each day while taking up to 4000 measurements in the hot sun, and have survived close encounters with curious locals including, earlier this week, an angry sea lion and her young pup.read the rest of the article here

Kayak Point

Another post from that really cold early morning in mid-December. Kayak Point, like Lowell Point, Cama Beach, Breezy Point, Onamac Point, and several others, is some blend of a recurved spit, cuspate foreland, or, the term I prefer, looped barrier. The beach diverges from the coastline at the barrier's updrift end (always the south, in these examples) and then reconnects with the coastline a mile or so north, gradually merging back with the bluff. They inevitably had some sort of lagoon behind them. At some sites there may have been a tidal inlet. At Kayak Point, the remains of the old ebb tide delta are still visible on the lower beach north of the pier.

The bluffs to the south were dripping with icicles. There are some nice lakebed clays in these bluffs and the chunks that occasionally fall onto the beach in big piles display nice varves (laminations), marking the passing of individual years at the bottom of the big lake before the great glacier arrived from the north. Or at least I think that's the correct order of events.

From a warmer day, back in 2007: Kayak Point

Lowell Point

December was crazy and this was one of two posts from mid-month that got lost somewhere before the holidays and Las Vegas. The predictions were for some of the highest tides of the year around daybreak, so I headed way before dawn to Camano and Port Susan for a brisk and quick - very brisk, very quick - morning trip. As is often the case on these relatively calm, cold mornings, the tide is restrained by the high pressure, so my hope to see the water washing the drift logs off the beach failed to materialize. But what a beautiful morning.

Lowell Point is the low barrier beach at Camano Island State Park (click on title of post to go to Google Maps). A high bluff to the south supplies gravel to beaches from here all the way to Utsalady (including Cama Beach). The waves had tossed up a nice little gravel ridge, marking the morning's high tide. The stormier tides from earlier in the weekend had been higher. The lagoon - or what's left of it - was flooded and frozen. There are differing opinions on whether Lowell Point was an open tidal lagoon before the 1900s - if there was an inlet, it would have probably been down near the boat ramp at the north end.

Overton Beach

Overton Beach is a boat launch way up on the north arm of Lake Mead. At Boulder Beach, the waves were able to build small beaches, but not erode the shoreline itself. Here, the shoreline is steeper and the lake has cut a series of subtle strandlines and one not so subtle scarp. I suppose the height of the bluff reflects both the length of time that the lake remained at that particular level, the magnitude of storms that occurred during that period, and the steepness and erodibility of the shoreline itself. Here, the shoreline is on a pair of projecting ridges that appear to have been built as breakwaters when the marina was created, so they consist of nothing but loose gravel.

Boulder Beach

My challenge during a long weekend in Las Vegas (more pictures at hshipman) with lots of extra time on my hands was to find some beaches. Of course, that usually begins with locating water bodies, which around here narrows the search awfully quickly. The first candidate was at the Mandalay Bay, where the pool offered hope of artificial waves and a simulated beach. But it was closed for the season and the photo over the fence isn't worth posting. The next attempt was at Lake Las Vegas, since the Ritz Carlton advertised a white sand beach, but though we walked the shoreline, there was no beach to be found. Maybe you have to be a registered guest.

Lake Mead, on the other hand, does have beaches, although with the lake falling about 10 feet per year since the late 1990s, they don't have much time to form before being stranded. At Boulder Beach, the lake is retreating down a gradually sloping alluvial fan and given enough time in one place, the waves can form small beaches. These gravel barriers were neat, separating small puddle lagoons from the rest of the Colorado River. Occasionally higher waves would spill over the top of the berm, carrying gravel down the backside to form little overwash fans.

Skookum Wulge

The mouth of Hylebos Creek, which emerges on the northeastern edge of the Puyallup Delta, is a dredged estuarine channel lined with fill and heavy industry. As you move out into the bay, the industry gradually shifts to marinas and eventually to residential development. This is one of few places in the Sound where log rafting has persisted into the 2000s.

Commencement Bay is home to many shoreline cleanup sites, some of which have been cleaned up, some of which are still in progress. Much effort has gone into not just cleaning them up but actually restoring habitat. I actually don't know much about the history of this site - it basically consists of a spit and a back-barrier lagoon. The feature has been here in some form or another for decades. I'm not sure what the original shoreline looked like here, but the large fill south of this site went in since the 1940s and I doubt there would have been a spit in this configuration prior to that. The spit itself seems to have consolidated during the past decade, perhaps as a result of increased wave energy due to removal of log rafts or the addition of additional sediment to the area in association with the clean up work. Another place to do some more homework on.

Brown's Point

This entry stems from a Saturday spent in Federal Way early in December. Brown's Point marks the northern entrance of Tacoma's Commencement Bay and began as a small cuspate foreland spit (cuspate foreland, low point, closed point). The sign suggests that the low backshore was filled by the Lighthouse Service in the 1920s.

The tip of the point, around the navigation marker, is armored with riprap, but there are small beaches on both sides. They consist of well-sorted reddish gravel, definitely not like other Puget Sound beaches. Interestingly, the gravel looks remarkably like the gravel used in the upland landscaping and I suspect that at some point in the past folks may have "enhanced" these beaches with this imported material. The beach at Salter's Point in Steilacoom is composed of similar gravel and I wonder if there is a common, somewhat manufactured, thread.

Flooding on the Puyallup earlier in November left an enormous amount of fresh wood washed up on the beaches from here on down into Commencement Bay.