Wednesday, January 19, 2011

Council on alert as tides rise

Bill Hoffman

From: Sunshine Coast Daily

MACHINERY and men are on standby as Sunshine Coast beaches face a pounding from some of the highest tides of the year over the next five days.

Maroochydore Beach is under threat from the highest tides of the year over the next five days. (Nicholas Falconer)

MACHINERY and men are on standby as Sunshine Coast beaches face a pounding from some of the highest tides of the year over the next five days.

The year's highest astronomical tide of 2.09 metres will occur on Friday morning, boosted a further 0.4 metres by a sea level rise caused by the La Nina pressure system.

NASA modelling shows the La Nina impact on sea level heights is at its greatest off the South-East Queensland coastline.

Beach accesses Maroochy M75A, M79A, M86B and M90D have been closed and are likely to remain so through the weekend.

The breakthrough area on Bribie Island, Golden Beach, the Alexandra Headland to Maroochydore strip and Dog Beach at Noosa Woods are all under threat.

Sunshine Coast council coastal zone manager Denis Shaw said close attention would also be shown to the restored beach at Mooloolaba.

While it had held up well in recent heavy seas, the area in front of Mooloolaba Surf Life Saving Club had taken a pounding.

Mr Shaw said the question that remained unanswered was whether sand pumped on to the beach in recent months would shift north to fill in the eroded area or go back out along the Mooloolah River training wall.

He said all hot spot areas would be carefully monitored, including Noosa Main Beach which had performed well after being topped up earlier in the year with pumped sand from the Noosa River.

Mr Shaw said plant hire operators had been put on standby so that any badly affected areas could be quickly protected.

Meanwhile, Jim Cash, a former Maroochy Shire councillor, marine biologist and teacher of marine studies including beach processes, has urged council to show caution before committing to a rock wall from Alexandra Headland to Maroochydore.

Mr Cash is fearful the proposal will do more harm than good.

He wants full consideration given to the Gold Coast model where rock walls buried in the sand well out of the wave zone have seen beaches stabilise in front of them.

He believes erosion problems along that stretch of beach may have started with the rock walling of the area in front of the Alexandra Headland Surf Life Saving Club and adjacent skate park.

“People are rightly concerned about the loss of sandy beach and potential loss of infrastructure,'' Mr Cash said.

“However, it is vital that the issue be fully investigated to ensure that any intervention maintains both the beach and the infrastructure behind it and does not make it worse.''

He said there was a strong possibility that a rock wall in the active wave zone would work against maintaining a sandy beach and could adversely affect Maroochydore Beach.

This was because rock walls built in the wave zone increased the reflective energy of waves.

The stronger backwash drags deposited sand out with it at a greater rate than a natural beach.

“Forever and a day you are left with the coffee rock exposed,'' Mr Cash said.

“This could also result in a stronger inshore current which could have negative erosive effects on Maroochydore Beach to the north.

“Research shows this to be true in other parts of the world.”

Monday, January 17, 2011

Share your king tide photos with state agency

From: The News Tribune

Get out your cameras and head to South Sound shorelines in two weeks to chronicle the highest tides of the year.

That’s what the state Department of Ecology is asking the public to do, for a couple of reasons.

First, Ecology officials would like to have visual images from the Washington coast and Puget Sound at extreme high tides to help them better understand specific areas in shoreline communities where home, commercial buildings, roads, utilities and other pieces of the built environment are most vulnerable to sea-level rise.

Second, they want to get people down to the waterfront to see for themselves what could be in store for their communities in the decades ahead.

“We’re hoping to get hundreds of photographs,” Ecology spokesman Curt Hart said. “If we got thousands, that would be fabulous.”

“We just don’t want photos of people posing,” Hart added. “And we don’t want people putting themselves in harm’s way during high tides.”

Ecology is calling this unusual public participation project the Washington King Tide Photo Initiative. Ecology will post the photos online at Flickr for everyone to see.

The so-called king tides, which occur just a few times each year, are windows into the future, identifying coastal areas that could be inundated with water as the sea continues to rise from global warming.

A 2008 report by the University of Washington Climate Impacts Group and Ecology estimated that sea-level rise associated with climate change could be anywhere from 3 inches to 22 inches by 2050.

Olympia, which sits at the southernmost point of Puget Sound, has the highest high tides and lowest low tides of any community in the Puget Sound area. For instance, the 17-foot high tide predicted in Olympia on the morning of Jan. 24 is more than 4 feet higher than the corresponding high tide in Seattle and more than 3 feet higher than the projected high tide in Tacoma that morning.

Combine that with a slowly subsiding land mass in South Sound and you can see why Olympia was the first city – 20 years ago – to take sea-level rise seriously in the Puget Sound regions.

Ecology officials hope their king tide initiative helps persuade other coastal communities to start planning for sea-level rise too.

To participate, follow these steps:

• Join Ecology’s Flickr group at www.flickr.com/groups/1611274@N22.

• Review the high-tide predictions for your area, including times and dates, at www.ecy.wa.gov/climate change/ipa_hightide.htm. Another series of king tides appear the mornings of Feb. 21-22.

• Take photos during a high-tide event in your area and post them on Ecology’s Flickr group.

Read more: http://www.thenewstribune.com/2011/01/09/1495151/share-your-king-tide-photos-with.html#ixzz1BFNUYfhA