Save Ocean Beach

The natural and physical resources of Ocean beach and its adjacent City Dunedin are under threat and you can help!

A beach ramp St Clair lifesavers say is essential to save lives will be re-opened by late October.
That information came after a passionate public meeting on the issue of the battered seawall last night.
And it is one good result for concerned residents.

Click on the following link to view the news video

Heated debate over sea wall problem | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

A public forum on the battered St Clair sea wall led to some heated debate at the Forbury Park Raceway hall in Dunedin last night.
''This is not a design-by-committee or about beating up the council,'' meeting chairman Cr Andrew Noone said.
''Council is committed to finding a long-term solution but, ultimately, we are going to be relying on the best technical advice.''
City operations manager Tony Avery said it was still not clear what the best solution was.
''We don't actually know what needs to be done. We need to understand why it has failed, the dynamics of the beach and what to do to ensure it stays there for another 50, 60 or 100 years.''
Opus International Consultants, working with the Danish Hydraulic Institute, had been selected from 11 applicants to resolve the problem.
''We have quite a complex engineering problem in front of us,'' Opus senior project manager Steve Rollason said.
''The beach changes all the time.''
Council network maintenance engineer Peter Standring said remedial work had, so far, cost ratepayers $500,000.
''There's a lot to consider and there's too much at risk to do nothing. But, we have to balance that with the safety of the beach, its amenity value and its value to surfers. It has to tick all the boxes.''
However, many at the 200-strong forum expressed frustration at the remedial response to date.
St Clair resident James Dignan said the council had been ''treating the symptom, rather than the problem itself''' and suggested an artificial reef was needed to reduce the effects of wave action.
Dunedin resident Dave Ross said he was ''angry at the ongoing financial cost to ratepayers''.
''What is the guarantee this won't happen again?'' he asked.
Surfers Tony Ryder and Peter Haslemore said the sand erosion had led to the quality of the surf deteriorating in recent years.
''The wave levels haven't changed. The problem is the sand level is so low that the waves are hitting the sea wall for longer,'' Mr Haslemore said.
Graeme Newton, a St Clair Surf Lifesaving Club member for 47 years, said the damage was also endangering lives, as it prevented the club from launching a rescue on the beach.
''If we have a call-out, we can't respond. By the time we get there, someone will drown. It's as simple as that.''
Cr Noone said it was hoped a solution could be found before the surf club season opened at the end of October.
The council has set until the middle of next month for public submissions, with an Opus report due by mid-October.

The public gets the chance to have its say on the future of the St Clair beach and seawall this evening.

Click on the following link to view the news video

Consultation over Esplanade 'possible' | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

A request for public consultation on the future of the Esplanade at St Clair is to be made to the Dunedin City Council, following a public meeting at the St Clair Surf Life Saving Club last night.

Dunedin Mayor Dave Cull recently said a decision on how best to protect St Clair Beach and the sea wall would be based on expert engineering advice, not ''expert public opinion''.
However, there was some hope when council roading network engineer Peter Standring told last night's meeting it was ''possible'' for the DCC to consult people in the community with knowledge of the beach.
More than 60 residents, business owners, surfers and regular beach users attended the meeting called by Dunedin South Labour MP Clare Curran, to discuss the next steps towards fixing the problems at the Esplanade.
Large sinkholes appeared in the paved Esplanade walkway in May during a period of high tides and heavy seas, when fill was sucked out from behind the wall after waves got under the structure.
The numerous problems with the sea wall over the century since it was built have always generated a healthy level of public opinion on how to resolve them.
Last night was no different.
Among the issues brought up at the meeting was a concern there was no safe access to the beach, and many surfers said they were just jumping over barriers to get to the water.
There was also concern the St Clair club's ramp was out of action, meaning there would be long delays in any surf rescue operations in the area.
It appeared there were no councillors at the meeting. However, Mr Standring said the council was looking at the issue as a matter of urgency.
Many at the meeting agreed all the problems at the Esplanade were caused by the reshaping of the ''corner'' by the St Clair Hot Salt Water Pool.
Some who had lived in the area for more than 30 years said they believed it was causing the sea currents to create a ''gouging effect'', which sucked sand away from the beach.
They believed the cheapest and easiest way to fix the problems would be to remove the corner.
The meeting concluded the council should recognise the knowledge of local residents, and they wanted to be consulted by the council before any final decision was made on the future of the Esplanade.
While Mr Standring's belief it could be done brought some hope to the meeting, there was also scepticism. Local resident Vince Ryan said there had been similar community meetings in the past where similar advice had been given but the DCC had not taken it.
Ms Curran said the public knew there was a DCC process in place, but the missing element in the equation was the opinion of the community.
The meeting voted to have Ms Curran approach the DCC and request regular meetings with the community, and to ask if the community could formally consult on any developments.
It was hoped another community meeting could be held, this time with council staff providing information.
A reference group will also be formed to liaise with the council on the issues.

Calls for accountability over failure of sea wall | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

Calls for accountability were met with pleas for a trial before a hanging as Dunedin city councillors considered the failure of the St Clair sea wall yesterday.

The debate came as councillors approved plans to recruit an international consultant to help with sea wall repair plans, following repeated damage culminating in the emergence of sinkholes in May.
The review was expected to cost the council up to $150,000 and take three months, but was endorsed by councillors at yesterday's Dunedin City Council infrastructure services committee meeting.
That followed a report by council transportation operations manager Graeme Hamilton that identified issues to be considered, from the continued structural integrity of the wall to the benefits of an offshore groyne.
However, Cr Lee Vandervis saw red over the failure to mention the need for accountability in the report, and demanded it be a priority of the review.
Warnings at the time the wall's design was ''incompetent'' had been ignored, and the project had ended up costing ratepayers $6 million, Cr Vandervis said.
''Every single aspect of this project has been compromised and we should have had a much harder look at responsibility way before now,'' he said.
Mr Hamilton said accountability could ''certainly'' be considered, but whether the design or those who accepted it were to blame was difficult to say.
That prompted Mayor Dave Cull to urge caution, saying the review needed to establish the facts before blame could be apportioned.
''We should be having a trial before we have a hanging,'' he said.
The sea wall was designed by Duffill Watts and King, which later merged with Commes Consulting in Australia to become CPG, before morphing again to become Spiire late last year.
The council struck a deal with Spiire earlier this year to split the estimated $250,000 repair bill to fix earlier damage to stairs and a ramp.
The council had opted for the deal rather than expensive and risky court action, but neither party had accepted liability for the wall's faults.
Mr Hamilton indicated last month the council could seek further costs from Spiire if the design was found to have contributed to the sinkholes.
Committee chairman Cr Andrew Noone told yesterday's meeting the deal with Spiire related to the failure of the steps and ramp, but the council now had ''a bigger picture of failure'' to consider.
Most councillors yesterday favoured the review, although Cr John Bezett urged his colleagues to ''get on with it''.
He predicted finding a way to retain sand at St Clair Beach - and the cost of doing so - would be the ''nub'' of the issue.
The council needed the facts as quickly as possible, but it would be up to ratepayers to decide if the ''serious'' costs that came with it were acceptable, he said.

Public gets no say over St Clair | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

A decision on how best to protect St Clair beach and the sea wall will be based on expert engineering advice and not ''expert public opinion'', Dunedin Mayor Dave Cull says.

Council staff are expected to decide by the middle of next week which of three short-listed firms the council will hire to provide it with advice on the best engineering solution for the long-term protection of the beach and sea wall.
The danger of fluctuations in sand levels on the beach was highlighted last month when large sinkholes opened up in the Esplanade at St Clair.
The city has, as a result, to date spent $500,000 on stabilising the wall and Esplanade.
It is expected that work should be completed at the end of this week.
The holes appeared in the walkway when the level of the beach became so low during a period of high tides and heavy seas, that the bottom of the sea wall was exposed allowing waves to get underneath and suck out fill from behind it.
The numerous problems with the sea wall over the century since it was built have always generated a healthy level of public opinion on how to resolve them.
They have also resulted in many technical, engineering and scientific reports, studies and assessments of what the issues are with keeping the sea at bay.
Council roading maintenance engineer Peter Standring said all those reports would be provided to the chosen company.
It would assess them, conduct its own assessment, keeping in close contact with council engineering staff, and report back - probably within six weeks.
He expected staff would be in a position to report to the council by September the ''best engineering advice'' it had for a long-term solution.
Mr Cull said councillors would then have to decide what to do based on the expert advice.
There would be no public consultation on that decision, as such, although people would be kept informed of what was happening.
Mr Cull said it would be irresponsible of the council to base a decision like this on public opinion in a situation that required specific technical and engineering expertise.
He was not certain whether the council would be provided options, but expected any advice would be accompanied by expert reasoning.
He would not speculate on what would happen given options that were significantly costly to the ratepayer.
''Clearly, we have to weigh up what value we get from what we are going to spend.''

Sea-wall work almost done | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

Work to secure and stabilise the damaged sections of sea wall and the Esplanade at St Clair should be completed by this weekend.

Since the installation of new sheet-piling at the bottom of the sea wall was completed last week, contractors have been filling gaps behind the wall to protect it from the thumping of waves.
A gap between the sea wall and the original sea wall behind it has been filled with fine gravel, and holes that appeared in the Esplanade have been filled with coarser gravel.
The holes were created when the wall was undermined by high tides and heavy seas that removed more than a metre of sand from the beach at the foot of the wall and created gaps through which fill from behind was sucked out under the wall.
Council roading maintenance engineer Peter Stand-ring said he expected the filling work to be completed by this weekend.
The sheet-piling and fill would protect the wall from further damage, but the area round the St Clair Surf Life Saving Club's ramp would remain closed to the public for a significant amount of time yet.
Contractors would next go over the damaged area looking for any less obvious damage that had not been picked up yet.
The next major stage of work would be looking at addressing the sand retention on the beach in the long term.
Council staff had narrowed down the 11 expressions of interest received from consultants across the country for that work, and were in discussions with three companies.
It was hoped a decision on a consultant would be made by the middle of next week.

Impending high tide concern at St Clair | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

Sinkholes at the Esplanade at St Clair will be filled with gravel as concern builds about high tides expected later this week.
A perigee tide is expected, building up from today, and the king tide is expected on Friday.
The tides are similar to those that three weeks ago stripped St Clair Beach of sand, exposing the sea wall's toe and undermining the Esplanade.
It was ''fair to say'' that because the fill had gone from behind the sea wall, council staff and engineers were ''a bit nervous'' as to how the wall would stand up to the pounding waves the high tide would bring, council roading maintenance engineer Peter Standring said yesterday.
It had been decided to fill the small gap between the sea wall and the old sea wall behind it with a fine pea gravel, and then fill the sinkholes with bigger AP40 gravel, to brace the walls and support the wall's anchors.
The use of gravel meant if there was any need in the future to drill down into the holes, that could still be done.
On the beach, part of the St Clair Surf Life Saving club's beach access ramp was removed at the weekend so contractors could plug the final gap under the wall.
Mr Standring said the ramp was basically dangling in its place and was too dangerous to work under.
The concrete ramp was old and unsafe and it was decided it would be replaced with a new ramp as part of the work on fixing the sea wall, he said.
Contractors who had gone to the southwest end of the beach to move big rocks back on the rock wall there, found the bottom section of a set of stairs had come adrift, and the stairs had been removed.
The steps have been blocked off for safety reasons.
Mr Standring said the future of those steps was already ''under a question mark'' as earlier engineering advice had been they were at risk of ongoing damage from wave action.

Sun, surf and not much sand at all | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

As the cost of plugging the gap under the St Clair sea wall spirals past $300,000, Debbie Porteous' thoughts turn to sand.
When the new sea wall was built in front of the old one at St Clair in 2004, a lot of people said something also had to be built to protect it.
After years of increasing beach scouring, the eventual exposure of its toe and inevitable sink-holes in the footpath above in the late 1990s, there were many warnings from experts.
The warnings were that wave pressure and sand erosion at St Clair Beach needed somehow to be mitigated or the wall, and the beach, would take a beating.
They were accompanied by high level of concern from the community.
Every person agreed that when waves reflected off the wall they scoured the beach.
As the beach became lower the waves could reach the wall more easily, smacking into it harder and scouring more and more sand from its front.
Contractors work on the last section of sheet piling going in in front of the sea wall to stop it being undermined.
Contractors work on the last section of sheet piling going in in front of the sea wall to stop it being undermined.
Sand moved to and fro, but it was clear it was not returning at the rate it was leaving.
Canterbury University engineering dean Prof Alex Sutherland warned that without mitigation, the vertical sea wall would continue to lower the beach level.
The Dunedin City Council's consultant engineers said a breakwater was needed to break waves offshore and create a reservoir of sand at the beach.
A Otago Regional Council hearings panel - despite turning down consent to build a breakwater - suggested the city council investigate options to mitigate waves hitting the wall and beach scouring.
''... and a longer-term management strategy to address these effects as far as is reasonably practicable.''
Members of the public welcomed a new wall, but said it should be only the first step in protecting the area.
It was the appearance of sinkholes in the Esplanade - not unlike those that have appeared there now - and the exposure of the original wall's foundations in the late 1990s that prompted the council to start seeking advice.
Councillors were soon advised the wall was unstable, and could collapse in the next big storm.
A new wall was built in front of it in 2004.
At the time council staff were clear further protection also had to accompany the wall.
They suggested that long-term, the installation of a $2.5 million artificial offshore reef, made of sand-filled sausages, to reduce the power of the waves could solve the sand erosion problems.
But they also said it would be several years before the council would be able to consider such a project.
A great citywide debate about what to do about the wall followed.
Engineer Maurice Davis, then of Duffill Watts and Davis, who prepared the initial beach report for the council, told a public meeting at the time a wall was not ideal at all. But because one had been built there at a time when no-one knew what effect it would have, and houses had long since been built behind it, the city was stuck with it.
A new wall would have to be built in the same place, as close to the old wall as possible.
Its negative effects could be alleviated by encouraging the deposit of sand on the beach and limiting the sand's longshore drift, he said.
As well as the artificial reef idea, people at the meeting also discussed other long-term options, including building a permeable or solid breakwater out from the headland and building sand-trap fences along the beach.
Duffill Watts and Davis eventually recommended the council build a 20m breakwater out from the St Clair salt water pool.
It is understood its plans were reviewed by other experts, who recommended the breakwater extend further than that, but when the council eventually applied for consent to build the sea wall, a 20m breakwater was included.
It was not a popular idea.
There was a strongly negative reaction from surfers, and a regional council panel declined to give resource consent for it based on the health and safety risks it posed to surfers.
The panel was also concerned the breakwater would project into a known channel used by surfers and affect wave breaks and currents in an area that was so important to surfing.
''We consider that the value that a readily accessible good surfing beach offers Dunedin must be preserved. The rock groyne would be inconsistent with the classification of St Clair beach as a coastal recreation area,'' its decision said.
In 2005, a report for council prepared by Duffill Watts and King on damage to a sea ramp on the new wall raised the issue of the breakwater again.
It said the wave conditions of the previous six months and the ''dramatic degrading'' of the beach provided a sound argument for the council to reconsider the project.
The beach profile was ''seriously sucked down'' and there was little sand protecting the base of the wall and ramp, director Barry Chamberlain told councillors.
It was left to staff and a council consultant to consider the groyne suggestion.
It seemed to fizzle out.
In 2007, the council commenced a substantive investigation into stabilising the city's beaches, following storm damage to dunes at Middle Beach.
Submissions reflected concern from the community about the sea wall's effect on erosion at St Clair Beach, and support for an artificial reef to solve the problem again came through strongly.
At some point, the council suggested taking sand from Tomahawk to replenish St Clair and Middle Beaches, a plan abandoned after Tomahawk locals did not take kindly to it.
From the investigations came the long-term Ocean Beach Domain Management Plan.
Adopted last year, it says the area in front of the sea wall is managed by a separate city council process and proposes no action for the area other than maintaining the sea wall.
The nature of that ''separate process'' is unclear, although parks and recreation manager Mick Reece said it was related to the consent, which says the wall shall be maintained in good repair throughout the 35-year term of the consent.
Chairman of the hearings committee Cr Colin Weatherall said St Clair Beach was out of the project's scope.
''It was always going to be the difficult quantum, but we never envisaged what's happened there now.''
Last week, he asked council staff for a report as soon as possible.
If everyone said the sand migration issues needed to be addressed, why has it not been done?It seems the reasons are complex.
The answer would require a close reading of dozens of reports, studies and assessments on the matter done by council staff and experts over the past 15 years.
There have been changes in councils and council staff.
The man responsible for the sea wall now is transportation operations manager Graeme Hamilton, who says he inherited the sea wall from the council's parks and recreation department 18 months ago.
Parks and recreation inherited it from the city architect/city planning department, which dealt with it when the wall was replaced.
Mr Hamilton's focus is on fixing the immediate problem: stopping the Esplanade from slumping any more.
He has not thought too much about sand yet.
''If the wall was built on rock, there wouldn't be an issue with sand.''
The long-term options for sand retention would be determined and reported back to the council for a decision, he said.
At this stage, it seems councillors will not receive that report until September, as it will not be ready for the next committee round in July.
Cr Paul Hudson, who was on the hearings committee which dealt with submissions on the 2008 sand investigations, said the whole area was part of those discussions and councillors were well briefed on issues along the coast, including St Clair, as part of that.
It is not that nothing has happened to try to divert the sea's energy at St Clair; work such as dumping stones at the foot of the wall had taken place from time to time, he said.
It seems likely the council may now have to seriously consider doing something about the sand situation.
And that will come back to money, of course, of which there is not much to splash around.
The 2004 sea wall and Esplanade was originally to cost $3 million and ended up costing about $7 million.
The cost of another major project is unlikely to be something any council, especially one in a tight spot, will welcome.
Any options involving more rocks or structures on the beach or in the water are also unlikely to be popular.
But perhaps people will have to accept it could well be a choice between some effects on the amenity - visual or otherwise - and no beach at all.

St Clair sea wall: Some food for thought | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

Steve Moynihan, of Moynihan Coastal Consulting Ltd, provides some food for thought about the St Clair sea wall.
Quite a lot has been said about the St Clair sea wall.
I have joined the party late, mainly because I have had to carry out some calculations and prepare a drawing.
I am a coastal engineer working from home in Omakau (not because of expected sea-level rise), and I have been involved in new beach design.
Research on many beaches has shown soft (sand/shingle) beaches will adopt an equilibrium shape in plan when adjacent to a headland such as the seawater pool area at St Clair.
Equilibrium is a state where there is no more erosion because the shoreline is everywhere in line with the incoming waves. A beach that has not reached an equilibrium shape will continue to erode until it does so. This is the case at the St Clair corner, which explains why there have been problems there since first occupation in the late 1800s.
The picture published here titled ''Erosion'' has a red line showing where the back of the beach wants to be. In trying to reach this line, the beach may encounter hard rock or a seawall which constrains the back of the beach to the line of the wall.
However, a sea wall does not stop erosion and the seabed in front of the wall will have been continuing to lower until it reaches a depth at the location of the wall, as if the back of the beach did in fact lie along the red line.
The wall would have no problems if it had a strong base that went below the eroded depth, but this would not leave much of a beach in front. Of course the whole situation is very dynamic and sand will come and go, but the overall effect would be that of a poor beach.
A change could be made by pushing out the headland into the sea by way of a breakwater.
The picture labelled ''Beach'' has a yellow line showing where the edge of the beach would lie with a 150m breakwater in place. The result would be a beach of up to 50m width, with the sea wall sheltered by permanent sand.
My inexpert drawing ''Breakwater-Beach'' shows what this would look like. There would be room for activity like beach volleyball. Studies would be required to show no harm to the surf break. More beach could be obtained with a longer breakwater.
The downside is cost. A strong breakwater would be required - costing $8 million to $10 million, depending on whether sand would have to be imported, on final design, studies, and consent costs.
Food for thought anyway.

Esplanade sinkholes may get bigger: DCC | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

Sinkholes in the Esplanade at St Clair could get bigger over the next week, but the Dunedin City Council is happy the damage is contained to that immediate area.
It says preliminary tests indicate there is no immediate concern about the safety of the rest of the sea wall.
At least one business owner in the area yesterday expressed concern about a lack of information being provided by the council on the status of the wall.
Starfish Cafe co-owner Cushla Dodds said because the holes appeared to be growing and the council had told her nothing, she had checked her insurance policy, just in case. She said she knew other businesses had too.
Business was being affected because people thought they could no longer walk around the Esplanade or bring their dogs there, she said.
People also wanted to know the long-term plans for the seafront. She had not contacted the council, but felt she should not have to.
Next door, florist Carley Jones told Radio New Zealand that each day the drama went on, the more scary it became.
Council roading network engineer Peter Standring said the situation yesterday was that the council expected sinkholes in front of the South Coast Board Riders' Association at the north end of the sea wall would continue to grow in a northerly direction over the next week, as contractors worked in two-hour bursts around tides, to plug gaps underneath the sea wall at that end.
The amount of walkway fill being sucked out through those gaps had already been reduced by remedial action taken since the first hole appeared on Sunday, but material could still disappear until sheet piling along the base of the northern end of the wall was completed, he said.
The sheet piles were being sunk 3m deeper than the foot of the sea wall along the 50m section of wall.
The work was being done in sections and had started around the St Clair Surf Life Saving Club's ramp, where the biggest gaps were. It was expected to take at least another week, because access was limited by the tides.
He said it was anticipated the pits in the walkway would eventually extend along more or less that whole section of the walkway, to the northern end.
However, engineers had indicated the damage would be contained to that area.
A preliminary check by engineers and a ground-penetrating radar had not revealed any voids under the remainder of the wall or walkway along to the salt water pool.
Mr Standring said the priority was to plug the gaps where the beach level had gone below the bottom of the wall.
A more extensive assessment of the rest of the wall would then be made and a long-term response considered once that work was completed.
A portion of the Esplanade walkway along its length and about 3m back from the wall would remain cordoned off until at least then. The cordon still allowed room for foot traffic.
Council operations manager Tony Avery said the council had not approached businesses or residents in the area because there was no concern about the remainder of the wall, although it certainly would if there were any concerns.
He said anyone wanting information could contact the council on 477-4000.

Assessments for seawall | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

A full assessment of the St Clair seawall is expected to start next week.
Advice will also be taken on providing a long-term solution to problems such as the one which caused a section of the Esplanade to be undermined.
While the integrity of the wall was believed to be still intact, the Dunedin City Council would have the entire seawall assessed as a precautionary measure, council roading maintenance engineer Peter Standring said yesterday.
The assessment would be carried out by contract engineers.
The first of several large holes appeared on Sunday behind the seawall in front of the St Clair Surf Life Saving Club and the South Coast Boardriders' Association, after heavy seas and high tides depleted the beach of sand, exposing the toe of the wall.
That allowed waves to flush behind the wall, washing out the backfill, causing the paving above to collapse.
The area from Forbury Rd to the north end of the wall is cordoned off and most access from the Esplanade to St Clair Beach is closed until further notice.
Tracked excavators have been on site since Monday, shifting rocks to protect the bottom of the seawall.
Vertical sheet steel piling is being installed in front of the seawall, on either side of the lifesaving club's ramp, along with cross-bracing under the ramp itself.
Mr Standring said contractors would backfill the area between the seawall piles and the sheet piles with concrete today and tomorrow.
He said much of the beach was at the lowest level staff had seen.
Because tides were so high, the waves had been hitting the sea wall without breaking, putting significant pressure on it. The situation was expected to improve after Tuesday's king tide.
However, it had highlighted the need for a long-term solution which worked with the natural environment, he said.
''This is a natural occurrence and we will be getting expert advice on how to best deal with these challenges in the future.''
He said some St Clair businesses and residents had reported heightened building vibrations this week.
That was ''more than likely'' happening because of the lack of backfill behind the wall at the northern end, which would normally dampen pounding waves.
He emphasised it was important for people to avoid the cordoned-off area while work continued.
There was public access to St Clair Beach via Middle Beach.
Updates on the project are available on the council's website.

Fresh holes appear in Esplanade | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

Contractors continue to battle sea, sand and snow to shore up a gap under Dunedin's St Clair sea wall.
A relentless sea continued to suck out fill from under the Esplanade yesterday, creating new holes in the pavement and expanding cavities that appeared on Sunday.
A mound of large stones was placed in front of the bottom of the wall in the affected area late on Monday and early yesterday to try to prevent more fill being sucked out under the sea wall by continuing spring tides.
Sheet piling is also being installed to support and protect the wall and infill concrete to further plug the gap is to be poured today.
Dunedin Mayor Dave Cull says the unexpected cost of the work will not affect residents' rates next year, but could in 2014-15.
The Dunedin City Council's roading network manager Peter Standring said the height of the tides was preventing crews accessing the foot of the wall for more than a few hours at a time.
The rock piles had managed to stop much of the problem, but some fill was still being sucked out. It was hoped pouring concrete behind the rocks would stop that.
Crews continued to work on the problem at low tide, about 11pm last night, and would be back again at low tide this morning.
Mr Cull yesterday responded to criticism over the functionality of the sea wall, which was installed by the council in 2004.
People seemed to have forgotten there were many and similar problems with previous sea walls at St Clair, he said.
The first two sea walls, built in the 1880s, lasted only a few years.
A sea wall officially opened in 1913 was covered in by the existing sea wall in 2004 after concerns its base was "kicking out" and after the dumping of massive boulders in front of the wall base following scouring of sand by large swells.
Sinkholes also opened up the Esplanade before the present sea wall was erected.
Mr Cull said the council's focus was to ensure the structure was as strong and protected as it could be for as long as possible.
There was no question of a wall not being at St Clair, so the council had to manage the situation as best it could.
As with any manmade hard surface put in to hold the sea back, issues would be ongoing.
The council would not just rush in and try to "fix" the wall, until the full extent of the problem was known.
He said the cost of fixing the sinkholes would not affect next year's rates because the 2013-14 budget was already set.
Once the Esplanade costs were clear, they could be covered by any surplus at the end of 2012-13, or an overspend could be covered by finding savings or reprioritising projects in next year's roading and maintenance schedule, or rates could be affected in 2014-15.
Council parks manager Lisa Wheeler said there would have to be discussions about how to prevent further erosion.
The council's management plan for the Ocean Beach reserve was focused on protecting the dunes to the north of the sea wall, not the sand in front of it.
The sand at St Clair left and returned almost constantly and the indications were that keeping consistent levels in place would be "far too expensive", she said.

St Clair Esplanade opens up | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

A further hole has opened up in the Esplanade at St Clair and two holes which appeared yesterday have merged into one larger opening.
The holes in the paved area in front of St Clair Lifesaving Club first appeared yesterday as big swells pounded the coast.
The new hole is on the Lawyers Head side of the surf-lifesaving ramp.
Dunedin city council staff are assessing the situation amid a steady stream of onlookers. 
About 2.30pm yesterday, police and contractors began to cordon off the seaward side of the Esplanade, from the St Clair Lifesaving Club to the car park, as a precaution.
The Esplanade was full of people watching the waves crashing against the sea wall.
One of the holes in the paved area in front of the life-saving club grew from about 1m long to about 4m long and others had also grown in size after the high tide at 4.30pm.
Swells of 2.3m are predicted and tides of similar heights are forecast for next few days.
Life-saving club president Antony Mason said he called the Dunedin City Council and Fire Service after finding the tiled area to be a ''bit spongy underfoot''.
''It got bad real quick. Within an hour there were two holes.''
The news grew worse when he realised the club's ramp to the beach had moved about 20mm and water was going under the ramp's tunnel, he said.
''We've got no access to the beach and the polar plunge is in three weeks.''
He had seen bigger seas and the beach in worse conditions than yesterday.
Dunedin City Council roading engineer Peter Standring inspected the site yesterday afternoon and found a significant ''drop out'' below the tiles.
''If you looked back underneath, the tiles were suspended.''
It was for that reason the Esplanade was cordoned off, he said. While the tiles looked fine on the surface along the rest of the Esplanade, there could be a void opening up underneath.
He believed yesterday's high tides and swells shook the tiles loose but the undermining of the ground had probably occurred over time, as the sea sucked material out from behind the sea wall.
''It's been an ongoing process. It highlights the need to look at everything.''
From his assessment of the site, he did not believe the integrity of the sea wall had been compromised.
Engineers would visit the site today to get a better idea of what was happening, he said.
The holes are the latest problem to beset the Esplanade.
The stairs and ramps to the beach have failed several times, due to what the council believed was a combination of construction and design faults. The high tides also brought surface flooding to Portobello Rd and the streets off Portsmouth Dr late yesterday afternoon.

Video: Huge waves pound seawall | Otago Daily Times Online News : Otago, South Island, New Zealand & International News

St Clair Beach was bombarded by monsters from the deep yesterday evening. The seawall at the Esplanade shook from the impact of 2m waves, which were breaking 50m offshore and sending spray 20m into the air. 
Seawater covered the 6m-wide walkway and nearly reached the road. 
Dozens of people visited the Esplanade to see the big wave action, take photographs and play in the spray.
''I could see the spray from Andersons Bay. At first, I thought it was sea mist,'' St Kilda Surf Life Saving Club member Steve Wilson said.
However, the waves were even bigger on Saturday night, he said.
''I've never seen a tide like that. It was the biggest I've ever seen around the Dunedin coast.
''It was coming up the drains in Portsmouth Dr and either side of the Edgar Centre was under a foot (30cm) of water.''
A clutch of intrepid surfers braved the waves yesterday, but took care to keep close to the St Clair Salt Water Pool.
The Surf Forecast website recorded the swell at 2.11m at 6pm yesterday. A 1.7m high tide is expected at 6.30am today and a 2.8m high tide at 7pm.
Dunedin City Council parks and reserves manager Lisa Wheeler said staff would be checking the dunes for erosion caused by the high seas today as soon as the tides allowed.
A MetService severe weather watch for high winds in Otago was dropped last night. North Otago bore the brunt of high winds yesterday with gale force gusts of 46kmh to 64kmh experienced at Oamaru and Moeraki in the afternoon.