PROPOSED DRAINAGE SCHEME AND HARBOUR ENGINEERING

1 PROPOSED DRAINAGE SCHEME AND HARBOUR ENGINEERING

The Department of the Marine in their submission to An Bord Pleanala dated 16th March 2006 raised very serious concerns as to the suitability of the design of the proposed harbour breakwaters which they felt were too low to prevent severe wave overtopping.

Based on the additional information provided to An Bord Pleanala it appears that Wicklow County Council/Sispar have made no modifications to the engineering design of the proposed harbour breakwaters.

At the oral hearing in March 2006 it was advised by Wicklow County Council/Sispar that “physical wave model tests had been commissioned and would be complete within a three month period”[1]. These physical model tests were commissioned to determine whether/which modifications of the breakwater design were needed. A commitment was given to the Inspector by Wicklow County Council/Sispar that the eventual report would be made available for public inspection.

Wicklow County Council/Sispar have failed to comply with a specific commitment they gave to the Inspector at the Oral Hearing regarding physical wave modelling tests.

The EIA should consider carefully the impact of the proposed coastal works on areas removed from the development. In a case such as this, wave modelling would be a desirable component of the EIA to assess the effect of the coastal transformation on the wave climate in the vicinity of the development.

It is totally unacceptable that the results of the physical modelling tests carried out since the oral hearing have not yet been made available for public inspection by Wicklow County Council/Sispar.The results of these tests are critical in the context of the coastal setting of the proposed development for Greystones for the following reasons:

1.1 Department of Communications, Marine and Natural Resources submission

The Department of Communications, Marine and Natural Resources in their detailed submission dated 16 March 2006 to An Bord Pleanala stated;

· In section 11 “Wave Disturbance Modelling” that “the department would suggest that the project be redesigned to ensure that only acceptable wave heights are achieved in the marina”and that “overtopping should be discussed and analysed in the EIS and an opportunity given for public comment.”

· In section 13 “numerical Models” that use of numerical models such as LITDRIFT and LITLINE” as the sole design tool as has been done in this case needs to be viewed with a very high level of caution”.

· In section 14 “Wave Sheltering” that “details of the wave sheltering assumed in the modelling of the new development are not made available in the EIS” and that “these assumptions are central to understanding the simulations carried out with the new development in place”.

· In section 14 the Department strongly concludes that “if modelling is incorrect, as it appears to be, project design following from such modelling would appear to be highly questionable”.

1.2 Brief of evidence of Clon Ulrick BSc(Eng) at the Oral Hearing

The brief of evidence of Clon Ulrick BSc(Eng) at the Oral Hearing dealing with coastal defences and marine works stated;

· in section 6.2.3 that “the north breakwater, which has a crest height of +6.5 mOD, will be prone to severe wave overtopping during extreme storms” and that it is proposed that the effects of wave overtopping will be investigated by physical modelling”.

· in section 6.2.4 that “the south breakwater, which has a crest height of +6.5 mOD increasing to +8mOD near Cliff Road, will nevertheless be prone to severe wave overtopping during extreme storms” and that “the effects of wave overtopping are being investigated further by physical modelling”.

· in Section 8.2.6 that “physical model tests that are commissioned and will be completed within three months will be required for final assessment of the overtopping and determine whether/which modifications of the breakwater design are needed.”

· in Section 8.7.2 that “the reclamination levels for the residential and commercial developments have been selected to allow for global warming and sea level rise, using conservative (safe) estimates of future sea level rise based on current best practice guidance.” I question how this assertion can be made when the developer does not even have any local tidal data? He also stated that “the area on the south side of the harbour for the car parks and boat storage is a little lower and will be subject to some wave run up in extreme weather events.”
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1.3 Height of the breakwaters dictated by politicians

It appears that the engineering of the harbour breakwaters has been dictated to by local politicians rather than by sound breakwater engineering advice.

The engineering design of the crest height of the breakwater has been constrained by “the Variation to the County Development Plan to +6.5mOD”.

With the help of the Dun Laoghaire harbour master I checked the heights of the east pier of Dun Laoghaire harbour and found them to be significantly higher than the proposed breakwaters for Greystones Harbour. It should be noted that the east pier of Dun Laoghaire harbour is subject to wave overtopping.

It is unacceptable that fundamental engineering design issues appear to have been made for political reasons rather than from sound marine engineering advice.

1.4 Redesign of the proposed development

The relocation of club buildings further east to positions on or near the south breakwater which are “the most exposed position within the masterplan” place those structures at risk of flooding. It is unacceptable that the results of the physical wave modelling test which would show the extent of the predicted wave overtopping has not been published.

· Breakwater performance, in particular armour stability, maximum runup, wave reflection and wave transmission, is normally checked with a physical model in a wave flume.

· The proposed residential and commercial structures will be totally dependant upon the protection of the harbour breakwaters against the wave energy from the sea.

1.5 History of coastal flooding at Greystones North Beach

The developers admitted at the oral hearing that the destruction of dwellings on the North Beach in the 1930s was not considered by the developers.

· There is a risk to any structures on the seafront especially considering the maritime history of the Greystones North Beach area.

· The OPW website http://www.floodmaps.ie/ details contemporaneous newspaper articles describing a tidal wave which destroyed a number of cottages along this same stretch of coast in the 1930’s. The planned new structures are proposed to be located, not on a flood-plain, but on the sea bed in front of the site where these cottages were destroyed by the sea.

· From an equity perspective it is important that any new structures constructed at Greystones Harbour and North Beach will be fully protected from the risk of inundation from the sea. It would be grossly unfair should individuals who have invested substantial sums of money in these coastal structures suffer substantial flood losses with consequent risk of negative equity as a result of inadequate protective breakwaters.

1.6 Correspondence with Wicklow County Council

On 3rd October 2006 in an email from the Director of Services for Wicklow County Council, Sean Quirke, he stated to me that;

· “Physical modelling was carried out in the Danish Hydraulic Institute. However I have not received the final report to date.”

Following a number of follow up requests to Mr Quirke by me for sight of the physical wave modelling report he advised on 7th December in a further email that;

· “This report is being prepared for the construction phase of the project and is not required for planning purposes. I have spoken to the consultants and they have confirmed that the report will not be finalised until a planning decision has issued in order to take account of any conditions or changes included in the decision.”

In December 2006 both Councillor Deirdre De Burca and Deputy Liz McManus TD requested a copy of the report. These requests were also refused.

While the report was not specifically requested by the Board, it seems unusual the developers would refuse to make it available to a public representative. Indeed if the report did, as claimed in the attached letter confirm that “the fundamental design of the harbour breakwaters… are robust” it might be expected that the developers would be anxious to make the report available to the Board and to the public to alleviate any concerns about the adequacy of the structures.

I therefore respectfully request that Wicklow County Council/Sispar be instructed by An Bord Pleanala to publish the results of the physical wave modelling tests as committed to by them during the oral hearing.

1.7 Drainage scheme for the proposed development

Drainage and watermain drawings were included in the additional information (C001, C002 and C003) however:

· There is no narrative included in the additional to explain the proposed drainage system in the development.

· The drawings on the drainage scheme refer to a number of storm attenuation tanks intended to store a 1 in 50 year storm event of a 4 hour duration. This development will be under an ongoing threat of wave overtopping. This treat will increase over time as the predicted impacts of climate change occur. I believe that the standard set of a 1 in 50 year storm event is insufficient for a flood prone development under the precautionary principle and that these proposed tanks are of insufficient size. I believe that the 1 in 50 year storm event standard is inadequate.

· This is particularly so given the stated policy of Wicklow County Council FR05 on minimum flood design standards as stated in the Local Area Plan for Greystones / Delgany.

1.8 Greystones area Local Tidal Data

In correspondence with Wick County Council it was confirmed that there is no historical record of local tide levels for the Greystones coastal area.

The EIS uses Dublin Port tidal gauge data.

It is unacceptable for a scheme such as this on the Greystones foreshore to proceed without any accurate local historical tidal data.

1.9 Health & safety risk

· The safeguarding of the health and safety of any potential residents in the proposed new residential structures of this development should be of paramount importance.

· The consequences of incorrectly calculating flood levels are not just a risk to parked cars (particularly in the underground car parks) and properties but also to the lives of those who occupy the apartments. A potential health and safety risk therefore arises in the proposed new development at Greystones Harbour and North Bach arising from possibility of flooding of the commercial and residential units and their underground car-parks.

· At the oral hearing Wicklow County Council admitted that the tidal destruction of dwellings on the Greystones North beach in 1929 was not considered in the EIS;

· The existing harbour is subject to wave overtopping. The EIS fails to disclose the height above OD Malin of the existing harbour for comparison purposes;

1.10 Local Area Plan – minimum flood design standards

Wicklow County Council state in the draft LAP for Greystones Delgany in Policy FR05; that all new development must be designed and constructed to meet the following minimum flood design standards;

· For development in general - the 100 year flood
· Along the Coast - the 200-year tide level

However it has been confirmed to me by Wicklow County Council that they have no idea as to what this policy equates to in terms of height above OD Malin.

1.11 Under building car parks

I believe that under the Precautionary Principle that the under building car parking proposed for the development will be at serious risk of inundation from the sea. In particular I draw your attention to the following:

· I note that the under building car parking in Blocks “J”, “I”, “H”, “G”, “F” will have a ground level of 2.2m OD as per Site Section 8-8 DWG No. pSc_08_a

· I note that the under building car parking in Block “G” appears to have a car park gate with ground level of 2.2m OD as per Site Section 9-9 DWG No. pSc_09_a

· I note that Block “D” under building car parking will have a ground level of 1.5m OD as per DWG No. pD1_01_b

· I note that Block “J” under building car parking will have a ground level of 2.2m OD as per DWG No. pJ1_01_a

These levels are below the 3.0 Metres OD referred to in the Wicklow Development Plan 2004-2010 and below the 4.0 Metres OD recommended by John Sweeney who stated that:

“For the east coast of Ireland, we are suggesting that basements of buildings along the quays and the coast shouldn’t be any less than about 4 metres above present sea level,” “It’s important that a certain element of precaution should be taken in terms of anticipating the future storms surges and high water events.”

The clear implication is that these underground car parks will be subject to flooding.

Clon Ulrick in Section 8.7.2 in his brief of evidence stated that “The area on the south side of the harbour for the car parks and boat storage is a little lower and will be subject to some wave run up in extreme weather events.”

It is unacceptable from an economic and safety perspective that the basements of the proposed structures are accepted by the developer as being prone to flooding as the design appears to ignore the reality of rising sea levels.

1.12 Proposed structures adjacent to breakwaters

In extreme weather conditions there will be severe wave overtopping of both the north and south breakwaters. I content that those structures located too close to these breakwaters will be at high risk of flooding and inundation from the sea. Because of the residential nature of this development I believe that this risk raises important health and safety issues. In particular I believe that the following structures will be at high risk of flooding;

· North Breakwater; Blocks “K”, “J”, “I” and H” could be at risk of inundation from the sea in the event of extreme north easterly weather conditions;

· South Breakwater; Block “M” and Block “O” Club Buildings could be at risk of inundation from the sea in the event of extreme east/south east weather conditions.

I request that a safe buffer zone be made in regard to the distances of the proposed residential structures from the harbour breakwaters. I therefore request the Board to instruct the developer that Block K, Block J, Block I, Block H, Block O and Block M be omitted from the proposed development.

1.13 The Greater Dublin Strategic Drainage Study (2005)

· The Greater Dublin Strategic Drainage Study (2005) recommendation regarding criteria for flooding related to sea level rise is to use a 200 year criterion on the basis that flooding from the sea tends to be catastrophic.

· It is proposed by the Greater Dublin Strategic Drainage Study (2005) that most new buildings should have a ground level of +4.0 m OD (Malin Head) in order to ensure that they are protected from the threat of flooding arising from rising sea levels and increased rainfall intensities due to global warming.

· A minimum ground floor threshold of +4.0 OD will be encouraged for all development to satisfy insurance requirements and potential for rising flood levels as a result of future changes in the global climate

1.14 OPW Planning Guidelines for Public Authorities

I believe that the proposed development at Greystones Harbour is at variance to the OPW Planning Guidelines for Public Authorities.

Development that is sensitive to the effects of flooding will generally not be permitted in flood prone or marginal areas (OPW Planning Guidelines for Public Authorities). Preventing such development, where flooding would result in significant hardship, financial losses or costs, will avoid increasing the existing level of risk and will protect the proposed new development from the human (stress and ill-health, for example) and financial costs of flood events. It will also eliminate or reduce expenditure on flood protection measures and compensation.)

The developer acknowledges in Section 3.2 (page 40) of Hydraulic Studies and Coastal Morphology in Appendix VI of the EIS states that:

“..global sea level rise will give rise to further coastal erosion. The sea level rise will allow waves to reach further inshore and will over time cause erosion corresponding to the new equilibrium state.”

1.15 Implications of Climate Change for Northern Ireland: Informing Strategy Development

I draw the Boards attention to important developments regarding flood risk insurance and positional risk which is most relevant in the context of the proposed development. The insurance industry is now using GPS software to identify which properties are vulnerable to flooding. This software is helping insurers make decisions on whether to insure and the premiums involved.

The Scotland and Northern Ireland Forum for Environmental Research (SNIFFER) have released a report titled “Implications of Climate Change for Northern Ireland: Informing Strategy Development”. This report is particularly relevant in the context of the proposed Greystones Harbour development. This policy document states that:

“The accelerated incursion of new building for domestic, tourist and leisure purposes into the NI coastal zone is a major problem for the future. There appears to be a lack of understanding in the private sector, of the risks inherent in building close to the inter-tidal zone, particularly given that planning control cannot be used as a limiting procedure for future external safety purposes. The lack of a NI coastal zone strategy means that there is no effective planning control as a function of coastal proximity. This absence of policy allows the construction of property into what can be both hazardous positions per se and hazardous for surrounding habitats, within the life span of the property. To some extent the issue of positional risk to flooding/erosion has traditionally been seen as best controlled through private insurance. Both primary and secondary insurance companies are actively constructing (taking advantage of recent GIS and remote sensing methodologies) geo-referenced location, risk and knowledge databases about known flood areas. This means that future premiums could be differentially loaded to the point that owners of coastal property deemed to be at risk, may have to live without insurance cover, or be forced to sell below the comparable market value of such a property elsewhere. It is disconcerting that insurance may be the first de facto non-governmental instrument of control, on coastal living (Clarke, 1998). Insurance companies heightened awareness of climate change means that this instrument is already being conditioned for the effects of future climate change. There is the likelihood of a yawning gap between the public and insurer’s view of desirable coastal accommodation in future decades and issues of negative equity becoming common in the coastal zone. The issue of coastal setback controls on construction with/without short-term life spans or depreciation to zero value in the short-term have still not been discussed within the planning-finance-construction sectors. A sign of awareness maturity for NI will be when these concepts are openly discussed.”
I therefore request that the Bord give this report material consideration in the making of its planning decision on the proposed Greystones Harbour development.