Westshore Beach E R O S I O N. Sandy Beach at Westshore Discussion Notes. November Prepared by: L.W.Dallimore

Transcription

1 Westshore Beach E R O S I O N Sandy Beach at Westshore 1972 Discussion Notes November 2009 Prepared by: L.W.Dallimore 1

2 CONTENTS INTRODUCTION (a) Background... 1 (b) Consultants Reports... 2 (c) Design Presentation... 2 (d) Commencement of Erosion... 3 (e) NCC Engineers Position... 4 (f) Comments on the Komar Report... 4 (g) Comments on the Beca Report... 5 CAUSE OF WESTSHORE EROSION (a) Effects of Severe Storms... 6 (b) Breakwaters and Extensions... 8 (c) Shipping Channel (d) East Pier Mole (e) Starvation of Coastal Sediment CURRENT WESTSHORE EROSION (a) Seabed Gradients (b) Erosion at Boiler (c) Gradient at Boiler (d) Loss of Beach Sand (e) Erosion at Kiwi Beach (f) Erosion at South End (g) Rocks Removed by Public (h) Erosion at Beachhead (i) Condition of Beach PROPOSED BREAKWATER (a) Design Option H Shape (b) Recommended Design (c) Purpose of Breakwater (d) Damage Caused by Seawall (e) Breakwater Construction (f) Formation of Sandy Beach BEACH NOURISHMENT (a) Material from Estuary (b) Material from Marine Parade (c) Material from Inner Harbour (d) Nourishment Programme CONCLUSIONS (a) Responsibility for Damage (b) Alternative to Nourishment (c) Current Westshore Situation (d) Long Term Solution.. 27

3 INTRODUCTION 1 (a) Background We are Charles Street residents who take a caring interest in Westshore Beach. Because of our special interest in matters relating to erosion, we attended the presentation by Paul Komar at the Westshore Hotel and the meeting at the Westshore School. At this meeting, I was referred to the Council Engineer and the NCC website for answers to my questions. The construction of a breakwater was announced at the public meeting held at the School Hall in May 2009 and at a special meeting held for residents of Whakarire Avenue West. Currently, a Resource Management Consent (RMC) is being obtained for the construction of a breakwater, strengthening the old seawall, and forming a new sandy beach (see fig 38). We recognise the need for urgent work in this area and providing a new breakwater will fix the problem, we fully support the Council efforts. Over many years, we have seen the beach deteriorate and more recently, we have been witness to the severe damage caused to the southern end by the 1994 seawall. After discussion with the Engineers at the Napier City Council (NCC) and the Hawkes Bay Regional Council (HBRC), and reference to the numerous reports prepared by the Consultants, we found a variance of opinion on what was happening at Westshore Beach. The NCC has adopted the findings and recommendations in the Consultants reports and will not acknowledge severe erosion. Also, the NCC has adopted continuance of beach nourishment as the option to control erosion. Our opinions on current erosion issues were discredited by the engineers and that reaction limited our options to proceed further because all authority beyond this point will tend to revert back to the advice of the engineers. The purpose and aim of these discussion notes are to present our differing opinion in a summarised format in the hope that someone in authority will consider and debate the subject of erosion at Westshore. The media or an elected Councillor with an interest in Westshore could be an option but memories of the battles faced by a past Councillor on erosion issues offers little faith. If we are unable to get reasonable support for our opinion, we will accept the status quo and wait for the we told you so event. These notes may become a poignant reminder of a 2009 decision made by current City leaders. The real purpose of the proposed breakwater is to control the damage caused by a seawall built in This breakwater should permit the removal of 15 properties from the Coastal Erosion Zone as revised by Tonkin & Taylor in 2008 (see appendix I). The land value of these properties could be restored to the values that existed prior to the CEZ (see supplementary notes). An additional benefit will be the close proximity to a sandy beach and direct access to the NCC Shoreline Pathway. Obviously, we want this breakwater to go ahead but we are aware of a bigger problem and prefer to see attention and funds directed to a solution that is long term and benefits all of Westshore Beach.

4 (b) Consultants Reports 2 The NCC has commissioned several marine engineers and an international consultant to remedy the erosion problem. Reports containing comprehensive data and technical analysis have been prepared by Opus Consultants, ASR Marine Consultants, Met Ocean Solutions, EAM Consultants, Dr Jeremy Gibb, Beca Carter Hollings & Ferner, Paul Komar Oceanographer and Beca Infrastructure Ltd and others. The most recent reports on erosion at Westshore total 894 pages without including the summary by Paul Komar. We confined our reference to the most relevant report by Paul Komar Westshore Erosion Summary and Becas - Whakarire Avenue Breakwater report. These reports make up less than 9% of the information made available by NCC. The reports are comprehensive compilations of technical analysis with many references to conclusions of other experts. Controlling the sea is not an exact science because of the huge variables associated with sediments, accretion, erosion, swell exposure, drifts, wave energy, pre-existing structures, etc. The current practice for Govt and Council engineers is to involve as many marine engineering experts as possible. This tends to spread the risk and dilutes blame amongst the experts involved, in the event of a failure. The NCC has adopted the construction of a breakwater and the continuance of the nourishment programme in accordance with the recommendations of their consultants. Our meeting with the NCC was cordial and the City Engineer was very helpful, however, we were advised that answers to our questions on detail could be found in the consultant reports. The NCC does not have a position outside and beyond those contained in the reports. Therefore, to compare our opinions, we need to refer to statements and quotes within these reports. In other words whatever is in the reports is what s going to happen. (c) Design Presentation We found the information in the reports to be inconsistent with the presentation by the NCC. Refer to Beca Report clause 3.3 Refinement of the Preferred Layout quote: The main driver was to reduce the land erosion potential for the properties along Whakarire Avenue (see appendix I). Other than minor strengthening work on the 1994 seawall and some shoring work at the south end, this preferred option would not give the Whakarire Ave properties any further land erosion protection. Waves will have gone beyond these properties before the new breakwater will have an effect. The need for this breakwater is about repairing damage caused by a poorly designed seawall. Refer to Beca Report clause Preferred Option - refinement to the V shaped option have the following benefits: a higher degree of sheltering of the southern end of Westshore Beach and a better feeder area for the nourishment scheme and provide an optimal layout for the recreational beach (see extract appendix IV a). Firstly, the southern end of the beach was sufficiently protected by the Rangitira Reef until It was adequately sheltered and does not need a higher degree of sheltering to the protection that existed prior to Remove the ill-conceived seawall.

5 3 Secondly, Becas propose nourishment as a long term solution our opinion differs. Thirdly, within all reports, there is a brief to include a recreational beach we agree with this amenity but after the main assets have been made secure. Refer to Becas Report clause 3.2 Layout of Preferred Design. Here they state that the seawall (they mean breakwater) would encourage a sheltered area to be formed and it should form a crenulated shaped beach created from sand dredged from the Inner Harbour channel. Paul Komar Report page 26, states that nourishment taken from the estuary would not be expected to remain on the beach. The dredged material is finer than the estuary material which was unsuitable therefore these tailings would be worse. We provide photos exposing poor judgement by using this material where wave action exists. Refer Beca Report page 2 referring to dredged material quote: This material was observed to have moved rapidly to the north. The Councils position is as follows: beach erosion is under control, any loss of beach and seabed is cyclical, the Port breakwater is not responsible for erosion at Westshore, the material used for nourishment is suitable, the nourishment is a huge success and any money spent on beach protection is good for the community. Anyone who disagrees with the experts or has a different opinion is wrong. We disagree and provide the following information to support our differing opinion. The old saying put up or shut up. (d) Commencement of Erosion From approximately 1970, larger bulk cargo ships were arriving at the port and the Harbour Board had to ensure that they could stay in port to load and discharge during high seas with large swells. Enhancements to the breakwater and extensive reclamation to handle extra cargo (mainly logs) were commenced with urgency. Soon after, larger container ships and roll-on-roll-off ships required deeper berths and deeper shipping channels. This port development provided instant benefits for Napier city but from about 1980, a progressive problem for Westshore Beach developed. Beca Report state that the uplifted foreshore from the 1931 Earthquake coincidently lasted until about this time and without qualification quote: by the mid 1960 s the benefits of the uplifted foreshore area had diminished and the Westshore Beach system started to noticeably erode. We can only assume that such a statement is derived from the findings of Paul Komar and is at odds with the cover photo showing the beach sand content in The effects of breakwater works became evident in the late 1970 s and early 1980 s. The Port employed (jointly with NCC and HBRC) Paul Komar to convince the population that the Port was in no way responsible for Westshore problems. His report concluded that the forces of nature were at work. Residents had to accept this situation but still needed a remedy for a problem that did not have a tangible cause. Nourishment started in A close inspection of the cover photo will reveal the extent of sand built up on the beach. Note the boiler (black speck) in line with the south end of 3 Charles Street. Note the old freezing works concrete blocks are surrounded with sand. Note this photo taken towards low tide reef rocks are hardly exposed.

6 (e) NCC Engineers Position 4 An article appeared in the Hawkes Bay Today newspaper on 15 th July 2009 with quotes by NCC engineers that differed considerably to our understanding of the situation. quote - Paul Komar states in his report that there is no firm evidence that flows of material along the Bay had been disrupted by the breakwater or that it was responsible for erosion. quote - There has been a lot of consultation with the community. quote - The proposed breakwater and a beach will assist the (Westshore) beachfront and replenish it. We also had difficulty with reconciling the following statements that were made during our discussion with the City Engineer on 21 st October 2009 quote - The Council does not have concerns about erosion at Westshore Beach, any apparent erosion is cyclical and will be replenished quote - The new breakwater will not reduce the amount of material required for the nourishment programme. quote - The shingle material extracted from the Pacific Beach is suitable for nourishment because it holds in the beach on the Marine Parade and at Bayview, so why not Westshore. (f) Comments on the Komar Report The following statements are extracts from Paul Komars Report dated January Because the NCC and HBRC engineers refer us to this information we are limited to commenting on detail within this report. Our brief comments are based on opinion and local knowledge. page 16: The beach gravel that presumably continues to arrive from the south has not moved along the arm of the breakwater and entered the fairway navigation channel leading into the outer harbour behind the breakwater. Shingle built on the outer arm of the breakwater extension to form a beach. Also, if this statement was accurate, regular dredging of the channel would not be necessary. page 16: The erosion at Westshore has been relatively minor, and it can be accounted for by causes other than the breakwater. We do not agree that the erosion has been relatively minor. Evidence of serious erosion follows. page 17: The breakwater today permits the accumulation of larger quantities of sand at Westshore than found on the beaches elsewhere along this coast. We see no evidence of accumulation and our assessment is one way depletion. page 17: The shelter provided to that shore (Westshore) by the breakwater, protecting it from the storm waves that predominantly arrive from the southeast, has been a significant factor in having reduced the beach erosion and hazards from flooding at Westshore. Reduced erosion is not apparent and the reduced hazard from flooding is yet to be tested in a severe storm. See photos of damage by high seas during June 1997 (not a severe storm). page 18: Small quantities of beach gravel were able to bypass Bluff Hill prior to the breakwater s construction,.. there is no evidence for any bypassing having occurred subsequent to its construction. The build up of shingle at Bayview northwards is not all imported nourishment material that has drifted north and/or the build up at Tongoio is not from the Esk River.

7 5 page 22: therefore, on a daily basis there can be a reversing longshore sediment transport, sometimes to the north and sometimes to the south, but with the long term net transport being essentially zero. We agree that the sediment transport can reverse (to the south) but not on a consistant basis and never enough to suggest that the net transport is zero. The northerly drift is dominant. If, zero net transport was the case, we would still have a beach. page 25: There is certainty of greater storms in the future than experienced in recent decades, and an expectation of a more rapid rise in sea level during this century due to global warming. If the expectation is greater storms and global warming is included as a factor by the NCC and HBRC, then the urgency to do something other than nourish is considerably increased. page 26: Nourishment undertaken in consisted of silt and fine sand and would not be expected to remain on the beach. These estuary tailings damaged the upper beach and added to the erosion problems. The NCC Overseer was present when the material failed a traditional basic test for sand. page 26: The conclusion is that the nourishment programme has been a success. The sediment placed on the beach has moved to the north. Whilst we agree that something had to be done, we do not agree that the programme is a success. If the nourishment since 1987 was coarse sand (similar to the material that has been lost) the programme would have been beneficial. Suitable sand is unavailable and unaffordable. page 27: with the erosion and flooding hazards now largely under control along Westshore. We have big problems with this statement and find it optimistic and without foundation. (g) Comments on the Beca Report The following statements are extracts from the Beca Report dated April Because the NCC and HBRC engineers refer us to this information we are limited to commenting on detail within this report. Our brief comments are based on opinion and local knowledge. page 2: by the mid 1960 s the benefits of the uplifted foreshore area had diminished and the Westshore Beach system started to noticeably erode. The major changes to affect Westshore between the mid 1960 s and recent times are breakwater extensions and extensive deepening of the shipping channels. The 1931 Earthquake, responsible for the uplifted foreshore, produced a user friendly beach for close to 50 years. Erosion was not noticeable until about 1980 s. See timeline 1920 to page 5: This erosion is currently countered by the beach nourishment system which has largely been successful in alleviating erosion and which nourishes the beach with about 15,000 m3 per year from Pacific Beach. The average actual bulk measure delivered is closer to 12,000m3 per year. The current net loss (see calculations) suggests a nourishment deficit between 150,000 and 200,000 cu.m. page 5: Since the introduction of the Port of Napier breakwater system, natural inputs of sediment into the southern end of the Westshore Beach system have ceased. We agree with this statement but it conflicts with Paul Komars assessment. The above is from the clause Causes of Erosion and fails to make reference to the last 15 years when serious erosion was inflicted by the 1994 seawall. If the input of sediments has ceased, how can the NCC conclude that it is cyclical.

8 6 page 5: any sand or gravel that is introduced into the local beach system cannot hold its position because the waves drive the sediment northwards. We agree, hence the futility of constant nourishment. Coarse permeable sand would hold in the beach system longer Ocean Beach or Taits Beach sand is ideal but unavailable and unaffordable. Manufactured sand is simply unaffordable. page 13: Local rock is available of sizes required to resist wave attack, but generally it is not suitable for wave protection. Local rock is very suitable and affordable. See Proposed Breakwater Construction Material page 13:.. rock.. will need to be imported from out of the region. A suitable source of rock has been identified in Tauranga and Taranaki. Where there is moderate to high wave action, local rock is suitable. The quarries at Ngaru Valley, Seafield Road, Taits Tongoio, and Firths Pakipaki, produced heavy, dense limestone rocks. Longevity of seawalls is about construction method as much as it is about material. page 15: The hard rock will probably be barged to the Port of Napier or Ahuriri Harbour and offloaded into trucks and delivered to the site. The import of rock at $100 plus per tonne is a gross waste of funds. The Councils could save 80% on the cost to supply and deliver, then have a huge reserve for maintenance. Unfortunately, local body engineers often leave the maintenance unattended until repairs and restoration are required, as is the case with the Whakarire Ave Seawall and south end beach rock protection. CAUSE OF WESTSHORE EROSION (a) Effects of Severe Storms The storm experienced in 1985 caused enough damage to warrant a beach nourishment programme that started in This storm was moderate when compared to August 1974 when waves flowed over the beachhead, filled many areas of the reserve with seawater and left debris everywhere including parts the road. Fortunately at this time, the beach was in a state of accretion and there was sufficient sand in the inshore seabed and upper beach to limit the damage. Unfortunately the beach profile has altered considerably since 1974 and the area above the high water line will react very differently in a storm of similar magnitude. Wave height is one component but the extent of damage to the shore is dependent on the duration of the offshore storm as decided by Mother Nature. Her timing is unpredictable and always a reminder of who s in charge. The wall of Marine Parade gravel, called nourishment, will not and cannot hold its position in the beach system because the waves drive the sediment northwards (refer to page 5 of the Beca report). When this steep bank of pea metal is exposed to wave action, it collapses into a beach of rolling pebbles and enters the northerly drift. This type of material does not contain significant sand, is pea shaped, therefore cannot be compacted into a dense state of strength, and is particularly unstable in water. The beach is vulnerable to a severe storm and due to three factors. 1. The inshore seabed and beach gradient has eroded by at least one meter. 2. The crest of the original beach has retreated offering less resistance to HW surge. 3. Nourishment material is unstable and will not withstand extreme storm waves.

9 7 Damage and Flooding August 1974 Major damage was caused at the Port of Napier requiring an extensive clean-up operation by men and machines. Substantial protection work was undertaken in preparation of a similar storm. This work has not been fully tested because we have not experienced a similar or larger storm, however, the engineers would have learnt a lot from this experience. During the low tide peaks of this storm, we could only watch the devastating power of the sea throw huge rocks and concrete blocks around threatening to breach the breakwater at two critical points. At HW it was a case of standing back. These photos were taken on 18 th August 1974 from the top of the conveyor that feeds phosphate into the store. Waves were landing on the roof of the bulk phosphate shed. Fig 1 Storm 1974 with Bulldozer Fig Damage from 23ft Waves Fig 3 Comparison of damage from a Large Storm (not a severe storm) June 1997

10 (b) Breakwater and Extensions 8 Fig 4 Marine Chart Obstructions to Northerly Drift The dark blue shaded areas show depths from 0m to 5m and the light blue shaded area outlines 5m to 10m depth. The horizontal distance to the 5m mark, out from the inner breakwater extension is 70m. Other than rock on the edge of the construction, this area contains a large quantity of material (transported by northerly drift) that is destined to be deposited into the shipping channel and/or diverted to shallower water and transported further north. Again, this build-up of sediment and movement in a northerly drift conflicts with the Paul Komar report. quote: Small quantities of beach gravel were able to bypass Bluff Hill prior to the breakwater s construction,.. there is no evidence for any bypassing having occurred subsequent to its construction. Opinion: This appears to be a qualification of a preconceived conclusion. A Pacific Beach Groyne. The groyne at Pacific Beach interfered with the northerly drift of shingle. The scale model in A Shed did not factor in the eddy effect of wave action when it reacts to a structure that impedes the northerly drift. This groyne was demolished within days of completion. Fig Built and Demolished Fig Workshop Protection

11 9 Fig 7 1 st Port of Napier Impediment to Northerly Drift B C Breakwater Strengthening This work was to strengthen the original breakwater using unlocked interlockable tetrapods and an assortment of concrete blocks. This work was normal maintenance and the effect of this impediment has not increased during the intervening period. Protective Apron Damage Control During the 1974 storm, 10,000 plus tonnes of limestone rock were placed to strengthen the outer side of the breakwater and the resultant gradient change interrupted northerly drift. The engineers wanted the largest rocks possible to strengthen the breakwater. 30 tonne rocks were pushed onto Low Loaders with a Cat D9G at the quarry and pushed off at the breakwater with another Cat D9G. Every available local concrete truck was used to pour quick set concrete into the gaps of the breakwater. This exercise turned the water into an interesting colour. Fig 8 Extract from Port & People D Breakwater Extension The extension with the angled groyne (now realigned) deflected the shingle drift and directed any gravels passing the breakwater to transport sediments further north towards Bayview and Tongoio (via deeper water). Refer Fig 9 and Fig 10 below.

12 E Seawall Inner Arm 10 Shingle passed beyond the end of the breakwater and accumulated on the seaward side of the arm on the outer log area seawall. A beach of grey wacke shingle was clearly visible at LW on the eastern side of this Inner Arm. A photo showing this build up is on Google Maps but we are unable to sort out a way of downloading it at this time. This beach was visible by sea and air plus to those allowed at the end of the breakwater. As shown in per fig 10, this beach has now been reclaimed and the material now heads to the shipping channel or out to deeper water for transport to Bayview and north. F Seawall Extension The realignment and extension of the log pile reclamation deflected the shingle away from Westshore Beach to places northwards. This structure will ensure that starvation of sediment will remain and erosion at Westshore is irreversible. Fig 9 Breakwater with Arm Fig 10 Breakwater Log Store (c) Shipping Channel The material that makes its way beyond the breakwater accumulates in the excavated shipping channel. Unless this channel is allowed to overflow, the northerly drift of coastal sediment ceases at this point. The material is dredged to barge transport and dumped beyond the 5 meter depth where it can drift to Bayiew Beach and beyond. Westshore Beach is starved of replenishment material during this regular Port of Napier operation. Every cubic meter of shingle dredged from the fairway is a cubic meter of replenishment material that cannot and will not make it to Westshore Beach. (d) East Pier Mole Large quantities of shingle were removed for reclamation from the beach at East Pier. This site was convenient and the extraction was a simple operation with a Front End Loader. The build-up slowed to a virtual halt by about 1980 with the only change to the environment being, extensive breakwater development. Extraction ceased during the 1980 s. Every cubic meter of shingle removed from here was a cu meter that did not make it to Westshore Beach. The accretion of this beach has ceased due directly to the breakwater extensions and excavated depth of the shipping channel. Therefore the East Mole and West Mole are no longer effective impediments to the northerly coastal transport of sediment.

13 11 Fig 11 East Pier Shingle Pit Fig 12 Chart East Pier Bayview and Tangoio Beach These beaches are in a state of accretion and have three sources of replenishment: 1. Nourishment material imported to Westshore Beach is transported to these beaches by the natural northerly drift of coastal sediment. 2. The coastal sediment that makes it way beyond the breakwater impediment, is deflected by the latest seawall extension, transported across the channel in deeper water and deposits to these beaches. 3. The dredged material is towed in a barge and dumped in areas where the northerly drift will replenish the beaches between Bayview and Tangoio. Replenishment with dredged to barge material has not been successful at the south end of the Beach. (e) Starvation of Coastal Sediment The replenishment material is transported via the HB rivers to arrive south of the breakwater. This is the main impediment for material to continue in the northerly drift. The contributors to less shingle arriving at the river mouth included numerous shingle screening plants, direct river extraction by contractors for building and road works, major extraction for the Napier-Hastings motorway, high demand for railway ballast and large orders for road and concrete aggregates trucked out of the district. The demand on this resource peaked between the 1970 s and the 1990 s. A minor contributor to the current starvation of material was the shingle screening plants needing large stone for crushing and sand for concrete aggregate. These plants yielded large quantities of pea metal from the 3/8 screens. This material was dumped back in the river (downstream) or sold to the Port of Napier as royalty free waste and used for reclamation. This dumping in the river caused further yield problems at Awatoto but after the large stone is screened out, the pea metal joins the northerly drift and arrives at Marine Parade as smaller pea metal or sand. This is why contractors prefer to work an untouched beach to yield a larger stone size. These past and present practices account for the lack of large stone in the current coastal sediment system.

14 CURRENT WESTSHORE EROSION 12 (a) Seabed Gradients This chart compares the Westshore profile with Marine Parade and Bayview profiles to support our view that pea size and pea shaped gravel is unstable. The material cannot be washed by wave action from an embankment at 1:1 slope and remain in the wave zone on a gradient of 1:150. The retention of this material on the beachhead is dependent on replenishment material on the seabed. The stability is relative to the availability of material within the wave zone which allows shore wash to permeate down and back. This action lessens the scouring effect of backwash and produces a steeper upper beach profile. The abundance of permeable gravels on beaches exposed to the ocean tends to have a dumping wave action with undertow. The critical difference at Westshore Beach. Fig 13 Beach Profiles Marine Charts (b) Erosion at Boiler Fig 14 Fig 15

15 13 Since 1972, the high water mark is closer to the road and erosion has consumed 30 odd meters of accessible beach. However, the low water mark was meters on the seaward side of the steam boiler but has been eroded back to the base of boiler, as shown below. These photos are from a 1.50 meter tide and were taken on 20/10/09. Fig 16 Boiler 2009 LW Fig 11A - Boiler at Low Tide 1972 Fig 17 Boiler at Low Tide 2001 Fig 18 Boiler 1993 Fig 19 Boiler 2009

16 14 We estimate that the sand at Kiwi Beach has eroded in height by approximately 1.2 meters. The estimated beach level in the 1970 s is based on the lower part of the boiler dome towards HW was covered with sand at that time. The bottom support on the dome has rusted away and the cylinder casing has dropped in the last 5 years. The miniature black mussels, still visible today, were encrusted below the HW mark. Children could scramble over this boiler and photos were taken of bathers posing on top. The boiler is not from a ship wrecked steamer as most people have been led to believe. This type of boiler is not used for marine applications and is thought to have been discarded from the freezing works when they were demolished in The boiler could have embedded itself into the beach to some extent but essentially the sand had built up by 1.2 meters over the ensuing 50 years of accretion. If this boiler has settled further into the beach by wave action, then our assessment paints a worse picture. We can safely assume that it has not lifted. 50 years of sand accumulation has been lost in 30 years. (c) Gradient at Boiler Fig 21 Boiler 2003 Fig 22 Boiler 2009

17 (d) Loss of Beach Sand 15 Fig 23 Estimate of Beach Erosion The above beach profile is shown with a distorted horizontal to vertical scale using LINZ depths at Kiwi Beach. By using average measurements, the quantity of erosion takes Kiwi Beach as worst case with all measurements reducing to zero. The calculation of 150,000 cu meters of sand erosion is based on minimum measurements with a 20% allowance. We make this allowance because, at this time, we do not have a photograph showing the exact sand level in the 1970 s. (e) Erosion at Kiwi Beach During the 1970 s, this area was completely covered in sand (see 1972 cover photo) and was our regular family picnic area. We could sit with our backs to the blocks and have our children play on the sand in front of us. The earlier sand level is evident by distinct colouration at the base of the concrete blocks. The large boulders and the jagged timber piles have been exposed since the seawall was built. Fig 24 Erosion at Blocks Fig 25 Eroded Picnic Area

18 16 Fig 26 Erosion at Kiwi Beach Fig 27 Erosion at Concrete Blocks (f) Erosion at South End This area has been subjected to dramatic changes following the construction of the seawall in As seen in the 1972 cover photo, this area was full of sand and was a haven for basking scate and/or sting rays. The waves are refracted by the seawall and follow the line of the old seawall. The waves create an eddy effect and this had eroded the fine sand that had deposited in the south end corner between 1931 and Fig 28 South End Erosion Fig 29 South End Backfilling

19 (g) Rocks Removed by Public 17 The beach at the south end has been targeted by landscapers who regularly hand pick rocks for removal. Whilst the tonnage would not be huge, any removal of beach protection in the absence of replenishment is not ideal. We asked the NCC why the constant depletion of these rocks has not been replenished since the beach protection works in 1894 (115 years). The response attached outlines a proposed rule 136, where it mentions sand and gravel but fails to make a distinction between gravel and rocks. As this activity is well known to the NCC, we would expect some sort of monitoring of any introduced coastal protection works. As an adjacent neighbour, we have no wish to police this activity but would welcome some overdue maintenance. A 100 tonne of cobbles would keep the gardeners going for another hundred years. (refer Appendix II) Fig 30 NCC Answer to Rock Removal (h) Erosion at Beachhead The nourishment programme is administered by the HBRC and the engineers accept that the beach will continue to retreat, as per statement below. The original road does get exposed each year following moderate storms but the covering up is done after a section of the road has disappeared. The engineers must have a point in mind when this somehow accepted constant retreat of the crest becomes unacceptable. As a resident opposite the beach, we would be very keen to know this point. Becas Report clause 3.2 quote: If Westshore Beach were to retreat to Charles Street, the new sand beach and the properties on Whakarire Avenue would be protected although some public reserve would be lost. It therefore provides a robust solution for property protection. This statement is totally unacceptable. Is the acceptable limit of erosion at the kerbside or middle of the road. The combination of a severe storm, an eroded beach gradient, and a lack of forward planning could inflict unacceptable damage overnight. Extract from the NCC letter following my meeting with the Council engineers.. (Full letter Appendix II) Fig 31 Extract on Crest Retreat

20 18 Fig 32 Erosion of Beachhead 2009 Fig 33 Erosion at Old Road 2009 Fig 34 Erosion of Beachhead 2009 Fig 35 Embankment over Tree Stumps 2009 (i) Condition of the Beach Residents have had to suffer the near total loss of usable beach at high tide, unreasonable access to the beach, the poor aesthetic value of the shingle embankment, and the fact that each year the crest of the nourishment mound is getting closer to the road. The consultants, the Council engineers, the Mayor, the local newspaper, The Westshore Residents and Development Association and even some beach front property owners are claiming that the annual nourishment is a huge success. We are at odds with their perception and acceptance of inferior options. Fig 36 Before Nourishment 26/09/09 Fig 37 - After Nourishment 20/10/09 A sample of quotes by Ratepayers and residents include: The state of this Napier and Hawkes Bay amenity is disgusting and The appearance of the beach following annual nourishment as disgraceful and Access to the beach for the elderly and less agile is impossible and the persons responsible, should be ashamed.

21 PROPOSED BREAKWATER 19 (a) Design H Shaped Option (b) Recommended Design Fig 38 Breakwater Upgrade August 2009 Becas produced 11 designs and variations (not counting the do nothing option) to solve one problem. That problem was to rectify the damage caused by the 1994 seawall which was built without due regard for Newtons Third Law To every action there is an equal and opposite reaction. We are interested in Beca s assessment as to where, between Tareha Street and the Surf Club will this diversion of energy show up as the reaction. The following designs were presented in April It is obvious that this is not an exact science but providing 12 options with the odd should and could is cause for concern. 1. Option 1 - Enhanced Seawall Remove Concrete Blocks 2. Option 2 - Enhanced Seawall and Infilling of Backshore Remove Concrete Blocks 3. Option 3 - Groyne to Limit Wave Focusing Seawall Option W3 4. Option 4 - Wave Spending Beach New Groyne at Concrete Blocks 5. Option 5 - Attached Breakwater with Beach Creation Remove Concrete Blocks 6. Option 6 - Do Nothing Option 7. Option 7 - Attached Breakwater and Offshore Island Remove Concrete Blocks 8. Option 8 - Preferred Alignment - Version 1 - Northern V-shaped Breakwater 9. Option 8 - Preferred Alignment - Version 2 Southern V-shaped Breakwater 10. Option 8 - Preferred Alignment - Version 3 Original Proposed Breakwater 11. Option 8 - Preferred Alignment - Version 4 Rotated Breakwater 12. Option 8 - Preferred Alignment Version 5 - Combination of V-shaped Breakwater

22 20 Fig 39 Upgrade 20/08/90 Fig 40 Option 20/05/09 Within 3 months, the 1st major upgrade to the 5 th version of the 8 th option was released as shown (fig 39 and fig 40) with an entirely different shape and with the angle of inclination altered by 7 degrees to the north with approx 50m added to the length. This upgrade will produce a reaction to refracted wave energy to an area north of Kiwi Beach. We predict that North Terrace residents will become very interested or seriously concerned when this reaction point becomes obvious. The resultant damage may take some years to become evident. We have had to endure repeated references to the expertise of the consultants and any contrary opinion is without credibility. In the past, we have employed and worked for many engineers and found them capable of overlooking problems and getting remedies completely wrong. To support this statement we will share just one experience. An engineer at the Port purchased a bottle of Coke, poured it over a sea salt rusted nut on a 1¼ bolt in an effort to remove a cast iron bollard at No.5 wharf. Our unqualified opinion after years of civil engineering contracting on marine projects is if you are going to play around with the variances of the seashore, you need to do a lot more than read text books and experiment with models. (c) Purpose of Breakwater Becas Report page 6 clause 3.1 quote: The do nothing option found that Whakarire Ave would be eroded without protection works and that the existing seawall was likely to fail in a significant storm. This qualification on the do nothing option is baffling or misleading. If the 1994 sea wall was raised and had a few voids filled, then the Whakarire Avenue properties would be just as secure as they have been during the last 115 years. With this minor work along with south end maintenance, not a single Whakarire Avenue property could attribute protection to this proposed seawall. Based on the current state of Kiwi Beach, the properties that are more likely to be eroded in a do nothing option are those in Charles Street between the south end and Nott Street.

23 (d) Damage Caused by Seawall 21 In terms of long term damage to the south end of Westshore Beach, the seawall built in 1994 was a disaster. It addressed the erosion problem for the Whakarire Avenue properties but redirected wave energy to another point of the beach. The resultant damage is clearly evident and Becas concede that the concentration of wave energy caused a rapid loss of sediment at the southern end (see quote). Unfortunately, when a seawall does not work, it is not a simple task to remove it. This seawall was built using trial and error and, presuming it was not a calculated risk, the error component took 10 odd years to show up the damage. Instead of simply strengthening or maintaining the protection that had worked for over 100 years, the Council opted to include extra works to extend a city reserve. The pond formed during construction has slowly filled with fine sand. This sediment was suspended in storm wave wash and has settled in the surge protected pond. The intention was to backfill this area, grass it, call it a reserve, and provide another community amenity. This was a very, very expensive exercise that went horribly wrong. Becas Report page 16 clause 5.2 quote:..waves then propagate along the existing seawall and concentrate wave energy on the southern end of Westshore Beach. This...has caused problems with rapid loss of sediment imported for the beach nourishment scheme. Becas concede the damage caused but seem unaware of the severe erosion in the south end corner. The wave action created by the seawall is refracted into the south end as shown below. Refer to Fig 28 and Fig 29 for further evidence of this erosion. Also, Becas Report page 6 clause 3.1 quote: In an attempt to arrest erosion, a rock seawall was constructed in Whilst providing some level of protection to the existing coastline, it is not considered robust enough The shortcomings have to be inadequate design or poor workmanship or both. The area from the south end of Whakarire Ave to the concrete blocks is protected by imported rocks. Not a single stone has been placed in this area since The rocks are no longer embedded in sand because the 1994 seawall has refracted waves and eroded sand northwards. This area is particularly vulnerable. In certain sea conditions, the wave movement over these exposed rocks have denuded the sand and put excessive erosion pressure on a shoreline that was previous secure. The properties directly opposite exist as surveyed sections prior to 1873 but directly due to this ill conceived seawall, are now at severe risk by erosion according to the CHZ. The land values have been decimated. Fig 41 South End Wave Refraction Fig 42 South End Erosion

24 (e) Breakwater Construction 22 Becas Report page 13 clause quote: : Local rock is available of sizes required to resist wave attack, but generally it is not suitable for wave protection plus :.. rock.. will need to be imported from out of the region. A suitable source of rock has been identified in Tauranga and Taranaki. We totally disagree these assessments. The majority of seawall rock was sourced from a Seafield Road quarry and Taits farm at Tongoio where predominantly hard dense limestone rock was supplied. The Port engineers were indifferent about porous rock and on occasion accepted them as more stable under water. The theory was, they stimulated sea plant growth, the surface was sealed from wave action and the rock tended to remain in place. We delivered tonne boulders during the 1972 storm and placed them seaward of the breakwater at LW. Two of them were sitting on top of the breakwater following the next high tide. Suitability of rocks can differ between seawalls and breakwaters and exposure to direct or indirect wave energy determines size for stability. The engineers are comparing rock work carried out about 40 years ago to what is achievable today. Construction methods have a lot to do with the success or failure of a breakwater. Voids and rock settlement are an unavoidable component of this type of work. During the 1970 s, the best machinery available for placing rock was a wire rope controlled rock crapple which relied on gravity for downward pressure and placement. During the construction of the Waimarama seawall we used one of the first chain driven hydraulic diggers, not designed for this sort of work and a little light but at least you had side and down pressure. Currently there are heavier hydraulic machines with numerous attachments which remove any operator excuses for not locking in each rock, above the low water mark anyway. Fines and loose small rocks are unacceptable on the seaward face of a seawall or breakwater. A machine operator with masonry skills is an asset. (f) Formation of Sandy Beach The comparison made with the Hardinge Road beach could be limited to appearance only. The Hardinge Road beach had little to do with build-up from coastal sediments (naturally occurring or imported filling). This area was one of the first areas reclaimed by the then, Harbour Board for log storage. The material used to form this area was from the first and second earthwork contracts at Hornsey Road (current site of Port Coolstores Ltd) and excavated material from the base of Bluff Hill between Coote Road and Hornsey Road. Because this end of the reclamation was protected from waves, the material was dumped and bulldozed level until the next load arrived. There is a small amount of sediment deposited by wave action, but the beach is predominantly material that was trucked to the site from the Bluff. The main clue is the colour of the beach material. At that time, hard demolition rubble, smashed concrete power poles, etc was used on the seaward sections to limit erosion of the fine infilling because quarrying for limestone rock in bulk had not been established.

25 Dredged Material for a Sandy Beach 23 The suitability of this material has been covered earlier in this assessment. The material is super fine, it is unstable in water and cannot maintain a gradient. It contains live cockles and broken shells, the material contains organic matter and retains an undesirable smell. When dry, it turns to fine powder and the prevailing westerly winds lift clouds of dust away from the beach. This material, at one time, was held in suspension by tidal flows and considered best suited on a level seabed. This material is not user friendly on a beach. See Beach Nourishment clause (a) Material from Estuary it is similar material held in suspension until flow is reduced to deposit it in the inner channel. Promoting a Breakwater with a Sandy Beach Becas Report quote page 17 clause 6: : A new recreational beach (at Westshore) will provide amenity value to the community We would be absolutely delighted if a sandy beach was formed opposite our front door. Realistically, we would prefer the funds that have been put aside for this project, be allocated to a long term solution. The most prudent decision would be to commit to a solution that removes the risk of major damage. The next project would be restoration of the upper beach then followed by the formation of a new recreational beach. The building of a new beach, at this point, is a reckless use of funds when resources are desperately required to save a beach, a reserve and City infrastructure not to mention the risk to private property. Estmated Cost of New Breakwater Project The HB Today article (appendix II) has the estimate at $4.50M, however, the NCC Engineer insists that the project is only $1.60M with incidental costs that would be borne by the City Council anyway. We cannot get an explanation for this difference. (g) The Northerly Drift at Westshore

26 BEACH NOURISHMENT 24 (a) Material from the Estuary Paul Komar Report page 21 quote: Nourishment undertaken in consisted of silt and fine sand and would not be expected to remain on the beach. This material was estuary tailings mixed with gravel and a mix of super fine sand. This sludge material did more damage to the upper beach and accelerated the erosion problem. The NCC Overseer, on site in 1987 was informed of our concern when the material failed the basic test for sand. A sample was rolled in the hands to a sausage shape, clasped in one hand and released sand collapses, and mud stays intact. At one time, this test was accepted practice to introduce provisional sums for unexpected ground conditions. The relationship between the gradient of the beach, the size of the wave impediment, and whether the beach is in a state of accretion or depletion is covered earlier in this assessment. Bioresearches Report dated July 2004 page 34 - Samples taken and tested by Mr S.E. White M.Sc (Hons) described this material as slightly gravelly sandy muds. Any material containing mud (wet or dry) is unsuitable in a wave zone. (b) Material from Marine Parade Paul Komar report page 25 quote: : It is estimated that of the original 90,000 cu meters per year of sediments being transported (from the Haumoana cell) into this northerly stretch of shore, only about 6,000 cu meters reaches the Napier shore (Marine Parade) each year, and it could very well be less than that. If this was the case, then annual nourishment extraction at Pacific Beach will cause serious environmental concern if it continues. HBRC removes 15,000 m3 and with this input of 6,000 m3 or less leaves a deficit of 9,000 to 10,000 m3 per year. The Marine Parade has been the material source for 15 of the 22 years that nourishment work has been operating. The deficit of 135,000 cubic meters of shingle at this beach would be very, very obvious. Paul Komars statement is either unbelievable or late notice of an environmental disaster in the making. The Pacific Beach material is unsuitable for a depleting beach where the gradient of the beach and seabed has been lowered and the high tide mark is below the beach head. The condition of the beach, as shown below, is the result of moderate to high seas experienced in the last 12 months. No severe storms were experienced during this time. The trees as shown in Fig 43, could come into full view following an extreme storm. Replacing the 150,000 cu meters of lost sand with Ocean Beach, Taits Beach or manufactured sand is not practical or affordable. The current nourishment material is weak and simply gets flattened in extremely high seas. Therefore, should this material continue to be used simply because it is convenient, cheap, or saves the Port dredging it from the shipping channels.

27 25 Fig 43 - Nourishment The material above the concrete blocks has and will do absolutely nothing to control erosion in an expected severe storm. It is an example of reckless totally inappropriate engineering practice. We were thankful when the ridiculous topping with silt and grassing was stopped following strong pressure from locals. It is a gross injustice when so called public servants can enter your neighbourhood and make such an unnecessary and blatant mess every year. (c) Material from the Inner Harbour Becas report page 6 clause 3.2 quote: Depending on grain characteristics, the new beach could be created from sand that is infrequently dredged from the Ahuriri entrance channel. The merits and suitability of dredged material from the Inner Channel has been covered earlier. We had firsthand experience with this powder sand and fortunately did not have to put up with the stockpile in front of our home for long. What did get blown away was washed away rapidly. The uses for this material are in line with its origin suitable for raising a seabed in an area without wave action. The real concern is the comment by the NCC engineer quote: this material is fine and there is no reason why it should not be used on the beach. We appreciate that his position is tied to the reports. (d) Nourishment Programme If material is introduced to the beach to replace material that has been lost it is called nourishment. If nourishment with different grain characteristics cannot hold its position then it is called unsuitable nourishment. If this material cannot be placed in the beach system and needs to be stockpiled then it is called an embankment of unsuitable material. If embankment material gets washed by waves above HW and gets driven northwards then it is called a huge success. If this success is repeated every year it is called a nourishment programme how can a layman not get this.

28 CONCLUSIONS 26 (a) Responsibility for Damage Paul Komar Report page 28 quote: It is time to put aside the placement of blame on the construction of the Port s breakwater. Without fudging, there is overwhelming or sufficient evidence to suggest that the Port of Napier is responsible for the problems at Westshore. The HBRC owns the Port so the argument can and should be put aside, providing the HBRC accepts responsibility for the repairs and restoration work. The funding of such work should rest with the culpable party and the NCC ratepayers will then be relieved of the unfair burden that the Council has voluntarily carried for years. The willingness of the Council to accept this ongoing liability for resultant damage by another party has been a dereliction of duty on behalf of the Napier City ratepayers. Westshore Beach has degraded into an unsightly state with very limited use as a community amenity. The HBRC should give urgent attention to a long term solution by controlling the erosion and restoring some aesthetic value to the area. (b) Alternative to Nourishment Sometime soon, nourishment at Westshore Beach could cease. It will stop because authorities will recognise the exercise as futile and/or the residents will not put up with the disgusting embankment along the beach and/or demand will build for a better and more responsible option. We do not agree with the consultants who state that the Marine Parade is a diminishing source of shingle however, whilst the reserves of seabed shingle are huge, we do not support using this material to control erosion. Many genuine ideas and calculated alternatives have been put forward over the years as certain remedies to rectify the erosion problem. Recently we were told by a retired engineer that removing the concrete blocks adjacent to James Street would solve all the problems (because he watched the waves at high tide). Offshore reefs of different sizes and groynes of varying lengths have been suggested but one vital ingredient has always been missed and that is the lack of replenishing sand and gravel. It is impossible to accumulate sand on a beach when the source of the sand has been redirected elsewhere and any manmade structure in open water will merely increase the problem. The alternative to nourishment and building a new breakwater is a long term solution that addresses the whole erosion problem. The remedy must satisfy the NCC, the HBRC and all stakeholders in the district. An actual line in the sand has to define an area where property will be protected from permanent loss and on the seaward side where the forces of the sea will have control. The line of property defence has to be a 3 km local limestone rock seawall. This could be built in two stages and/or with different profiles. There will be resistance from the NCC engineer because he has stated publicly that solid structures do not work. The NCC engineer has also stated publically that there is no serious erosion and nourishment is a success in accordance with the reports.

29 (c) Current Westshore Situation Coastal sediment has been interrupted by the Breakwater and Shipping Channel. 2. Beach replenishment material is not being transported by the northerly drift. 3. Westshore Beach was in a state of accretion from 1931 to mid 1970 s. 4. Approx 150,000 m3 has been permanently eroded from the beach and seabed. 5. The 1994 NCC seawall has accelerated erosion from Whakarire Ave to the Surf Club. 6. Erosion at the southern end is also due to inadequate rock protection maintenance. 7. The nourishment programme has been unable to keep pace with erosion. 8. The significance of the 1931 earthquake uplift to erosion is an erroneous conclusion. 9. The erosion is irreversible and nourishment is inappropriate and unsustainable. 10. A sand and shingle beach at Westshore is now impractical and unaffordable. 11. The new breakwater is more about containing seawall damage than land protection. 12. A seawall has to be constructed with urgency due to the weakened beachhead. (d) Long Term Solution The ideal solution could include: 1. Remove the inappropriate seawall at the northern end of Whakarire Avenue. 2. Strengthen the seawall into the south end on the same alignment as pre Shore up and maintain the beach between the south end corner and the blocks. 4. Ensure adequate protection for the heritage concrete blocks near James Street. 5. Excavate a trench below low water mark and construct a 3 km rip rap rock seawall. 6. Backfill the land side and build a concrete apron and call it the Shoreline Pathway. 7. Build a wave deflector wall on the apron to deflect wave wash to protect the reserve. 8. Beautify the reserve with the knowledge that the next severe storm will not wreck it. 9. Put a maintenance programme in place to guard against failure during a severe storm. 10. Provide 5% of rock placed in an accessible stockpile for short term expected R&M. This work is basic engineering and simple contracting: A 3km seawall containing rock at 50 tonne/m = 150,000 $20/tonne = $3.0 M Earthworks and incidental construction costs = $0.7 M Compliance costs and engineers charges = $0.8 M Providing the engineers do not over design for a hurricane Total Cost = $4.5 M A fair comparison, factoring in that it was 30 years ago, could be our unsuccessful bid of $120,000 to build the Waimarama seawall and a just by the way note that we supplied limestone rock to the Port for less than $4.00 per tonne from mid 1970 s to 1980 s. The erosion at Westshore is irreversible and the popular beach, as locals remember it, has been lost forever. Because locals have no choice but to accept this loss, they are entitled to a permanent practical and affordable solution. The others that will benefit from this project would include; the surfies, the marine life gatherers, the rock fossickers, the greenies, the shoreline walkers, the bike riders, the hard working reserve caretakers and the sunbathing stingrays.

30 Appendix I

31 Appendix II

32 Appendix IIIa

33 Appendix IIIb