On Friday, Councillors Barker, Beaven, Graham and myself offered an alternative dam proposal that we believe is superior to the $300 million scheme (plus another $300 million in on-farm costs) advocated by HBRIC and five of our HBRC colleagues.

As argued in the proposal, we believe our approach reduces key risks inherent in current HBRIC scheme, while still accomplishing the key goals intended for water storage at roughly half the cost, and therefore deserves public consideration.

In my view, our more affordable proposal poses less risk to the environment, because both the effectiveness of the new water quality safeguards and the actual reliability of dam water supply would be established in practise before unconstrained farming intensification was encouraged.

As Councillor Beaven said in releasing the proposal: “Water storage is critical to the Bay’s future. This alternative option reduces risk to ratepayers and gives us a lower cost opportunity to grow the region’s economy.”

Our proposal is pasted in below and attached here as PDF.

As you will see, we are asking HBRIC’s assistance in fully vetting our alternative. Our Council has spent nearly $20 million attempting to make a case for the silver bullet some believe will transform Central Hawke’s Bay into a Garden of Eden. Surely ratepayers deserve a careful look at a reasonable alternative.

We will seek Council support for vetting our proposal at upcoming Council meetings this month. So far, HBRC Chairman Fenton Wilson has not yet made a public comment. However, HBRC/HBRIC did manage to make same-day delivery of our proposal to Irrigation NZ chief executive Andrew Curtis, who immediately dismissed it as “naive”, even though it is built upon core aspects of the HBRIC scheme.

As Councillor Barker describes: “This proposal is an affordable two-stage option. The first, for this generation to build the dam that will protect the Tukituki, while providing significant increases in irrigation capacity for economic growth. And the second, leaving a platform for a future generation, should they chose, to make a similar-sized, second-stage investment in the more efficient but costly piping system.”

Councillor Graham sums up our goal: “We need to find a commercial solution that allows our farmers to successfully manage their business’s in harmony with the environment.”

Stay tuned.

Tom Belford

The right dam

A proposal from Councillors Barker, Beaven, Belford and Graham

We have consistently endorsed water storage as a prudent strategy for enabling Hawke’s Bay to better manage its water to meet the equally important challenges of mitigating impacts of climate change, improving farming productivity, and protecting the environmental integrity of our rivers and aquifers.

We do not believe the dam scheme presently proposed by HBRIC is a defensible response to that challenge, for reasons we have consistently raised, including its pricing of water at 26 cents per cubic metre.

Therefore, today we offer an alternative water storage proposal for the Tukituki catchment.

Our proposal, still in development based upon expert advice as to detail, has these main features.

1. Initiating a programme to actively support, including financially, farmers in the Tukituki catchment who wish to improve their own on-farm water storage capacity and water use efficiency. This would include support for on-farm dams, improved irrigation technology and use, and improved soil management approaches.

2. Building a dam on the Makaroro, much as presently proposed, utilising the engineering work completed to date as the basis of planning. This would include the electricity-generating capacity now contemplated, and potentially enhanced.

3. Using the stem of the river as the irrigation channel instead of building the extensive and costly distribution infrastructure currently proposed by HBRIC. Farmers more distant from the river on the Ruataniwha Plains could still draw water from the aquifer. Whether from the aquifer or from surface water, such extractions would be compensated by dam water released back into the river. This approach could serve the bottom part of the Tukituki as well as the Ruatanwha plains area. In contrast, the distribution infrastructure HBRIC proposes effectively doubles the cost of the project but provides no extra water.

4. Farmers using irrigation water would pay for that water, but at a far reduced rate – we anticipate half the rate or less – from that projected by HBRIC’s current proposal.

The advantages of our alternative proposal are:

  1. Costs are reduced by approximately half. The dam alone is estimated by HBRIC to cost $140 million (distribution infrastructure is estimated at about an extra $135 million – this amount would be saved).
  2. Reduced maintenance and operating costs, because no distribution pipework involved.
  3. No outside investment with high commercial returns required – project could be funded by HBRC and the Crown. Better cash-flow for HBRC – no costly returns for commercial investors.
  4. Cheaper water – less than  half the current proposed HBRIC price. At full uptake of 93 million cubic metres water at $0.10 per cube would generate $9.3 million. Sufficient to generate a return on Council’s investment of $80 million plus repay the Crown, when added to electricity revenue, next point.
  5. Greater power generation because no water diverted into a distribution system or used to pressurise the water. Revenue from power generation is estimated at $3 million.
  6. Greater environmental benefits from significantly increased water flow in the Tukituki. HBRIC in fact has indicated that a smaller dam holding 10 million cubic metres of water and costing $30 million would be sufficient to ensure environmentally needed minimum flows and offset the economic constraints of Plan Change 6. We propose building storage capacity up to the amount originally proposed.
  7. Better opportunity for farmers and growers in the lower Tukituki catchment. Our scheme would result in more water being available throughtout the catchment, including downstream.

This approach is prudently future-proofed in three critical respects:

  • First, operating in this fashion would allow time for Plan Change 6 to gain traction and, importantly, to indicate whether the environmental requirements of that Plan were: a) being met; and b) sufficient to protect the Tukituki ecosystem, before potentially unconstrained intensification of farming in the catchment was encouraged to proceed.
  • Second, similarly, operating in this fashion would allow verification of the actual water collection and storage capacity of the dam over time. Dispute exists over the actual quantity and reliability of water flows in the Makaroro and whether these are adequate to deliver the volume of water HBRIC current projects selling. Our alternative allows the system and its recharge capacity to be tested. If it proves lower than HBRIC estimates, it would still generate a fair return on investment for HBRC.
  • Third, assuming these two conditions were met and the scheme is successful in getting sufficient farmer support to commence, a distribution system could be considered as a future additional investment.  If sufficient demonstrated farmer demand for irrigation water developed and could be managed, at a future point the building of distribution infrastructure could be re-assessed, on the basis of water-user (not ratepayer) willingness to invest and own.

We are requesting staff and consultants support to flesh out the feasibility details of this alternative proposal, including re-pricing of water and alternative financing options.

At issue is a $600 million public/private investment that is projected to have a 100 year life benefitting Hawke’s Bay. Given the magnitude of this investment and its huge environmental and economic stakes and risks, we think it only prudent that Council consider a no frills alternative that provides water at a more viable rate. We do not need to hurry this decision, nor make it in a vacuum with the only one option presented so far.

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5 Comments

  1. I totally support water storage and agree with “water storage is a prudent strategy for enabling HB to better manage water” but I am not convinced with “water storage is CRITICAL to the Bay’s future”. My concerns are for the wider environment so I am very interested in some detail for “the proposal poses less risk for the environment” and “the alternative option reduces risk to ratepayers”. Hopefully the “new solution being in harmony with the environment” considers the wider consequences for HB’s gravel coast.

    My submission #136 to the BOI was judged irrelevant because it related to issues beyond the Tukituki River mouth. My submission #125 to the HBRC (Proposal to Invest) was disregarded because the agenda was already in place. Along with many other submitters, the HBRC responded with a standard bulk mail-out with a list of 10 pre-determined resolutions. Not a single engineering issue or concern was addressed. The HBRC submission process was purely a Council obligation and an insult to those prepared to make an effort.

    Basically, according to HBRC documents, the current proposed RWSS will block 42% of the erodible area in the Ruahine Ranges where gravel is sourced. Damming the Makaroro River will impede a significant supply of gravel and reduce flood flows in the Tukituki River which transports gravel to the coast.

    According to Prof Komar, any interference to the amount of greywacke stone and sand entering the coast will have a detrimental effect on the state of accretion and stability of the beach barrier ridge between Clive and Tangoio. The HBRC accepts the Dam will contribute to coastal erosion and have a scheme to mitigate damage. The plan to move meagre volumes of gravel, upstream of Black Bridge, to beaches adjacent to the river mouth is counter-productive or “robbing Peter to pay Paul”. Good for promotion but a futile exercise.

    Napier City Council put in submission #62, fully supporting the Dam providing boxes were ticked in terms of the environment. This half hearted “dollar each way” submission was made with full knowledge of potential risks. Reduction of gravel that supplies Napier’s entire eastern boundary will advance beach erosion and affect property and infrastructure. The next Council must take an interest in the security of valuable assets along and behind the Marine Parade.

    The four wise Councillors are well positioned to get action. It’s difficult to convince single minded Councillors that there is a better cheaper option and the environment does not need to suffer. In my case, Napier City Council was asked to consider a better cheaper coastal erosion solution at Westshore Beach. It took a frustrating 5½ year battle and a HBRC consultant to convince Council an offshore breakwater at Whakarire Ave was problematic and extravagant. Finally, overdue maintenance, strengthening the existing rock seawall and a few enhancements will provide adequate protection and save the ratepayers $millions.

    The HBRC motor is now running better but one more vote is needed to fix the steering. At least one Napier representatives on HBRC should offer support – please hang in there. Find attached Submission #125 opposing the Dam on long term effects to HB’s gravel coast. Any comment welcome.

    Link to Full Submission #125:
    http://www.hbrc.govt.nz/HBRC-Documents/HBRC%20Document%20Library/RWSS%20subs%20120-159.pdf

    Submission: Proposal to Invest in the Ruataniwha Dam
    Submitter: Larry Dallimore
    Postal address: P O Box 12 085, Ahuriri, Napier 4144
    Property address: 4 Charles Street, Westshore, Napier 4110
    HBRC Hearing: I wish to present my submission in person.

    My position: I support water storage schemes but oppose any project that has an ongoing detrimental effect on the environment. The proposed dam will make a significant contribution to the degradation of gravel beaches from Clive to Tangoio.

    1. The dam will block the Makaroro River which transports sediment from 42% of the total erodible catchment area for the Tukituki River. (see expert evidence page 4)

    2. During severe seasonal storm events, the natural movement of this significant resource of gravel should not be impeded. Any interruption to the supply of gravel and manipulation of the flood flows will accelerate coastal erosion. The entire beach from Clive to Bluff Hill was in a state of constant accretion until around the 1990’s. (see photos page 5&6) The absence of major river flooding since and over extraction in the Tukituki, Ngaruroro and Tutaekuri rivers may account for this.

    3. Annual gravel supplies to the coast since 1993 have been minimal and substantially less than 30,400 m3 annual losses by abrasion (see page 7) without considering the 70,000 to 85,000 m3 removed by machinery. (see page 27) Annual extraction from the Tukituki River system (based on royalty returns?) since 1993 has averaged 187,030 m3. (see page 8) Therefore, during the last 20 years of near zero coastal input, extraction controlled by HBRC has deprived the coast of 5,000,000 m3 when the bulk is vital for maintaining beaches in accretion, or at least in equilibrium.

    4. The last two major flood events in 1988 and 1992 supplied the HB coast with 477,000 m3 of gravel over three years up to 1993. (see page 9) The absence of such events over the last 20 years has contributed to growing deficits of sand and gravel within beach systems which would account for continuing erosion on the coast.

    5. Environmental Effects Report – May 2013 notes “sedimentation in the Reservoir at 260,000 m3 per year is a conservative estimate”. (see page 12) However, HBRC data sediment transport rate at the dam is 55,600 m3 per year 1980-2009, (see page 16) with a 40% “maybe missing” adjustment to 77,850 m3 per year, (see page 16) then HBRC 2012 changes the rate to 134,230m3 per year. (see page 19)

    6. The average 260,000 m3 of sediment, currently passing the proposed dam site each year, will be blocked and fill the reservoir when the dam is built. However, HBRC calculate 127,328 m3 of sediment will transport beyond the dam. In this case, HBRC detail is inaccurate because the life of the dam would be doubled. (page 19)

    7. The HBRC accepts the proposed dam will reduce gravel input to the coast by 1,688 m3. This calculation includes an exceptional period of over extraction and includes the extraordinary period without significant floods. This minimises the effect of the dam. Most recent major events occurred in 1975, 1988 & 1992. (see page 19)

    8. The dam will reduce flood flows necessary to transport sand and stone to the coast. Sedimentation Assessment Report – May 2013 quote: “mean annual flood flows will reduce by 47%”. (see page 20)

    9. Water flow volumes in the Makaroro River represent 14.5% of average volumes at Red Bridge, near the river mouth. During the cyclone season (most likely major flood events) reduced flow volumes will exponentially reduce sediment movement downstream. Degrading flood flows between Dec and Apr (also peak period for irrigation), will substantially reduce movement of gravel to the coast. (see page 21)

    10. HB’s gravel beaches are totally dependent on natural uninterrupted supplies of sediment. Gravel from the Tukituki River is the sole source of replenishment for beaches between Clive and Tangoio. (see #10 page 23)

    11. Professor Paul Komar, commissioned by the HBRC, validates my concerns with a clear warning in his report “the extraction of gravel from the Tukituki River is having negative consequences to HB’s gravel beaches which is causing shoreline erosion and the inundation of low lying backshore properties”. (see #11 page 23)

    12. HBRC should address over extraction of gravel in the rivers and on the beach plus the constant trapping of sand in a regularly deepened shipping channel at the Port. The dam is another man-made impediment to the natural movement of gravel.

    13. Statement of Proposal – p13 understates disadvantages under 4.2.1 Environmental Impacts. Quote “the mitigation programme is very comprehensive” is an over statement in relation to the effects on the coastal environment. (see page 25)

    14. Statement of Proposal p13 quote: “the comprehensive nature of the mitigation programme should ensure very little, if any, adverse environmental impact occurs as a result of the RWSS”. (see page 25) This statement will prove to be misleading.

    15. My Submission No.136 was submitted to the EPA in July 2013 and presented to the Board of Inquiry in December 2013. It was rejected because the BOI, for unknown reasons, determined any interference to gravel from the Makaroro River was insignificant to the amount of gravel reaching the coast. (see pages 26-28)

    16. HBRC Chief Engineer, Mr Ayde was asked to consider the sustainability of extracting up to 18,000m3 of gravel from Pacific Beach when Prof Komar determined no more than 6,000m3 is replaced by the natural coastal sediment drift each year. Disregarding the obvious degradation at the Marine Parade beach, the engineer found there were no problems or need for investigation. (see page 31)

    17. My submission was presented to the Hearing without the prior benefit of engineers refuting my assessment or expert engineering consultants producing rebuttal evidence. The HBRC brief was “issues beyond the river mouth are not to be considered”. (page 33) HBRC Senior Engineer, Mr Glode did respond by email on 23 January 2014 but was of little use, 35 days after the Hearing. (see page 34)

    18. The HBRC intends to place 1,700 m3 north of the river mouth where erosion will impact and 1,700 m3 south where it will have no benefit because this placement will move rapidly in the northerly drift towards Clive during the next SE swell. This is a meagre quantity to compensate gravel blocked by the dam, even with HBRC doubling their amount of 1,688, deemed necessary to mitigate loss. (#15 page 35)
    19. The excavation of 3,400 m3 within the same river system then trucked to the river mouth in close proximity would simply speed up deposits to the coast with no net benefit to mitigate erosion. The next moderate flood would make this expensive “Peter pay Paul” operation a pointless exercise. (see page 35)

    20. Information and comment provided by the HBRC following the EPA Hearing required further explanation and clarification. My courteous request for further detail dated 7 April 2014, is attached. (see pages 37-39)

    21. HB’s gravel beaches need a series of major storms similar to Cyclone Allison (1975) and Cyclone Bola (1988). Providing gravel is not impeded by man-made structures or extracted by machinery, the resultant flood flows of river gravel to the coast will restore damaged beaches and any pre-existing erosion will be reversed.

    22. My submission on the LTP in 2012 was to be my last. HBRC staff refused to explain the Councils resolution – “Beach nourishment is the best long term solution for Westshore”. After agreeing to pay full costs and the Ombudsman directing HBRC to respond, the outcome of my submission remains “an unexplained statement”. The solution controlled by the HBRC since 1987 has been a dismal failure. The same unsatisfactory outcome is expected for this presentation however, the purpose of this second submission is to place my concerns on record so future generations can reference genuine efforts made on their behalf. (pages 40-41)

    I seek the following:

    1. The HBRC should not proceed with any project that reduces or limits floodwater flows in the Tukituki River which alter the movement of sediment to the coast. The dam will exacerbate pre-existing erosion at beaches between Clive and Tangoio.

    2. The HBRC should cease all shingle extraction on the Marine Parade Beach after Paul Komar confirmed my assessment, presented to NCC in 2010 and HBRC in 2012, that the practice is unsustainable. (see page 30-31) The HBRC who has full control of the project, should immediately terminate the permit and be accountable for any further degradation along the Marine Parade coastline.

    3. The HBRC should take responsibility for activity at the Napier Port where 20,000m3 of sand is trapped in the shipping channel each year. (see page 42) According to coastal experts, this sand would otherwise transport in the coastal sediment drift and replenish Westshore Beach. The huge inshore deficit and damage to the barrier ridge, due to inadequate and incompatible nourishment, should be addressed with urgency. Waiting several years for HBRC, HDC and NCC to consider a Coastal Strategy will be an unacceptable delay and high risk option. (page 43)

    Conclusion:

    The Proposal to Invest in the RWSS has been promoted without consideration for the long term negative effects on the HB coastline. As a stakeholder in HBRIC which controls the huge reserve of excess revenues, I believe the investment risks are unacceptable and the inevitable harm to the environment will be a tragedy.

    Signed:
    L W Dallimore

  2. Tom, the proposals you describe may well be a better way to go than the present HBRIC’s scheme. However, I believe that ANY scheme should be financed by private investors only, although I might concede that central government subsidy might be in order. Further, any scheme must improve the environment, especially with respect to the Tuki Tuki river’s water quality. In practice I suspect any dam will degrade the river’s quality. It seems that here in New Zealand there is a constant push to force the land to produce more than it is naturally capable of doing, given the type of soil and the local climate. Surely we have damaged the biodiversity of this country far too much!

  3. I think this is a viable alternative and deserves further Council investigation. I am concerned about the build up of shingle behind the wall as has happened in many dams overseas. Is there a creative engineering solution to this problem?

  4. In response to Angela – this is my understanding and feel free to correct me. Viability of this Dam depends on how far one considers consequential effects and harm to the environment. The catchment for the Makaroro River is relatively soft greywacke stone which produces high volumes of stone and sand compared to hard rock canyons. Shingle is expected to build up behind the Ruataniwha Dam to the point when water storage volumes are inadequate to supply demand. This is when the water course will be re-opened and the project is abandoned. That day signals the economic life of the Dam which is (need to check) about 100 years. Costs to mechanically excavate and transport shingle from the inside face of the Dam back into the Tukituki River system are prohibitive.

  5. I am not an engineer, I am not a farmer, I do not have vested interests in this dam scheme. I am just a ratepayer.

    I have taken interest in this proposal because I was born in Waipawa and know the Central Hawke’s Bay region, having lived here for 70 yrs. I believe this scheme to increase productivity in this area — eg larger dairy farms, more stock, more cropping etc — will only benefit the existing producers who just seem to want more money.

    The proposal, which will reduce the flow of gravel to the eroding coastline and put more nutrients via runoff into the present water system, is detrimental to the long term interests of the area. I am also against my rates being used when there are more important things to spend them on.

    On a lighter note, watch “Fred Dagg” in a skit which I believe has relevance to this topic.
    http://baybuzz.wpengine.com/archives/7596/

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