Revised 11/08/2001

OVERVIEW EFFECTS OF THE CLUTHA HYDRO SCHEMES ON THE ENVIRONMENT

  1. Clutha River Dams In General.
  2. The Very First Effects - Fish And Eels.
  3. Alexandra Sewage.
  4. Clutha Mouth Flooding.
  5. Why The 1990ís Floods Had Such An Effect On Alexandra

  6. Why the Difference.
  7. After the November 1999 Alexandra Flood.
  8. The Destruction Of Alexandra.
  9. Cromwell Sediment Concerns.
  10. Lake Hawea Guardian Operating Concerns.
    Contact Energyís Water Renewal Right Consent Length.
  11. Daily River Fluctuations
  12. Sediment.
  13. Who Is Responsible For The Sediment Problem - Legal Remedies

(1) THE CLUTHA RIVER DAMS IN GENERAL

The Power Company - Contact Energy

The present Clutha hydro schemes are now owned by Contact Energy Ltd and comprises of the Lake Hawea Control structure and the two power generating facilities, one at Clyde and the second at Roxburgh. Contact Energy as well as generating plants in the North Island. The main shareholder and now holding approximately over 50% of Contact Energy shares (financed by Mission Contact Fiancé), is US- based Edison Mission, a subsidiary of Edison Californian.

The Dams

Most of the major effects to the Clutha River, in the past and the present arise from the Roxburgh dam and from Lake Roxburgh. The main effect is considered to be associated with sediment of lake filling and down river. Lake Roxburgh was formed in 1956. Shortly after in 1958, the Lake Hawea control structure was completed so as to store and control the water supply, first for Lake Roxburgh and from 1992, Lake Dunstan. Now even in this very short time, Lake Dunstan has quickly shown it to has an effect not only on the Clutha River, but also on its tributary, the Kawarau River.

(2) THE VERY FIRST EFFECTS - FISH AND EELS

Dam blockage

The first notable effect was the immediate block of Roxburgh dam created a massive hindrance to the passage of fish and eels traveling down stream and completely preventing them back pass the dam to their spawning grounds. The Hawea dam structure also acts as a block, but to fish only, as eels are more than likely can by-pass the relatively small structure. Nothing has been down at the Roxburgh dam in the 45 years it has been running. Now the Clyde dam construction provides a third block to fish and eel passage. Contact Energy does not want to address this problem also, yet itís their dams that have blocked the upriver passage migration of fish (brown trout mainly and salmon) and eels, and when traveling downstream, the dam turbines cut up both the fish and eels. Nearly 100% of all the eels are cut up on the way through the turbines. Back in the 1960ís, Roxburgh locals would observe 100ís of dead cut up eels on the Clutha below the dam.

The early Europeans introduced the trout - brown and rainbow, and the salmon from the northern hemisphere while the long-finned eel is a native and only found in New Zealand and has a very interesting life cycle.

The long-finned eel prefers streams, rivers and lakes quite a distance inland. For decades they remain inland before beginning one of the most intriguing animal migrations, traveling on a 5000-km journey to the tropic Pacific to spawn and die. The 5000-km return journey as larva takes some 15 months traveling back to the New Zealand coast transforming into a "glass" eel before making there way upland up rivers now as elvers, migrating back to their penultimate destination. The long-finned eel is now threatened specie in the Clutha catchment. Their numbers were decimated in the Otago lakes in the 1970ís by commercial fishing. Today there are few of these eels left above the dams.

Though the eel is one of the longest-living animals, reaching an old age of 60-70 years, if nothing is done soon and because of these dam blockages, the long-finned eels of the Clutha River lake system will became extinct.

Fish Passes & Screens

The solution is simple - fish passes and screens at all three dam structures. It is done overseas with some success in America (the California Harvey dam 1999, the New England Connecticut river power dams 1977), Canada and the UK. In Scotland it has laws. The Salmon (Fish Passes and Screens) (Scotland) Regulations 1994, where now all dam structure most have a fish pass and screens put in place.

See "How Daily Water Fluctuation Flows Has Effects on Fishing"

(3) ALEXANDRA SEWAGE

Sewage Pollution

Another noticeable first effect was that of the Alexandra sewage. In 1957, the crude sewage was collecting in the still water created by the new Lake Roxburgh. The health authorities posted notices all over the foreshores, prohibiting swimming because the water was polluted. Previously the sewage had been rapidly disintegrating in the once fast-flowing Clutha water.

Accepting The Responsibility In The 1950ís

The Alexandra Borough Council considered the State hydro-department was morally responsible for providing the borough with a satisfactory solution to the problem. Another government department, Ministry of Works, which supervised the construction of the Roxburgh dam for the State Hydro-Electric Department, stated that there were grounds that it created the conditions that caused the problem.

The Minister of the State hydro-department agreed that his Department would make all the necessary alterations to the Alexandra Boroughís sewage problem by installing pumps, and primary station at its expense.

Ref: "A Place In the Sun - A History of the Alexandra Borough Council" page 148 &149.

Back in 1957, the Minister omitted that the Alexandra sewage pollution problem was as a result of the creation of the Lake by the Crown and provided a satisfactory solution to the residents of Alexandra.

Not Accepting The Responsibility In The 1990ís

How different in the early 1990ís when the Minister was approached and informed that the build up of the sediment was as a result of the Lake been constructed by the former Crowns own departments. (In 1988 these departments became State Owned Enterprises before being privatised in the mid / late 1990ís.) This time the Crown did not accept they had a moral responsibility, or of taking ownership of the problem, and as well ignored the issue.

Further it was very convenient in 1999 for the Crown to sell off the Clutha hydro dam schemes. Then in 2000, the Crown still not accepting that they are responsible for the problem of lake sediment built up but they did admit that the sediment built up had raised the level of the 1990ís flooding at Alexandra, came up with a cheap and "temporally" solution - floodbanks. This was done in conjunction with Contact Energy, but it has left Alexandra with more problems and of passing the future cost of the floodbanks onto the citizens of Alexandra.

MORE ABOUT SEDIMENT LATER

(4) CLUTHA MOUTH FLOODING.

The Clutha River is New Zealandís largest river by volume, dropping 277 metres at Lake Wanaka to the sea in 322 kilometres. The three lakes - Lake Hawea, Lake Wanaka, and Lake Wakatipu supply the Clutha River on average, with more than 84% of its water. (Lake Hawea 13%, Lake Wanaka 39%, Lake Wakatipu 32%.)

On average, the river mean flow is of around 490 cumsecs. However in the flood season - late spring to mid summer, the river flood average flow is normally of some 2,000 cumsecs compared with the biggest recorded flow of that of "The Big 1878 Flood" which peaked flowing past Alexandra at 4,650 cumsecs (Otago Regional Council). The river, pre-dam period, would normally carry the sediment, on average of just over 1.5 million cubic metres out to sea, providing transportation and deposition along the east coast towards Dunedin. Majority of this sediment comes from the Shotover catchment via the Kawarau River joining the Clutha at the Cromwell Junction.

Roxburgh Dam

In 1956 this changed as Lake Roxburgh was built smack in the middle of the rivers length such that the gravels and most of the silt were now trapped in behind the dam. The Clutha River was tamed and the coast was now deprived of its major source of silt that was once replacing the sand been continuous removed as a result of wave erosion from the beaches along the coast.

However there was some compensation as due to the decrease in sediment colour, the water was now cleaner, but the dam created a new problem. Now, as the Clutha River was leaving from the Roxburgh dam with extra energy, it was scouring soils out of the riverbanks wherever they were not rock-defended. Variations in the river daily discharge from power production, stripped banks of vegetation, leaving then with no opportunity for healing. In pockets the erosion is severe and the changes in the lower riverís alignment which have resulted and still causing endless problems. The dam discharge ranges between a very low flow to 820 cumsecs such that the level of the Clutha may fluctuate by more than two metres daily at Millers Flat, 26 kilometres down stream from the dam.

MORE ABOUT DAILY RIVER FLUCTUATIONS LATER

Local Flooding At The Clutha Mouth

The lower Clutha delta is formed by two branches - the Matau (north branch) and Koau (south branch) with the land between known as Inch Clutha, meaning in Gaelic "Clutha Island". Any major floods inundated the delta.

When the river flow is insufficient, and is made worse when the weather comes in from the south, the sand gravel bars are silting at the mouth, such that the water is unable to escape when the river flow is returned to normal. The result then that there is local flooding of the farmland in the vicinity of from Kaitangita to the mouth. The silt can only be flushed away when the river is running high or when bulldozers are used to break a channel through the bar.

Floodbanks

During the flood of 1958, flood storage within the Roxburgh dam reservoir was used to retard the peak flow passing downstream. Subsequently lake siltation has reduced the available storage capacity by some 44% and the dam today is not used to regulate flood flow for the Clutha mouth.

Work on the Lower Clutha Flood Control Scheme started in 1961and completed in 1972. The State hydro-department reluctantly accepted that they were partially responsible for the cause of the local flooding and made a contribution to the capital costs. Floodbanks were erected and pumps installed but the department was not willing to accept the ongoing maintenance costs.

Today many of the farmers consider the floodbanks in floods are causing additional problems. The flood plan has been lost when the Clutha is in a natural flood. Further, the flood plan can only be reached / used if the flood bank is breached. The flood damage is worse with a sudden influx of water compared with a gradual rise in the flood level.

Todayís Problems

These concerns arise from the silting up of the riverbeds of both branches, from Balclutha to the coast. This silt has gradually been lifting the riverbed and will soon be level with the surrounding land. Today upriver from Balclutha, as far as Clydevale, islands in the river that once could be reached by boat, some can now be reached by foot. Further a large amount of silt that comes with the volumes of flushed sediment from behind Lake Roxburgh is not making it out to sea.

Better management of river control will ensure the silt does all get out to sea.

 

(5) WHY THE 1990ís FLOODS HAD SUCH AN EFFECT ON ALEXANDRA

Flood History

"The Otago Regional Council now officially have the "The Big Flood of 1878" - the 500 year Flood", flowing past Alexandra at 4650 cumsecs, reaching a height of 140.52m asl at the Alexandra Bridge and just creeping up Tarbert street. Shaky Bridge across the Manuherikia River was build 1879 and the flood level would have been about a metre below the deck if it had been built before the flood. The last bid flood pre Roxburgh dam era, was the 1948 flood of 2450 cumsecs.

Three floods hit Alexandra in the 1990ís - January 1994, December 1995 and November 1999. The flood of 1994 was of 2330 cumsecs - 140m above sea level (asl), close to the size of 1978 of 2570 cumsecs, the so called "100 Year Flood" but was still one and half metres higher flooding Rivers Road below Tarbert Street. The 1995 flood at 141.91m asl, higher than the 1878 flood with a flow of 3550 cumsecs and waves of the flooded Manuherikia River washed over the Shaky Bridge deck. The Manuherikia River experienced the biggest recorded flood of some 600 cumsecs.

The 1999 flood was even bigger at 3800 cumsecs peaking at 142.3m asl and became the second biggest flood recorded on the Clutha though this flood was higher by some 1.8 m of the biggest recorded flood but only 80% of the volume! The water peaked at Limerick St and the Alexandra Bridge was closed except for emergency traffic. The Clutha River backed up the Manuherikia River and gently lapped over the deck of Shaky Bridge. (The Manuherikia River was not in flood.) These flood flows are Otago Regional Council figures - March 2000 Document, which Contact Energy consider that most of these are too high.

WHY THE DIFFERENCE.

THE ALEXANDRA FLOODS ARE DIFFERENT. The ever-increasing sediment build-up in Lake Roxburgh is as a direct result of the man made dam construction at Coal Creek, Roxburgh creating Lake Roxburgh. This had increased considerably the flood levels at Alexandra, which by then in 1994 had reached a maximum of well over three metres (ORC Report). Consequently areas of Alexandra, now suffer flooding from smaller floods, that werenít flooded in the biggest recorded flood of 1878. This was well recognized by ECNZ / Contact Energy for some time and by Otago Regional Council, but these concerns were not forward officially onto Central Otago District Council till after the 1994 flood. (ECNZ memo)

Shotover River

The massive built up of silt originates from the Shotover catchment which joins the Kawarau River a short distance below the outlet of Lake Wakatipu. The silt was first being deposited in Lake Roxburgh when formed in 1956 till 1992. After 1992, the silt is now being deposited in the newly formed Lake Cromwell in the Kawarau Inlet.

Lake Roxburgh

Consequently, Lake Roxburgh has now not only lost more than 44% of its storage capacity, as well the lakebed has been raised considerably.

The Two Roxburgh Gorge Restrictions

At the top of the lake, the higher lake level was nearly three metres at the time of the 1995 flood, from the Alexandra Bridge down some 5.5 kilometers to the Narrows. Once through here, the river widens as it flows through Island Basin and on down towards the dam. The Narrows, before the lake was filled, was originally a location of a dangerous rapid and then known by the early miners working in the gorge and then later on the river dredges, as the "Golden Falls".

As well, 675 metres down from the Manuherikia junction, the river narrows to a width of 39 metres between two schist bluffs, which is locally known as the Italian Bend. The Roxburgh dam designers were well aware from one of their own reports. This restriction has a significantly adverse effect back at Alexandra. (Public Works / MOW report dated about 19480) "At high flows, the restriction has the effect of ponding water, causing a backwater curve at the gauge at the bridge".

Now with both restrictions and along with the raised riverbed as a result of sediment built up of more than three metres, has caused the higher levels of the three 1990 floods at Alexandra.

Manuherikia River

The lower section of the Manuherikia River now gets hit when both or either the Manuherikia River / Clutha River is in flood. Built up of sediment is now of over 7 metres from below Shaky Bridge at the mouth. The sediment build up is felt some 7 kilometers up river to the old site of the second Galloway Bridge and floods most of State Highway 85 by up to 2metres in places. In effect the mouth is choked. Both Contact Energy and the Otago Regional Council have no intentions to remove the gravel build up of the riverbed. However is a minor consideration, the ORC will carry out river channel control above the first Galloway bridge.

Flushing

Contact Energyís solution after the 1995 flood was to use "flushing" to move the silt down the lake. They now claim that as a result of their no cost "flushing program" commencing in 1995 and put in place when the river is running high, that the level of flooding at Alexandra has now been reduced by about a metre. All that the flushing has done is the redistribution of the silt further down the lake. Some of the sediment goes into suspension and travels on downstream which if goes on too long has adverse effects on the environment - fish and invertebrates. Resent surveys is showing that the as time goes on the effectiveness of the flushing is reducing proportionately to what it can shift each time the program is implemented.

ECNZís / Contact Energy Comments

In April 1994, as a result of a joint study report, ECNZ was found that they were responsible for the flooding at Alexandra. The sediment build-up was the major cause of the January 1994 flooding. Further before, during and after the building of the Roxburgh dam, former Government departments had advised all the various government ministers of the Crown, back as far as the 1940ís that there will be a massive building up of silt, once a dam was built at any location site along the Kawarau River and on down to the Clutha River to the sea.

Downstream effects from flushing

Though most of the sediment is redistributed in the lake, suspended sediment is washed either via the turbines over the dam. The river fluctuations result in the sediment not reaching the ocean but any prolonged flushing effects the fish and the river bottom feeding invertebrates. The fish gills get lacerated and their stomachs fill with fine sand. After some 5-7 days, the fish die. White bait numbers has also suffered with a major reduction in numbers.

Government Departments

These former government departments - Public Works and NZEC no longer exits. Public Works was later to become the Ministry of Works (MOW), a State Owned Enterprise (SOE) in 1988 and in 1996 majority of its departments sold off with Works Consultancy renamed to OPUS International Consultants - international owned by a large Malaysian company. NZEC also in 1987 become a SOE, renamed to ECNZ, and then later itself split up in 1995 into two competing SOEís, one being Contact Energy. In 1999 it to was sold and now controlled by international ownership Edison Mission Energy owning Roxburgh dam, Clyde dams and as well other power schemes in New Zealand.

Responsibility Goes With Ownership

The Crown and those former Government departments responsible in the of building of Roxburgh Dam and now Contact Energy Ltd who today owns the Roxburgh dam, all ignored these early reports and by not taking any remedy action, shows gross negligent on part of the Crown, its agents and Contact Energy Ltd. (ECNZ / Contact Energy memoís) There has been no serious physical work or expenditure in undertaking in any form of action to control and to remove the silt, knowingly it was being deposited and raising the lakebed which would in time of a flood, result in raising the flood level at Alexandra. There have been other environment issues not that have not acknowledged.

Negliance

With negliance comes liability, which ultimately is the Crowns responsibility to solve the problem. To date they have not done so. Further there has been little good will to the people of Alexandra. The only recognition has been token compensation to some property owners along the Manuherikia River years after the 1978 flood - some were not honoured, and now in 2001 with some recent compensation to the town, more payouts to more properties along the lower Manuherikia River, and commercial and residence properties along the Clutha that were affected by the 1999 flooding. Most of these buildings have now been demolished either to make way for construction of two small floodbanks funded by Contact Energy or to remove the embracement of flooded buildings. Another lot of commercial buildings in the down town area will more than likely go in the name of "progress".

Contact Energyís Floodbanks

Contact Energy though having financed the flood banks, have no intentions of taking ownership of them once built. Once again they have not accepting the responsibility of their actions they have done. The ongoing maintenance costs are to be born by the ratepayers, more than likely by the Alexandra residents. Many of the Alexandra residents see this gesture by Contact Energy as a cheap form of a public relation exercise so they are then seen to be doing something towards mitigate the problem just to make them look good in front of the Commissioners at the Water Renewal Right hearing.

The Two Floodbanks

The purpose of the banks is to try to prevent future flooding to the business area of the town and to shut the back door at an area know as Linger and Die. Many of the residents of the town do not see them to be an effective solution. The town is largely built on high gravel river terrace with at least one underground river system that runs under part of the town ending where it joins the Manuherikia River at Linger and Die - right where one of these floodbanks is now being built.

Yes, they will have pumps installed to control rain run-off and seepage, but any rise in the river level has a direct rise in the water table as anyone can see at any of the old dredge ponds in the tailings along both sides of the Clutha River. As well, these are electric powered pumps and the possibility of loosing power would cause further problems. Large storms and big floods often close down power generation schemes and cut power lines. Both Clyde and Roxburgh dams are under designed to cope with floods of anything considered to be bigger than 1 in 100 year floods. The Big 1878 Flood was for a long time under estimated as being of 3,300 cumsecs - a 1 in 500 year flood event. Back up power schemes are being put in place but they can also fail.

The problem is the result of manmade interference to the nature Clutha River flow. That is where the problem needs to be remedy - not on the land, which will inferably lead to more problems.

Full Commensuration And A Permanent Solution

The Crown and ECNZ / Contact Energy are all legally required to pay out full compensation payments to all those in Alexandra that have suffered in some form from the three floods of the 1990ís, and to come up with a permanent solution of the sediment problem. Why. The Crown, ECNZ and now Contact Energy have either been in the past or are the owners of the Roxburgh Dam power scheme problems. The condition of the three sales was for all assets and liabilities to be transferred, but what were the liabilities. All parties would have known that with any dams constructed, there would be the inevitable built up of silt coming from a river catchment systems, especially that coming from the Shotover River.

Both the ORC and CODC were convinced that there was no case against the SOEís after the 1994 and 1995 flood though Contact Energy after the 1994 flood did make a payout to flood damage to CODC infrastructures, on conditional that there would be no more comebacks from future floods. The agreement was signed without even been viewed by the Council lawyers. Not a very wise move. Soon afterwards, came the even bigger 1995 flood causing even more damage.

Civil Cases

No one was prepared to take Contact Energy to Court except three civil cases. One case lost as the to the interpretation of an easement over their land and now been challenged, the second case was successful and the third case is still in court. In 1998 the owners of the Alexandra Holiday Camp originally sued ECNZ mainly for damages, lost of earnings from the 1994 / 1995 flood. ECNZ handed the case over to Contact Energy Ltd. The case was finally settled out of court in June 2001 with the owners extremely satisfied. The settlement also included recovery of their legal fees. The third case is of ten Insurance Companies. They allege that the hydro-electric dam operators should have taken action to prevent flooding at Alexandra.

Go to Who Is Responsible for the Sediment Problems -Legal Remedies

Known Facts Since 1920

The Government and government departments have known for along time of the Shotover River sediment capacity. That was confirmed in the 1920 Rivers Commission Report on the Clutha River. Again all parties were made aware again as far back in the 1940ís when the Clutha River was being looked at for hydro-scheme development and in 1948 when the Government approved the construction of the Roxburgh dam.

Number Of Reports

Apart from these reports, and there is a lot of them, their is physical conformation of how the river level has risen in the last 120 years. By comparing the 1882 old Alexandra bridge piers from photos taken in the 1880ís, late 1950ís / early 1960ís and then now 2001, shows the comparable river levels. The 1880ís photo shows clearly the two arches below the bridge decking and the pier base foundation. A photo taken during the autumn of 1963, has the bottom arch with water at the half way level, both as a result of the river higher from the forming of the lake in 1956 and from more than 40 years of sedimentation collecting on the lake bed.

Present Observations

Today when looking at a present autumn photo, or just looking at the river when it is low, there shows above the water level, only the top section of the bottom arch. Bridge construction engineers would have taken note of the massive 1878 flood and would have taken that into consideration when designing the Alexandra Bridge. The road traffic decking would have been above the highest recorded volume of water flowing pass the Alexandra Bridge. However if the 1878 flooding had happened in 1999, it would have been flowing well over the bridge decking railing, if it were still there! The 1999 flood, though less than 80% of the 1878 flood, still was able to reach where the decking level once was.

Even more convincing evidence comes from looking at aerial photos. A photo taken in 1958 shows a clean river channel to the Alexandra Bridge and around the first bend into the upper reaches of Lake Roxburgh, no sand banks and with few willow trees growing along the river banks. Now from an aerial photo taken in 1997 or flying overhead today of the same area, shows no longer a clean river channel, but one of sand banks and sand bars - in particular the build up in the Manuherikia river and the large sand bar on the inner bend opposite the Manuherikia River, and the massive increase of the willows that are growing along these silt trapped banks that have now established themselves long most sections of the river.

 

(6) AFTER THE NOVEMBER 1999 ALEXANDRA FLOOD

Predications became a Reality

The flooding predications became a reality as the town once again suffered unnecessary from extensive damage to property and business firms from man made conditions knowing caused by neglect from those that controlled the Clutha hydro- schemes. Even at the time of the flooding, questions again were been asked, why and who was responsible and then what can be done to stop the unnatural flooding of Alexandra.

Public Outcry - Alex Adams Report

At an outcome from a public meeting, the CODC were to ask the Crown for a solution to the Alexandra flooding problem. The Crown commissioned Alex Adams in November 1999, to be the Clutha Solutions Coordinator, not to only look at the Alexandra problem but to all the flooding along the Clutha. His final report released June 2000 for the Ministry for Emergency Environment - "The Project Seeking Practicable Solutions For Clutha River System Flooding" did little to solve the Alexandraís problem though did came up for a degree of compensation to those flooded in Alexandra and construction of temporary floodbanks at Alexandra.

The Optimx Report

In parallel to the Alex Adams report, the Alexandra Community Board through the CODC commissioned Optimx Ltd for a Strategy Proposal - Future directions for Alexandra Strategy Study with three objectives:

  1. The strategy should address community needs
  2. The strategy should address individual needs
  3. The Strategy should be conciliatory, fair, and pragmatic in terms of the current and anticipated future need of the residents of Alexandra.

The strategy failed in objective 1 and only partially achieved 3. Though there was consultation, much of the final report was not meet with the approval of the majority of the Alexandra and the Manuherikia communities. The compensation was accepted but not the floodbanks as the sediment build up was again ignored. However the community leaders accepted the Optimx Report June 2000, as they did with the Alex Adams Report.

Deed Of Understanding - Montgomery & Watson Report

And yet there was still a third report unbeknown to the Alexandra people. The Crown / Contact Energy recommended the Montgomery & Watson Report, commissioned by the Otago Regional Council to come up with an engineering design and costings of the floodbanks. The end result was a M$21.58 package as outlined in a Deed of Understandings - some M$15 from the Crown to provide for property compensation and a Community Grant fund, and Contact Energy to provide up to a maximum of M$6.8 for the building of flood banks.

The Crown and Contact Energy would consider this payment as a "gift" to the Alexandra community but by law it could be the very least that they could have done. Both have put the people of Alexandra through the last three floods causing unnecessary damage, cost of repairs, ruined chattels, hardship, discomfort, trauma, inconvenience, anxiety, loss of profits, diminution in value of land and buildings, lost opportunities, loss of goodwill and interest can be claimed from the date on which the losses were suffered.

Two of the key tasks werenít resolved - facilitating processes to identify practical options for mitigating the risks and to examine the specific issue of siltation of the hydro lakes and the repeated flooding at Alexandra. I leave it over to you to come to your own conclusions.

 

(7) THE DESTRUCTION OF ALEXANDRA.

The Oversight Committee

The Crown / Contact Energy package deal went ahead. The Crown, represented by the Oversight committee, had the Crowns land agency - LINZ (Land Information New Zealand) to buy up all flood prone properties and place easements over land that will again flood. LINZ subcontracted the purchasing negotiations work out to Property Group.

Property Purchase

Initial progress was slow. Their main priority was the purchase of land for the building of two floodbanks - a small flood bank at the Linger & Die, Manuherikia River and a slightly larger flood bank along the Clutha River for protection of the Central Business Development and along the Left Side River Bank above the Alexandra Bridge. Both these flood banks are designed to give protection to a peak flood level of R.L.143.75 m as measured at the Alexandra Bridge.

Other properties along the Manuherikia River and along the right bank were either purchased or agree for an easement to allow flooding. Most of these purchased properties have been or will soon to be demolished.

The Linger & Die Bank

This flood bank required the demolition of four houses. Three of these houses had been one owner. One built 1946, the second 1951 and the third built in 1992. The third one was the one that suffered the most from all three floods - the 1994, 1995 and 1999. Gone were their dream homes. The fourth was rented. The tenant was believed to have been paid $6,000 and to take what he liked to move out with only a few days notice, so the house would be demolished along with the other three.

Included in the Linger & Die purchases are two more houses, two apartments, the Council swimming pool complex, Scout hall, Alexandra Museum and Senior Citizens Rooms. The small Linger & Die community has now gone for good all because the real problem was not been addressed.

The Central Business District (CBD) / Left River Bank

Even more destructive was the destroying of the old lower down town section of the town which contained what some would describe as heritage buildings surrounded by more recent business buildings and one house.

The immediate destruction required a house (Walkerís), Molyneux Motors (a well established garage), the Bendigo Hotel built about 1901/02 (likely received the greatest payout of some M$1.4), Active Print, CRT building, the towns optometrist, a building that hadnít been leased much in the last years but received a generous payout, another two houses, two flats and Two Bob Packers up river also demolished as well as compensation to two developers for a land submission project of some 20 sections.

Retail Development

Within the lower downtown to make way for a large retail building complex - likely for The Warehouse Ltd goes Reid Farmers, the former BNZ 1885 building which is register in the Central Otago District Plan as a Heritage building, Video Alexandra, Alexandra First National Real Estate, Smith City sports, Bruce Robertson Travel, ENZA NZ Alexandra Office, AMP / Landcare building, spare section, The Inn and Hendersonís Cycles. Most of these buildings will be purchased out if the Community Amenity money amounting to some M$1.3. Also effected is the lose of The Pie Cart site

The proposed retail building complex of approximately a gross area of 4,000 square metres, breaches many of the rules of the Proposed Central Otago District Council Plan and as well the former BNZ building is in the Register of Heritage Buildings. The Warehouse Ltd in partnership with the CODC is now asking for a Resource Consent for changes in the District Plan and as well as dispensation from a number of town planning rules. One in particular is that of not providing sufficient car parking, which will later cause some major traffic problems. The retail complex is too big for such a small site.

 

(8) CROMWELL SEDIMENT CONCERNS

Lake Dunstan / Kawarau Arm

In 1992 Lake Dunstan filling commenced. The sediment now above the Clyde Dam, was been trapped in Lake Dunstan, with the majority being deposited in the Kawarau Arm. Coming down the Kawarau River, as a cause of the problem, is the sediment from the Shotover catchment. Almost immediately, Bannockburn orchardists / vineyard operators who had irrigation pumps down in the Kawarau River, had to be raised to the fast filling up of sediment in the upper Kawarau Arm. Areas of the Kawarau above Bannockburn bridge that were once 30 metres deep now have became shallows, (ORC video release July 2001) sand bars have formed, a deterioration in fishing and boat navigation a problem.

Deed Of Grant Of Easement

The Crown and SOE knowing that the sediment was going to be deposited adopted a passive solution of allowing the sediment to be built up by taking out easements with property owners along the Kawarau River. It is very likely they were misinformed on how quickly the build up of sediment was going to happen and the consequences in the following years. Though this Deed wasnít signed till December 1998 between the Crown and Contact Energy Ltd, the Deed became an asset to ECNZ / Contact Energy in the sale and purchase dated 30 November 1995. Cause 6 allows the grantee from time to time deposit sediment on or about the easement land, Lake Dunstan. The on or about could be interpreted as the river bed - Crown ownership, which is likely why Contact Energy is claiming that these measures were to mitigate against the adverse effects. The Otago Regional Council has seen no reason to challenge Contact Energyís to remove the sediment. The legality and way the Deed has been handled is questionable and morally wrong.

Kawarau Arm Sentence To A Quick Death

The rate of sediment filling up at an average of 1.32 million cubic metres per year predicates a 21 + or - 4 years before the Kawarau Arm fills with sediment to the old Cromwell Junction. Model predications would more than likely have it closer to the 17 years. The Kawarau Arm will became useless for river recreation, continue relocation of irrigation pump intakes, increased and continuous river bank erosion, once the flow becomes braided on an alluvial fan - a delta, the Kawarau river will be prone to shift sideways in floods and likely cause accelerated erosion back as far as Ripponvale, flooding of Old Cromwell town, flooding of areas never previously been flooded, flooding of the Bannockburn Bridge, Bannockburn inlet will first became a wetland and then dry up, increase risk of flooding the Roaring Meg power and possibly sometime in the future the sediment effect on the river flow may increase the risk of higher flooding back in Queenstown.

Lowburn Basin

One of the conditions of the Clutha Development (Clyde Dam) Empowering Act 1982 was to reshape the shallow lake margins around Lowburn, so that a 2.5 metre depth is generally obtained. In all of the three 1990 floods but especially in the November 1999 flood, sediment that was washed down the Lowburn Creek was trapped in the shallow lake and the Lowburn mouth is choked - much like the Manuherikia River. Its now August 2001 and nothing has been down.

Upper Lake Dunstan

No so much a problem here as that of what is happening at the Kawarau Arm. The majority of the sediment carried down the Clutha into the upper section of lake Dunstan, originates mainly from the Cardrona River that no way matches the mighty Shotover River. In summer the lower section of the Cardrona has been known to dry up.

Snow melt and flood water brings sediment down and is now being deposit at the top and spreading into the Bendigo Wetland Reserve. Presently the wetland is providing a haven for wildfowl, aquatic invertebrates and freshwater fish. Soon recreations waterways will be lost and in time the wetlands will disappear as the sediment build up will became solid land.

With ownership of hydro-schemes comes responsibility and looking after the environment. The design and maintenance of any works relating to the right shall be of a standard adequate to meet the conditions of the right. Maintenance not only applies to the dam structure but should also apply to the river itself.

The problem is once again of Contact Energyís making and they must find a way to deal with it, stop side steeping the issue, stop allowing the problem to increase rapidly to the point where it will be soon become a major environmental disaster in the Kawarau Arm, the lose of the Lowburn lake and in time the disappearance of the Bendigo wetlands.

 

(9) LAKE HAWEA GUARDIANS OPERATION CONCERNS

Lake levels.

Below 340 m there is a significant and adverse impact on the amenity values of the lake; extensive exposure of silt covered gravel beaches; increased risk of wind blown dust problems from exposed foreshore and delta area; adverse impact on tourism and recreational use of the lake. The proposal is for maximum and minimum levels to be 340 m - 346 m while Contact Energy Normal are operating presently 338 m - 346 m.

Irrigation - Summer buffer zone

Below 342.5 metres, irrigation becomes inefficient and costly to maintain. A 2.0 m buffer required between 344 - 346 m to minimise risk of further erosion on southern foreshore, which occurs during events of high rainfall in the Lake Hawea catchment while strong NW winds generating wave surges up to 2.0 m on high lake levels. A buffer zone is required from 1 November to 31 March each year, with a minimum level 342.5 m. to a maximum level 344.0 m.

National Electricity Shortage

Only the use of a 2.0 m zone 338 m - 340 m can be used in circumstances of extreme national electricity generation shortages. The proposed zone can only be triggered by Parliament. The present zone is 336 - 338 m.

Contact Energy to make a time-related financial contribution to the Hawea Community Association Inc in compensation for the adverse impact that this lower operating level will have on the Hawea community. The money is to be used for the further development of reserves in the Hawea area.

When the lake is at low levels in spring / November, the river channels at the deltas are very shallow at the Hunter River, Dingleburn, and Timaru Creek etc. At these times, it is very difficult for fish to get into the rivers for spawning.

Coffer Dam at Gladstone Gap - Emergency Overflow Outlet

The cofferdam - an emergency overflow outlet, is a part of the Contact Energyís facilities at Lake Hawea and must be included in the resource consent application, or removed at Contact Energyís expense. If it is to be retained, then a management regime for its use, and any consequences that may arise from its use, should be set in place as a part of the resource consent process.

If the coffer dam is to be retained, then Contact Energy should set aside the area between the coffer dam and the lake foreshore for community use as a passive recreation / picnic area. Contact Energy should also provide public vehicle through their land to provide vehicle access to the cofferdam area.

If the cofferdam is to be removed, then Contact Energy should vest the land in the area to the Queenstown Lakes District Council as a recreation reserve, together with the Contact Energy owned land between LG303 and the lake foreshore.

Control Gate And Ancillary Structures At The Main Lake Hawea Dam Site.

These structures and the surrounding land should be painted, enhanced and landscaped to improve the visual appearance of this area which is on the main entrance into the Lake Hawea township and is also alongside State Highway 6, a major tourism gateway into the Central Otago / Southern Lakes region.

Erosion

Erosion has been occurring and is ongoing at the following locations:

Lake Hawea:

Hawea River:

The report commissioned from Land and Water Studies (International) Ltd (Prof. R Kirk & Dr M Single) should provide the Hawea Guardians with information about the historical extent of erosion along the southern and eastern foreshore and provide recommendations for minimisation / mitigation of these erosion effects.

Continued erosion of headlands alongside the Lake Hawea township, (especially Skinner Crescent) would undermine the sewer line, which at that point runs just a few metres from the cliff top. A breach in this line would result in serious pollution of the beaches front and water source for the Lake Hawea water supply.

Vegetation.

The present lakeshore is an unnatural shoreline created when the lake was raised in 1958. It continues to be unstable and dynamic. The southern foreshore alongside the Lake Hawea town ship has been substantially degraded since the lake was raised with battening-down of cliff headlands and other earthworks carried out to try to control erosion. Some early planting and landscaping was carried out by NZED / ECNZ, but this work has not been continued in recent years.

As a result, this southern foreshore land is now infested with wilding undesirable trees and noxious weeds. This will require considerable work and capital expenditure to bring up to a standard acceptable for the community.

A full management plan for the southern foreshore reserve needs to be set in place by the QLDC (following full community consultation) so that remaining areas of indigenous vegetation can be preserved and enhanced, areas of noxious weeds and undesirable wilding and exotic trees can be removed, a planned process of landscaping, and new planting of appropriate trees and vegetation can be commenced.

To facilitate this, the process at present underway for the Crown to acquire the strip of Esplanade Reserve land along the southern foreshore; to consolidate this with the existing southern foreshore land owned by the Crown; and then to vest the whole area in the QLDC as a recreation reserve, needs to be completed.

Lake Hawea Water Quality

The increased frequency of raising and lowering the lake level over recent years is leaving layers of silt sedimentation exposed on the shoreline. In NW wind conditions currents take this sediment to the lake outlet, where the intake for the Lake Hawea township water supply is also located. This has been resulting in greater turbidity in the town water supply, resulting now in the need for periodic, and much detested, chlorination.

This could be avoided by having a reduced frequency of fluctuating lake levels over the summer months when NW winds are more prevalent.

Hawea River

The normal maximum and minimum controlled outflows are at present 6 cumecs minimum - 200 cumecs maximum. Subject still to further discussions with Fish & Game, the proposal is 14 cumsecs minimum to 200 cumecs maximum. The present minimum flow should be no lower than the average minimum flow back before 1958, i.e. pre-Hawea structure. The Lake Hawea mean flow pre-dam, was measured at 63 cumecs. (MOW report March 1977.)

Go to NIWA Modeling Programme

The higher minimum flow will provide improved habitat for invertebrates and fish in pools in the river, will result in improved recreational and tourism amenity values - fishing, kayaking, rafting, camping etc.

At maximum flow, if river exceeds 200 cumecs, then excessive erosion results along the riverbank, in particular at Horseshoe Bend area and high river flows, especially at time when Clutha River catchment is in flood, increases the flood risk for Albert Town.

Tourism Issues.

State Highway 6 runs alongside Lake Hawea and is one of the major tourist routes into the Central Otago / Southern Lakes region.

The Lake Hawea town ship is a significant tourist destination, an important area for local and tourism recreational use, particularly during the spring, summer and autumn months. The main attractions are fishing, boating, water skiing, sailing, canoeing, walking / tramping.

Contact Energy should contribute towards the funding of some of these facilities and infrastructure facilities around the shore of Lake Hawea and the Hawea River, in recognition of the special difficulties that arise in these areas as a result of their use of the lake and river for power generation purposes.

Health Issues.

Historically, dust has been a significant problem for the community at times of low lake levels. In the 1970ís when the lake was lowered to 327 metres, dust clouds were experienced through Thompsonís Track, south of Tarras. Dust was such a problem at Johnís Creek that high wooden fences needed to be erected to try to keep it out of the township.

Dust clouds start to become evident when the lake level falls below 342 m during the summer months, when the prevailing NW wind picks up exposed silt from exposed delta areas at Timaru Creek, Hunter River, Craig Burn etc.

Below 340 m, this dust problem becomes an increasing problem for the community, raising concerns as to health risk for residents / visitors with breathing difficulties.

Turbidity.

The increased frequency of raising and lowering the lake level over recent years is leaving layers of silt sedimentation exposed on the shoreline. In NW wind conditions currents take this sediment to the lake outlet, where the intake for the Lake Hawea township water supply is also located. This has been resulting in greater turbidity in the town water supply, resulting now in the need for periodic, and much detested, chlorination. This could be avoided by having a reduced frequency of fluctuating lake levels over the summer months when NW winds are more prevalent.

Consent Length

Contact Energy is seeking resource consents for 35 years, the maximum period permitted under the RMA. Hawea guardians consider this to be too long and propose the consent for a maximum of 15 years followed by four 5 year review periods granted once there has been seen that there is an increase in performance from Contact Energy.

The Alexandra District Flood Action Society consider the 15 years is too long and should be only be for a maximum of 5 years tagged with a $100 million bond, followed by 5 year reviews. No improvements to the Environment, the $100 million bond is lost, Contact Energy Water Rights are revoked and Contact Energy are then required to reapply for Water Rights Renewal.

Mining applications are required to post bond money to the consenting authority. Mining is extracting wealth from the soil while electricity is been extracted from the lifeblood of water.

Under these present operating rules for hydro-scheme generation, it allows the destroying of the river ecology and for dumping of industrial waste in the form of sediment in the rivers, reservoirs / lakes.

 

(10) DAILY RIVER FLUCTUATIONS

Ramping at the Hawea Dam Structure

Water is released most days from Lake Hawea into Lake Dunstan to replace water used for power generation. This stop and go results in daily river fluctuations which can be as little as 6 cumecs, to as much as 200 cumecs which has a major effect on the Hawea River ecology and fishing in this stretch of river. The invertebrate numbers drop considerable as when the river stops flowing, the invertebrates are either left stranded or die from the higher water temperatures. The river invertebrates breeding cycle is broken. They recognise the flood season but with these daily fluctuations upset them greatly, resulting in species either becoming extinct and or population numbers drop.

As the fish feed drops, consequently the fish population drops accordingly. Before the dam structure, was built, sections of the river would comfortably support five fishermen, today only one. Fish breeding is also badly affected. When they spawn when the river is high, the trout eggs often either left high and dry or else get cooked in the shallow warm pools.

Ramping Clyde Dam to Lake Roxburgh

Water is released daily down river to Roxburgh Dam. This stop and go results in daily river fluctuations.

Fishing in this section of the Clutha River does not hold great numbers of big fish, though there is a reasonable population of small trout. This section of the river is not known for spawning. Little is known of the invertebrate here as the deepness and width of the Clutha has hindered research in the past.

Ramping Roxburgh Dam to the Clutha Mouth

The Clutha River now leaving from the Roxburgh dam has extra energy scouring soils out of the riverbanks wherever they were not rock-defended. Variations in the river daily discharge from power production, stripped banks of vegetation, leaving then with no opportunity for healing. In pockets the erosion is severe and the changes in the lower riverís alignment which have resulted and still causing endless problems. The dam discharge ranges between a very low flow to 850 cumsecs such that the level of the Clutha may fluctuate by more than two metres daily at Millers Flat, 26 kilometres down stream from the dam.

Also when the water is released daily from Lake Roxburgh as a result of power generation, it causes a major effect on the Clutha river ecology and fishing in this stretch of river down to the mouth. The invertebrate numbers drop as when the river stops flowing, the invertebrates are either left stranded or die from the higher water temperatures. The river invertebrates breeding cycle is broken. They recognise the flood season but with these daily fluctuations upset them greatly, species became extinct and population numbers drop.

As the fish feed drops, consequently the fish population drops accordingly. Fish breeding is also badly affected where fish spawning takes places at selected spots. When they spawn when the river is high, the trout eggs often either left high and dry or else get cooked in the shallow warm pools. Another effect is that the flushing has caused in places of slow river flow, slime accumulating on the riverbed covering algaeís that the invertebrates feed on and as well limits spawning sites.

NIWA Modeling Programme

These daily river fluctuations and as well with changing land use, greater abstraction of water, has resulted in a habitat decline. Although the instantaneous rate of change may be small, the collective rate over time can be substantial.

We must have a better way not only to manage the Clutha River, but all waterways.

The relation between habitat loss and flow is used to determine the impact of flow reductions and to set minimum flows that maintain adequate flows to sustain fish and invertebrates.

Using the NIWA Freshwater Fish Database and a modeling tool called RHYHABSIM (River Hydraulics and Habitat Simulation), the computer programme determines what fish species are present in a river and is able to access what effects a change in river flow will have on habitat. The relationship between habitat loss and flow is used to determine the impact of flow reductions and to set minimum flows that maintain adequate habitat and invertebrates numbers.

The model is required to be used first on the Hawea River, then the Clutha River from Roxburgh Dam to the mouth and as well on the Manuherikia River.

Manuherikia River

Though the Manuherikia River is not affected by daily fluctuations, the sediment built up from Second Galloway Bridge to the mouth is as a result of the built up in Lake Roxburgh. The mouth is choked and is not maintaining adequate habitat conditions and reducing the number of invertebrates. The river is dying and both Contact Energy and the ORC are doing nothing about it.

 

(11) SEDIMENT

Sediment Source

Sediment is a natural material that comes from both erosion and the down cutting of rivers. The Clutha catchment geology is very young. Its present form is likely only 200,000 years old. Though some of the 80% water Clutha water originates from three lakes providing clean water, itís the Shotover River that enters below the lake outlets that provides a massive amount of sediment on average of 1.32 cubic metres of sediment into the Kawarau River. In the week of the November 1999 flood this sediment load was double the average load.

The Shotover

The Shotover River itself has a relatively huge mountain catchment in a high rainfall area. The river flows through two steep canyons - the Upper Shotover Canyon and the Lower Shotover Canyon. The steep canyon walls are prone to land movement and scared with landslides. Over the years the Shotover, in itís cutting down process, has left behind river terraces.

Shotover Gold Mining

In 1862 alluvial gold was discovered in the Shotover River. Over the years the Shotover River became known as the richest river in the world. Very quickly it became apparent that the river terraces contained large amounts of alluvial gold. Water was bought to these terraces so as to allow hydraulic sluicing to blast away the terrace face. A huge amount of sludge and gravel was washed down into the river. Even today a large number of these terraces are still bare of cover making them an idea source to be washed away by the heavy rain adding to natural erosion material. Gold mining dredging in the late 1890ís and 1900s has also contributed to the sediment source. Toes of hill slides were dredged away causing an increase of landslides. In the Upper Canyon an operation to divert the Shotover from a large loop of the river by making a cut through the hill which became known as the Sandhills Cut.

However these man made attacks on the landscape and their consequent result of providing more sediment into the river however is small and of a short term nature, compared with the natural cause of events occurring in this very unstable landscape.

Skippers Bridge

The amount of gravel building up on the Shotover riverbed can be demonstrated at where the Skippers Bridge crosses the Shotover. When completed in 1900 the bridge was 92 metres (300 feet) above the river in normal flow. Today it is now only 72 metres to the river as a result of 20 metres of gravel fill from both upriver natural erosion and mining operations.

The Effect on Lake Dunstan

Go to CROMWELL SEDIMENT CONCERNS

The Effects On lake Roxburgh

Go to ALEXANDRA FLOODS ARE DIFFERENT

The Clyde Dam Tail Race River Dredging 1993

Its hard to see how this work was allowed to proceed as at the dam construction work was complete in 1990 and as well the Resource Management Act was in place in 1991.

However the deepening of this river channel below the Clyde Dam was a Condition allowed under the Clutha Development (Clyde Dam) Empowering Act 1982.

Dredge deepening was not to exceed 4 metres below the dam and the dredging to extent some 10 kilometres downriver tapering off to the level of the existing channel at the Alexandra Bridge. Deepening of the river bed would allow the dam to pass more water so is to increase the water flow pressure and consequently generate more electricity by as much as 2%. The work would only be viable to ECNZ if the contract would cost no more than $51 million.

The first contractor, Chas Pilcher, shortly after starting, went into receivership. The contract was then taken over by Fletcher / Ham. After some re-negotiations took place, a contact target cost of 50 million dollars was agreed upon. The Tail Race work costs were incorporated in the overall Cromwell Gorge Stabilisation Project Costs.

It took Fletcher/ Ham just over six months to cover the 10 kilometres stretch of the river and removed some 3.1 million cubic metres of gravel and blasted rock bed. The work was by the use of an excavator with a big bucket at the end of a long extended arm working from a badge. The material was dumped into barges and then moved by tugs and deposited at the old dredge tailings gravel quarry mid-way along on the Earnscleugh Flats. It was first spread out over the surface and then into the big gravel quarry hole that was nearly filled up. The quarry hole was made when the gravel was removed and used in the making of 1.2 million cubic metres of concrete that was used in the construction of the Clyde Dam.

The dredging work was completed December 1993. Costs broken down for convenience are Fletcher / Ham costs coming in under the $50 million at $49.0 million (Material removed at $12 / cm3).

Two Conditions of the Clutha Development (Clyde Dam) Empowering Act 1982 however were unlikely fulfilled.

The first Condition was for the spoil resulting from the channel deepening to be disposed of in such a manner as would not impede the river channel and floodway. It is estimated that an equivalent amount material made up of fine gravel (drift wash) ended down by, and just below the Alexandra Bridge as additional sediment deposits. Added to this was material that came from the Clyde dam construction. The in-charge personal flagged this to ECNZ Head Office. Not only HO were aware of it, they in the end did nothing to continue on with dredging even when all the equipment was still on location even after the January 1994 flood. In the months after, the equipment was tendered off so as to offset some of Fletcher/ Ham costs.

The second Condition was for the deepened channel to have its bed and banks armoured as necessary to prevent channel erosion.

During the November 1999 flood there was severe bank erosion just below the dam, as the banks here did not at all seemed to have been armoured. A large amount of material was washed away and likely ended up down just below the Alexandra Bridge. Early in 2001 this work was finally carried out in conjunction with repair work.

Read THE CLYDE SHAM - Surplus on a target contract and a missed opportunity for the people of Alexandra

Also another Condition was likely not met. There is a requirement to correct the river channel erosion in the Clyde / Alexandra reach of the river at the Alexandra Bridge The river channel has now changed from mid river running to now running alongside the left bank threatening both the bank and the old Alexandra bridge piers. The change is likely as a result of the 1993 dredging work.

The Effects at the Clutha Mouth

Go to CLUTHA MOUTH FLOODING

 

(12) Who Is Responsible For The Sediment Problem - Legal Remedies

The responsibility of the sediment problem lies with who ever owns the dam and the lake / riverbed. Ownership of either of these takes with them both a legal and moral responsibility.

Roxburgh Dam Construction

The crown in 1948, by order in Council under the Public Works Act 1928, conferred on itself the power to develop the Clutha River for the purposes of electricity generation. The Hawea and Roxburgh Dams were constructed under this authority.

After the Water and Soil Conservation Act 1967 came into force, the damming, taking and discharge of water for hydro purposes through the two structures was notified, in accordance with section 21(2A) of the 1967 Act, to the Otago Regional Water Board in March 1969. This gave the activities, 'notified use" status. The RMA 1991 states that all notified uses expire in October 2001.

Clyde Dam Construction

The National Government approved the Upper Clutha Power Development Scheme December 1976. The Clyde Dam project commenced in August 1977 after much controversy and with no water rights. This was finally rectified by the Clutha Development (Clyde Dam) Empowering Act 1982. This Act was to grant water rights along with a number of conditions to allow the Crown to operating the Clyde Dam on the Clutha River. It now seems that the water takes and discharges in this act were later repealed and replaced by operation consents issued by the Otago Regional Council under the Resource Management Act 1991.

Roxburgh, Clyde dams and the Hawea structure were built by former government departments and ran by former government departments. In many of the old ECNZ and Contact Energy files there are many references that they are were aware that they had caused the problem of the sediment build up and were legally liable as a result.

Electricity Act 1968 / Electricity Act 1992

A reference back on November 5 1987, the ECNZ solicitor BD Simpson, after discussion with group management, wrote that ECNZ accepted liability for the flooding in lake Roxburgh under Section 16 - Compensation for Damage, of the Electricity Act 1968 which was later replaced by The Electricity Act 1992 Section 16 became Section 57 - Compensation for damage and included a new Section 156 - Rules of natural justice to be observed.

Law Of Tort - Public Nuisance

"Use your property in such a fashion so as to not disturb your neighbors. Doing otherwise constitutes "nuisance " under tort law"

A private individual or individuals under nuisance action has a legal right to protect a personís use that could endanger live, safety, health, property or comfort of the public. The nuisance here is the flood waters that has came onto property and caused discomfit as a result of the non-natural use of the river allowing the plaintiffs able to claim for all losses caused by the unnatural higher flood levels.

Though the dams may haven been authorized by public works legislation, it does not authorize the flooding. Further there a high degree of negligence based on the failure to identify the sediment risk when the dam was built and then later when knowing of the sediment risk, ignored any action to reduce the risk. Only after the 1995 flood did Contact Energy try flushing to reduce the risk but this didnít stop the 1999 massive flood damage.

Common Law

Common Law is used to refer to the main body of English unwritten law that evolved from the 12th century onward.

New Zealand, as a colony, inherited the common law system from Britain and the English Law acts of 1854, 1858 and 1908 confirmed New Zealand as a common law country

Common Law operates through the doctrine of precedent and the development of legal principles through cases and judgments.

Resource Management Act (RMA) 1991

The over-riding principle of the RMA is sustainable management, defined as " the use, development and protection of natural and physical resources in a way or at a rate, which enables people and communities to provide for their social, economic and culture well-being and for their health and safety"

Section 17 Duty to avoid, remedy or mitigate adverse effects. This section imposes a general duty on every person to avoid, remedy, or mitigate adverse effects on the environment arising from an activity carried out on or behalf of that person. Significantly, the duty applies irrespectively of whether or not the activity is carried out in accordance with a rule in a plan, resource consent or (Section 10 and section 20), existing users and activities

Section 17(3) of the RMA may be the basis for the issuing of an enforcement order or abatement.

Section 5 (ss6, 7, 8) provides "Matters of natural importance" are subservient to the requirement to promote the substainable management of natural and physical resources

Section 4 is an Act to bind the Crown, allows for no enforcement order, or abatement notice can be issued against the Crown but does not protect State Owned Enterprises.

Section 15 provides for duties and restrictions of discharges of contaminants into environment which sediment can be viewed as an industrial contaminant causing damage to the environment and harmful to the communities.

All of these means Contact Energy has legal obligations to remedy damage from pervious flooding and to prevent future flooding. If Contact Energy is unable to meet these obligations it is clearly operating illegally.

Section 338 provides for the Offences against the Act and Section 339 the Penalties. Contact Energy and its precedents ECNZ, knowing they have been operating illegally since the Act commenced 1st October 1991 would, if the Otago Regional Council enforced the use of the Act, Contact Energy would be required to pay many millions of dollars in fines at the maximum of $10,000 a day - some $36 million!

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