Submission re Mokau Dam

Duncan Catanach compiled the NZRCA's submission opposing King Country Energy's proposed dam on the Mokau River.

To: Waitomo District Council
From: New Zealand Recreational Canoeing Association
Date: 15 April 2005
Re: King Country Energy – Resource Consent Application for Mokau Hydroelectric Power Scheme

  1. Submitter Contact Details

    Name of Party: New Zealand Recreational Canoeing Association (NZRCA)
    Contact Name: Duncan Catanach, North Island Conservation Officer
    Contact Phone: ###-###-####
    Email Address:
    Postal Address: PO Box 284, Wellington, New Zealand

  2. Applicant Details

    Name of applicant: King Country Energy

    Application numbers: 112394 – 112412

    Details of Applications: Construction, operation and maintenance of a hydroelectric power scheme on the Mokau River (commonly known as the Mokau Hydroelectric Power Scheme – MHEPS).

  3. Our Submission

    The New Zealand Recreational Canoeing Association makes the following submission in opposition to the application.

    1. Details on Submitter

      The NZRCA is the national representative organisation of canoe clubs and recreational kayakers throughout New Zealand. The NZRCA is an incorporated society and is affiliated to the NZ Canoe Federation, which is in turn affiliated to the International Canoe Federation. The NZRCA has delegated authority to represent the NZ Canoe Federation on conservation/access issues.

    2. Reasons for making submission

      Our primary reasons for opposing the proposed hydroelectric scheme are:

      • The Mokau River is recognised as being of high significance to kayakers and canoeists and has a long history (over half a century) of significant usage by kayakers and canoeists.
      • The proposed scheme will permanently inundate some of the most highly valued whitewater available in the Taranaki / Waitomo / Waikato regions and the North Island more generally. Moreover, it will severely reduce the recreational and amenity value of the Mokau River below the proposed dam and may also affect whitewater useage on the Mangaotaki River, a tributary of the Mokau River.
      • The applicant did not consult adequately prior to the resource consent being publicly notified. In particular, a lack of timely and wide consultation resulted in the draft Assessment of Environmental Effects report containing factual errors which may have unfairly prejudiced the resource consent process.

      Further details are given below:

      1. The Mokau River is recognised as being of high significance to kayakers and canoeists
        • The AEE report for the proposed Mokau hydroelectric power scheme (MHEPS) recognises that the Mokau is an important Taranaki kayaking river.
        • The run from Waitere dam to Totoro Gorge bridge is detailed on p. 84-5 of the leading whitewater guidebook, New Zealand Whitewater: 125 Great Whitewater Runs, by Graham Charles. The Mangaotaki River run which also uses the lower Mokau River is also described in Graham Charles' guidebook (p. 83).
        • In Egarr's 1989 guidebook, New Zealand's North Island Rivers: A Guide for Kayakers and Rafters, the Mokau (Totoro Gorge) River run is listed as one of the top ten whitewater trips in the North Island. The Mokau River viewed by many as a nationally significant kayaking river.
        • The Egarr River survey carried out in 1981 classed the Mokau – Totoro Gorge section as having Picturesque scenic value and High recreational value. The same survey describes the Lower Mokau as having Impressive scenic value and High Recreational value.
      2. The Mokau has a long history of significant usage by kayakers and canoeists.
        • The Totoro Gorge run on the Mokau River (i.e., from Wairere dam to the Totoro road bridge) has been regularly paddled by a variety of paddlers since 1949 when the first documented descent of the Mokau was made including the naming of significant rapids, such as Little Huka. We would like to emphasise the long – over half a century – and continuing association of whitewater kayakers and rafters with the Mokau River.
        • The Mokau River is also highly recognised by kayakers for its scenic and environmental values. The reliable flows and challenging bedrock rapids on the upper section of the Toroto Gorge are popular with kayakers from throughout the North Island and in particular Auckland, Hamilton, Rotorua, Taranaki, Wanganui and Wellington regions. The change in river geography from greywacke bedrock formations to the scenic Totoro limestone gorge is much appreciated.
        • Easy kayaking trips are paddled on the lower Mokau including commercially guided trips. The dam and proposed fluctuating (low) flows are likely to impact negatively on these trips as well.
        • Ideal flows (above 125 mm on the gauge at Wairere Power station) occur 60% of the time according to flow data contained in the AEE. However the Mokau is regularly paddled at flows as low as 7- 8 cumecs (80 – 100 mm on the Wairere gauge), particularly during times of low rainfall. Note that the Mokau River flows at 8 cumecs or above approximately 75 - 80% of the time.
        • As Graham Charles' book notes (see p. 80), the majority of Taranaki's whitewater rivers originate on the mountain. The implication of this is most rivers in the region can only be run in spate (i.e., when there has been significant rain on Mt. Taranaki) and due to the small catchments only for run at paddleable flows for a short time. The Mokau River, then, is especially important for kayakers when there has been no recent rain in the region because the river generally has reliable flows and makes a good paddle even at low water levels. During Summer and Autumn, the Mokau is often the only reliable intermediate grade (Grade 3 or above) river available in the Taranaki region. Consequently, paddling occurs during all seasons, not just Winter and Autumn.
        • The AEE suggests that access is a problem for the Totoro Gorge run. In fact, access is not a problem – almost all kayakers use the Totoro bridge takeout (as described in Graham Charles' guidebook) as they prefer to enjoy the full beauty of the limestone gorge as well as the whitewater in the upper section. It is hardly surprising then that local landowners have not had many requests for access.
        • In summary, the AEE is erroneous in stating that kayaking usage is low. The Mokau run detailed in Graham Charles' guidebook is regularly paddled in all seasons, and by paddlers with a wide range of abilities, as difficult rapids can be walked around if the paddler's ability is not sufficiently high.
      3. The proposed scheme will permanently inundate the bulk of the more challenging whitewater on the Totoro Gorge run and will significantly reduce the overall recreational value of the river
        • The current get-in for the normal Mokau run is the Wairere Falls station. The proposed hydro scheme will drown all of the highly valued bedrock formations which contain the challenging Little Huka and Dragon Tooth rapids, as well as several kilometres of grade III water with 1-2 metre drops, chutes and playwaves
        • The AEE does not adequately recognise the high value and unique qualities of the rapids contained within the bedrock formation zone above the proposed dam site. In fact, the bulk of the more challenging whitewater on the run is in the section of river that will be inundated. There are significantly fewer rapids on the river below the dam, and only two major rapids, one just above and one below the Mangaotaki confluence. Inundation of the upper rapids, although it is only 4.5km of the total 14km run, will thus significantly reduce the overall whitewater value of the river, potentially to the point that the river will be seldom run.
      4. The proposed scheme will also have significant adverse effects on the recreational amenity value of the Mokau River below the proposed dam
        • At flows above approximately 28 cumecs the MHEPS hydro management will be essentially be run of river. As the Mokau is regularly paddled at flows as low as 8 cumecs, there will be a significant loss of whitewater amenity within the region, over and above the loss of the upper section drowned by the proposed dam. In fact, flows between 8 cumecs and 28 cumecs make up approximately a very high proportion of the river's current flow rates.
        • Additionally, 28 cumecs relates to a gauge reading of approximately 185 on the Wairere gauge. In Graham Charles guidebook, he notes that at flows above 215 on the gauge the Mokau becomes Grade IV (compared to GII – IV at flows below 215) – 185 on the gauge is approaching this higher level. If run of river hydro management only occurs at flows above 28 cumecs, the river will be at a higher grade, significantly limiting the river's appeal to intermediate kayakers, who make up a high proportion of the current users of the river.
        • In summary, the proposed minimum flow of 2 cumecs is likely to be too low for kayaking the section of whitewater below the proposed dam site. It will curtail paddling at low to medium flows when there are few other options for paddlers in the region and will generally limit the river to infrequent high-water runs by more advanced paddlers (who have the ability and wish to paddle the river at higher flows).
      5. The whitewater run on lower Mangaotaki River, a tributary of the Mokau River, will also become difficult to complete because of the low water levels in the Mokau River below the proposed dam.
        • The proposed hydro management scheme will also affect the lower Mangaotaki River run (Grade III – IV - see p. 83 of Graham Charles' guidebook) which runs from the Mangaotaki picnic area on the State highway and finishes on the Mokau at the Totoro Gorge bridge.
        • This run is unlikely to be possible under the proposed scheme as the Mokau will have very little water in it until flows are over 28 cumecs. We would reiterate that this will only occur approximately 15% of the time, a significant reduction in paddling opportunity from the current flow regime.
      6. Consultation by the applicant was neither timely nor sufficiently wide.

        The AEE recognises that the Mokau River is an important Taranaki kayaking river. Initially, the AEE contained several significant errors of fact, particularly with respect to flow regimes (it mistook 125 mm – 10 cumecs - on the gauge to be a flow of 125 cumecs and thus suggested that suitable flows only occur a small percentage of the time). Contact with the NZRCA was only made on 15 February 2005, despite the recreational report of November 2004 suggesting consultation with the NZRCA and local clubs. While the applicant has corrected the most significant errors of fact in its revised AEE, we would suggest that consultation was not as timely or wide as it should have been and this may have unfairly prejudiced the resource consent process.

    3. Amendments to application sought

      The proposed scheme will permanently inundate a significant proportion of the whitewater value of the Mokau River, and severely reduce the recreational amenity value of the Mokau River below the proposed dam and the Mangaotaki River. Consequently, the NZRCA seeks that the application be declined in its entirety rather than amended, unless the whitewater features, particularly those upstream of the proposed dam are preserved in their natural state.

    4. Decision sought

      The NZRCA seeks that the application be declined in its entirety.

    5. Standards or conditions sought

      The NZRCA is opposing the proposed scheme in its entirety and seeks that the whitewater features, particularly those upstream of the proposed dam are preserved in their natural state.

  4. Attendance at pre-hearings and hearings

The NZRCA is interested in attending a pre-hearing meeting

The NZRCA wishes to present their submission/speak about the applications at the hearing.


Duncan Catanach

North Island Conservation Officer

New Zealand Recreational Canoeing Association