Tekapo Whitewater Trust Report to NZCA/NZRCA AGM
The Tekapo White Water Trust was formed in March 1992 to manage the funds received by the NZCA from Electricorp pursuant to an agreement in relation to water rights made in 1990 between ECNZ and NZCA. The Trust is responsible for the planning, design and construction of facilities in the Tekapo river bed in order to upgrade that river to provide whitewater recreation for touring, downriver racing, and slalom by increasing the grade and diversity of white water features.
In the last five years progress has been slow but steady. We have seen three project managers come and go but I am very happy to report that the Trust has reached provisional agreement with a major contractor for the construction of the course.
After construction planning details are completed, we hope to start construction on site in October 1997 with the first flow tests likely to be in November/December 1997.
Attached to this report is this seasons flow dates of the Tekapo and Pukaki rivers as agreed between NZCA and ECNZ.
The Tekapo White Water Trust may wish to modify the release flows in the Tekapo river in November /December 1997 to test and commission the new dam, weir and slalom course. This may include flows exceeding 60 cumecs but such modifications will be subject to NZRCA and ECNZ approval and will be requested closer to the time. ECNZ may also approve additional flows for testing the new structures.
The Trust commissioned Proper Channels Ltd., England to provide a feasibilty study for different options in October 1993. They concluded that a world class artificial slalom course could be constructed on the Tekapo and be a major attraction to the region. They further concluded that a high quality course would be difficult to envisage within the bed of the existing horseshoe bend rapid and that the cheapest and most technically viable option was to excavate a new channel 680m long joining the two ends of the horseshoe. This would give an average gradient of 1:68 and with a flow of 60 cumecs, and has the potential of being the finest in the world.
In November 1993 the Trust considered six options for development as detailed by the project manager and chose option B2 which excavates a new channel along an old river channel as the perferred option.
The original option from Proper Channels was costed out to be far beyond our budget and would involve excavating 190,000 cubic metres of material. Option B2 involves excavation of only 18,000 cubic metres of material with an estimated length of 450 metres, and head of 7 metres giving an average gradient of 1:64.
In December 1993 Royds Garden Consulting Engineers were asked to quote for a feasibility study and design using option B2 and were asked to commence work in January 1994.
In late January 1994 a Royds pre-feasibility study estimated the total costs to be around $600,000 which was clearly well beyond our budget and they were asked to provide a much reduced option. After further work from Jens, Eric and Royds, a new estimate of $415,500 was reached in February 1994. This estimate allowed for a 650m long course with an average gradient of 1:76 and 8.5 metre head.
The Trust felt that this estimate was still above the desired result and Royds was asked to redesign for something that cost less. After much design and redesign, options were considered (especially for the weir and intake structures) and the final design was agreed in September 1996. This design was put out for tender but the best price was still $44,000 short of the funds available. By August 1997 the shortfall had significantly reduced to $10,000 which we hope soon to cover with further funding.
Basic course information:
- 450m Slalom Course
- Intake Structure and Play Wave
- Max 60 cumec course design flow
- Flip Gate Weir Structure
Finally I would like to welcome all paddlers to the Tekapo river and to be actively involved in making the Tekapo White Water Canoe Course the place to be.
Tekapo White Water Trust