Waimea Community Dam
(Lee Valley) - Tasman
Irrigation New Zealand Conference – Napier 7 – 10 April, 2014
Murray King
Joseph Thomas
Waimea Water Augmentation Committee
Lower Waimea River Drought (dry
river)& Flood (1500 m3)
Background
• The Waimea Plains is acutely water short - water rationing
7 out of the last 10 years.
• Shortfall 22 – 70% (~600 – 1900 l/s) depending on what the
low flow requirements in the Waimea River are set at.
• Committee (WWAC) brief
“To find a solution to acute water shortage on the Waimea
Plains”
• Limited high value land
• Diverse land use
• Long irrigation history
• Well understood water resource
• A multifunction dam proposed
Reservoir
location
The Proposed Scheme
• Concrete faced rockfill dam (CFRD)
• Size of reservoir
13.4 million m3
• Lake size
65.9 ha
• Dam height
52 m
• Construction time
~2 years
• Est. cost @ 2009 (excl hydro) ~ $42 million*
*Cost likely higher when CCI and final design/peer work completed – also subject to final tender price
• Time to fill
1 -3 months
• Irrigable area
5850 ha(eq.)
• Tasman(now/future)
1400 ha (eq)
• Future Regional
515 ha (eq)
Dam Centreline
Scheme Ownership Structure
• Scheme would be owned by water users
(community-owned co-operative scheme)
• Operated on a cost recovery basis
• Proportion of cost should be borne by
community as a whole to cover the
environmental flows (incremental cost of
building a larger scheme) – 30%
• Other costs shared between users on basis of
water demand
Where are we
• Regional Plan progressed since late 2012
Dam & No dam Option provided & Hearing
completed late 2013
• Commissioners decision notified in early March
2014 – important benchmark re no dam
restrictions – significant water cuts kick in
15/16 if no dam - cuts up to 50 % every year
and more beyond this - EDA findings next slide
• Consent preparation underway – 95 %
complete, prelodgement/lodgement of
consent ~ April 2014
EDA - GDP Findings – Cost of No
Augmentation
$1.77b
Increased
production and
processing
$66.5m
per
year
$1.19b
over 25
Hydro generation
bonus
$5.6m
per
year
$140m
over 25
Cost of NonAugmentation
$17.5m
per
year
$440m
over 25
This equates to GDP of $800,000 per hectare over 25 years
Design
• Detailed design 85 % complete
• Hold until consent notified and any relevant
submission evaluated
• Complete detailed design and tender
• Using rating mechanism require SCP and LTP
planned 2014/2015
Challenges
• Both Regional Plan and Consents – Statutory
processes
• Consents – agreement on mitigation
• Land acquisition
• Timing SCP/LTP – Political
• Funding vs. financing – sources/options/CII
• Efficient tender and costing
Discussion Q & A
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34.Joseph Thomas Murray King