Hurunui Water Project

Client:  Hurunui Water Project
Date:  2009 – 2017

The Hurunui Water Project (HWP) is a proposed large scale irrigation and hydropower generation scheme located in the Hurunui District, North Canterbury. PDP has been engaged by HWP to undertake an assessment of environmental effects associated with the resource consent applications for the scheme and to assist with feasibility studies for the project.

The originally consented scheme involves the abstraction of water from the Hurunui River, a number of large scale dams in the Waitohi River along with Storage on the (Amuri) Plains. In total, consents were obtained for the scheme to irrigate approximately 58,500 ha.

A major component of PDP’s completed and ongoing work for HWP includes hydrological analyses and irrigation supply and demand modelling.  The irrigation supply and demand modelling was critical for determining the irrigation requirements for the area, to size the storage reservoirs and assess effects on the Hurunui River.  The hydrological investigations for this project have included:

  • Determining an appropriate minimum flow release for the most downstream proposed dam in the Waitohi River to ensure a continuous flow in the downstream reaches of the Waitohi River.
  • Analyses of the effects of the proposal on the Hurunui and Waitohi River for the natural, existing and proposed state. Outputs included flow statistics, hydrographs and flow duration curves as well as flushing flow frequencies for both the Hurunui and Waitohi River.
  • Developing mitigation measures such that the effects of the proposal on flows in both the Hurunui and Waitohi rivers were mitigated. These measures included appropriate minimum flow releases and flushing flow releases from the proposed dams in the Waitohi and take cessation for the proposed abstraction from the Hurunui River to allow freshes to flow untapped to clear the river of periphyton when required.

PDP completed hydrogeomorphic assessments including an assessment of the impacts of the storage dams on the Waitohi River.  This assessment included estimating the potential sediment loading in the dam and providing estimates of downstream armouring and channel bed degradation.

To understand the effects of more intensive farming activities and irrigation as a result of the scheme, PDP completed an assessment of nutrient load limits for the Hurunui River and surrounding tributaries as well as an assessment of the effect of the proposal on groundwater.

PDP have been working with HWP since 2009 and continue to provide services for the project.

 

Key Aspects:

  • Rainfall and catchment hydrology modelling
  • Irrigation supply and demand modelling
  • Sediment transport analyses
  • Nutrient assessments
  • Groundwater analyses
  • Resource consenting and hearing evidence

Client:  Hurunui Water Project
Date:  2009 – 2017

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