CIF Project - Taranaki Irrigation Study

Taranaki Irrigation Study Final Project Report

Taranaki Irrigation Study

Grant No: 10/04

Last updated: April 2012

Contact details

Name of Applicant Group: Taranaki Regional Council
Contact person: Gray Severinsen, Policy Manager
Address: Private Bag 713, Stratford 4352
Telephone: 06 765 7127
Email: Gray.Severinsen@trc.govt.nz

Project details

Status: Finished
CIF funding: $60,000 excl GST
Proposed start date: 1 July 2010
Proposed finish date: 30 June 2011
Region: Taranaki
Related website links:www.trc.govt.nz

Project description

The project is to identify and evaluate potential options for water storage and rural irrigation schemes to service those areas of the region that are of higher irrigation potential. Storage locations could be either on the flat intensively farmed ring plain or in the adjacent hill country or marine terraces. Storage options could be either on-farm or of a larger scale serving a wider area.

The project is to include a preliminary assessment of the geotechnical and engineering feasibility of a number of selected sites and the overall economic viability of different options considering development costs, operating costs, production gains and economic returns.

The project will consider the potential to integrate with existing schemes and infrastructure and explore opportunities for multi-purpose infrastructure.

The issue/opportunity

Taranaki is facing increasing water abstraction pressures. Heavy reliance on run-of-the-river flows in the face of rising pressures reduces security of supply, lowers median flows and results in lost economic potential.

The high density of rivers and streams in Taranaki, ease of accessibility to water and the perceived lack of suitable locations for and/or high cost of land and of developing water storage infrastructure have all presented barriers to better and more efficient use being made of the region’s water resources through water harvesting and storage.

The project is to address these issues and explore opportunities to make better and more efficient use of water taking into account economic benefits and costs and protecting social, cultural and environmental values.

The context/background

Taranaki is generally well endowed with fresh water resources receiving regular rainfall and having many mountain-fed streams flowing through areas of high demand, particularly on the ring plain where intensive dairying predominates. However there are significant and increasing pressures on freshwater resources. Taranaki is one of New Zealand’s leading dairying regions and this results in significant abstraction pressure being placed on rivers and streams for stock, farm dairy, pasture irrigation and other on-farm uses.

Taranaki can experience water shortages and serious droughts in drier summer months leading to the need to restrict water abstraction and use with the attendant disruption for water users and lost economic opportunities. These water supply problems are compounded by the generally small size of rivers and heavy reliance on run-of-river flows.

Increasing abstraction pressures also leads to increasing and more persistent impacts on stream hydrology and ecology. Greater investment in water harvesting and storage at times when water is available has the potential to reduce these impacts and provide opportunities to boost economic activity and production in the region.

Methods

The project will essentially be a desktop study to test the broad feasibility of water storage and irrigation options. The project will comprise the following steps:

  • Gathering existing information
  • Reviewing the current situation, identifying issues, constraints and opportunities, and gathering key technical data
  • Identifying potential locations for water storage considering areas of higher irrigation potential and other water needs, suitable areas and areas to avoid and defining preferred locations for further analysis
  • Undertaking desktop engineering and economic evaluations of rural water storage and irrigation scheme options considering the cost of land, storage capacity requirements, costs of land development, infrastructure capital costs, operating costs, production gains and economic returns
  • Identifying other considerations that any promoters of water infrastructure projects will need to consider.

Project Update:  February 2012

Work to identify where it is likely to be economically viable to develop irrigation has been completed and the results have been presented to TRC. As identified in the project proposal, the methodology used in the 2003 study by Bob Rout was used. The same zoning methodology was adopted and there were some improvements of soil categorisation to enhance the representation of the variability.

Feedback from TRC indicated that they were receiving interest in irrigation development in areas identified in the study as not being economically viable for irrigation. Because of this more detailed analysis was carried out to capture the irrigation water demands and increase resolution, particularly around Hawera and Opunake. Notwithstanding that this study was aimed at conducting a high-level regional scale study, it was decided to increase the resolution of both climate and soil classification to better represent the study area. 

Analysis of river flows and adequacy for supplying run-of-river and/or storage was carried out.

Concept scheme designs and cost estimates were completed for the highest irrigation demand areas. Examples of costs of other schemes were sought so that comparisons of costs could be made.

Assessments were made of how irrigation schemes may be able to incorporate rural water supply schemes. The project report provides comment on this issue.

A draft report was provided to TRC on 19 January 2012 for their review and comment. Following useful feedback the report is now complete.


Project Update: October 2011

Work to identify where it is likely to be economically viable to develop irrigation has been completed and the results have been presented to TRC. As identified in the project proposal the methodology used in the 2003 study by Bob Rout was used. The same zoning methodology was adopted and there were some improvements of soil categorisation to enhance the representation of the variability.

Feedback from TRC indicated that they were receiving interest in irrigation development in areas identified in the study as not being economically viable for irrigation. Because of this further, more detailed analysis has been carried out to capture the irrigation water demands and increase resolution particularly around Hawera and Opunake. Notwithstanding that this study is aimed at conducting a high-level regional scale study, it was decided to increase the resolution of both climate and soil classification to better represent the study area. This work is now complete.

Analysis of river flows and adequacy for supplying run-of-river and/or storage has been carried out.

Concept scheme designs and cost estimates are complete for the highest irrigation demand areas. Examples of costs of other schemes have been sought so that comparisons of costs can be made.

The final report is in draft form and is currently undergoing internal review.


Project Update: June 2011

Work to identify where it is likely to be economically viable to develop irrigation has been completed and the results have been presented to TRC. As identified in the project proposal the methodology used in the 2003 study by Bob Rout was used. The same zoning methodology was adopted and there were some improvements of soil categorisation to enhance the representation of the variability.

Feedback from TRC indicated that they were receiving interest in irrigation development in areas identified in the study as not being economically viable for irrigation. Because of this further, more detailed analysis has been carried out to capture the irrigation water demands and increase resolution particularly around Hawera and Opunake. Notwithstanding that this study is aimed at conducting a high-level regional scale study, it was decided to increase the resolution of both climate and soil classification to better represent the study area. This work is now complete.

Analysis of river flows and adequacy for supplying run-of-river and/or storage has been carried out.

Concept scheme designs and cost estimates are complete for the highest irrigation demand areas


Update: February 2011

Work to identify where it is likely to be economically viable to develop irrigation has been completed and the results have been presented to TRC. As identified in the project proposal the methodology used in the 2003 study by Bob Rout was used. The same zoning methodology was adopted and there were some improvements of soil categorisation to enhance the representation of the variability.

More detailed analysis has been carried out to capture the irrigation water demands and increase resolution particularly around Hawera and Opunake. Notwithstanding that this study is aimed at conducting a high-level regional scale study, it has been necessary to increase the resolution of both climate and soil classification to better represent the study area. This work is now complete.

Analysis of river flows and adequacy for supplying run-of-river and/or storage has been carried out. Some further analysis of river data is continuing.

Concept scheme designs and cost estimates are progressing.


Update: October 2010

Information gathering and reviewing of trends and data is complete.

The review of the work carried out in 2003 by Lincoln Environmental (Optimisation of Farm Irrigation) is 95% complete. A slightly more detailed and therefore robust approach has been taken to ensure appropriate identification of the key demand areas. This is a key stage in the study because it is this work that identifies the areas where it may be economically viable to invest in irrigation. This allows work from this stage to focus upon serving these key areas.

Some analysis of river flows has been carried out to determine their capacity to provide for storage and from here identification of suitable storage options has commenced.

 

Last Updated: 27 June 2012

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