The Hastings Water Supply relies on being able to abstract water from the Heretaunga Plains Aquifer from a number of borefields located throughout the supply area. Consents for these bores had previously specified annual volumes for each individual bore rather than providing for the management of the supply bores as an integrated system. The resource consents for these bores were due for renewal and GEM Consulting was engaged to assist the Council to secure a long term consent.
Consenting of infrastructure requires the optimal balance being obtained between certainty and flexibility. The network operator seeks sufficient flexibility to optimise, expand and develop the supply network during the term of the consent without being unreasonably fettered by consent conditions. On the other hand, the consent authority requires sufficient certainty that the resource is being used in a sustainable and efficient manner and that the environmental effects will be less than minor. GEM Consulting was able to satisfy the tension between certainty and flexibility which:
- Enabled the consent to be processed via limited notification and granted without need for a hearing;
- Obtained a consent with acceptable conditions which were essentially as proposed in the application; and
- Secured a long term (35 year) consent which provided for demand growth during the consent period.
What we did to meet the Council’s objectives:
Upon appointment, GEM Consulting analysed the current knowledge of the water supply network and developed a work programme which enabled Council to have certainty as to how they were going to develop, operate and manage their network within the term of consent sought (35 years). Time constraints required to achieve s124 RMA rights (ie to continue to exercise the existing consent while the renewal application was processed) meant that interlinked areas of work were required to be addressed in parallel, similar to the approach set out in our proposed methodology for the PNCC WSDP. GEM Consulting scoped, worked with consultants already engaged,
and facilitated the development of the following work packages:
- Groundwater assessment: This work package was about confirming the most reliable and sustainable groundwater source for providing current and future demands. We worked with Council officers to confirm their "ideal" scenario; where new bores should be located from a network management perspective; and likely future demand. We engaged with the Council's external groundwater specialist and worked collaboratively with experts, drillers and Regional Council officers to agree a methodology for undertaking pump tests and assessing stream depletion effects. This was an important step as it was not possible to implement standard test methodologies as this would have resulted in an unacceptable disruption to water supply services. Working with Regional Council officers meant that these methodology limitations were accepted and there was certainty that the methodology would not be questioned upon submittal of the application. The pump tests and analysis were then carried out with the agreed methodology;
- Water Use Assessment and Demand Management: The Council was already in the process of undertaking some trial pressure management zoning and assessing the level of unaccounted water. GEM Consulting undertook peer review of the existing work and then worked with the consultant to develop and programme further tests and methodologies to ensure that findings were fit for purpose, in accordance with international best practice and industry accepted methodologies, and that the work would be undertaken in a timely manner to be able to be used in the consenting project; and
- Network Optimisation: Council had decided to use Optimatics Ltd to undertake network optimisation. GEM Consulting worked with Council officers and Optimatics to identify system constraints, future demand nodes, level of service requirements and operating parameters which formed the basis of the optimisation model. This modelling work was undertaken at the same time as the groundwater and demand management work packages.
GEM Consulting also undertook the integration and facilitation role for this project and was responsible for preparing the Assessment of Environmental Effects and all supporting documentation. The above work packages were progressed in parallel, which required key decisions to be made on the basis of available information, and an iterative approach was required. For example, the groundwater assessment identified that two of the existing bores were having a more than minor stream depletion effect. The findings of this work were then incorporated in to the network optimisation model and new scenarios were identified and modelled.
The outcome of this process was that Council knew the level and timing of investment required to meet future demand and mitigate environmental effects. This meant that they were able to seek resource consent for the required resource for the duration of the consent (35 years) and that they were able to commit to mitigation measures knowing the corresponding price tag. It also meant that we were able to make a strong case in the consent application that existing bores that had a stream depleting effect should continue to be used (albeit in a different operational regime) in order to realise the remaining economic life of the asset, and to provide sufficient time for mitigation measures to be implemented at a pace that was affordable to the community.
Throughout the process, we engaged with Regional Council officers so that there was a common understanding of how water is used in a municipal water system, the particular operating constraints that municipal supplies operate under (eg, when compared to industrial or agricultural takes), and what is considered best practice within the industry. This meant that Council reporting officers were able to consider the efficiency and operation of the system against the relevant industry standards and benchmarks and ensured that conditions imposed were relevant and compliance would be able to be achieved.
The resource consent application was for an annual allocation volume from the Heretaunga Plains Aquifer, subject to instantaneous take limits at each bore (to manage local drawdown effects). This allows Council to optimise the operation of the system to meet demand, rather than being constrained by individual allocations for each bore.
The application also proposed a Water Conservation and Demand Management Strategy be developed which enabled the District Council to define what was meant by “efficient use” and the methodology by which efficient use would be assessed.
The resource consent was processed via a limited notification process with no submissions received. The long term water supply consent was granted without the need for a hearing and the conditions were as put forward in the application.
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