By Andrew Fenemor
Looking back, 100+ years ago exploitation of water resources focused firstly on rivers. Then water use especially for irrigation and urban supplies moved to groundwater takes. Now as pumping from our aquifers starts to deplete river flows and aquifer storage too much, we are seeing greater interest in water storage. Case in point, the Government’s Irrigation Acceleration Fund is supporting feasibility assessments for large schemes in Canterbury, Otago, Hawkes Bay, Wairarapa and Tasman, most involving new dams.
The trouble is, it’s a tough job for regional councils to set catchment limits in their regional plans (PDF) before the symptoms of excess appear. That’s not surprising, given the sizable investments in catchment science needed, the long time frames required to understand the inherent variability in water fluxes, water quality and aquatic ecosystems and the long time period required to establish new regional planning regimes. Setting catchment limits certainly focuses the mind. Most councils are now getting on with the job.
In a recent project for the Ministry for Primary Industries (MPI), we identified five high level outcomes being sought through water management:
- LIMITS: Values identified for protection are protected
- EQUITY: Fair, equitable sharing of access to water, and land uses that affect water
- EFFICIENCY: Maximise the benefits from use of the available water and land resources
- PARTICIPATION: Everyone with an interest has an opportunity to participate, and Treaty of Waitangi partnership obligations are honoured by the Crown and Māori
- DECISION-MAKING: Decisions about use and protection of water, and land uses which affect water, are made in a timely, cost-effective, integrative and adaptive manner
Limits need to address both cumulative water extraction and water quality impacts from the mix of upstream land uses and discharges. Objectives of limit-setting usually maintain sufficient flow and water quality to support aquatic life, recreation, iwi values and other uses authorised through consents and the regional plan.
Either your catchment has room for more allocation (lucky you!) or it is over-allocated. The latter requires claw-back, restoration or water augmentation. These measures restrict peoples’ perceived property rights, wallets or both. Over-allocation is always harder to remedy than setting limits early.
Limit-setting is a socio-political process informed by biophysical sciences and economics, even though we hydrologists would love to be in the driving seat. As discussed by Hugh Canard, in their three reports to government, the Land and Water Forum recognises the benefits of collaborative processes and of an integrated catchment management approach to limit setting. Judgements must be made to balance development opportunity and conservation interests, so ideally all stakeholder and iwi groups should be engaged in understanding the trade-offs involved.
Financial benefits for water and land uses are weighed against less tangible values such as the ability to swim, the habitat left for fish, landscape values and the mauri of the waters. As a trout fisher commented in a workshop for our ‘Freshwater Values Monitoring & Outcomes’ research programme, “I wake up in the morning and wonder what I’m going to lose today”.
The figure shows that we should expect limits to change over time. After all, knowledge about catchment dynamics is improving all the time (grey shaded). But more importantly, the balance of values considered important will change over time.
Once a catchment becomes fully allocated, we’re confronted with the ‘Re-Allocation Problem’: how to accommodate deserving new uses of water – or land, with consequential discharge implications – from within the legislated fully allocated block. This is where economic drivers can play a part. Allowing transfers of water or discharge allocations, provided the environmental and third party effects of the transfer are not made any worse, seems the best available mechanism. Maori, environmental and farming interests have various objections to ‘water trading’. The devil is in the detailed design of the policy. In the absence of an ability to transfer consents, we have to ask ourselves what other policy mechanism would address the Re-Allocation Problem. I don’t think the answer is to extend the overdraft.
Andrew Fenemor is a hydrologist and water management researcher with Landcare Research in Nelson