Understanding how the Tauranga Harbour behaves as a system

What were the Parameters?


1950 to 2070
Tauranga Harbour and its catchments
Population Pressures
Natural Capital
Ecosystem Values
Economic and Agency Spend
Recreational Value of Tauranga Harbour
Pollutant Loads on Tauranga Harbour
Water Dynamics of Tauranga Harbour and its Catchments


The 3 big issues (symptoms) affecting the Harbour that emerged from the MTM workshops

  1. Sedimentation
  2. Eutrophication; (Human Effects on the Environment)
  3. Loss of things such as Kaimoana, habitat loss. The inherent processes/factors that are causing these issues are increased industrial/economic activity depleting ecosystems and their services; coastal development and urban pressures and associated pollution; system not “counting” ecosystem services.

What are the indicators of a sustainable harbour

Ecological (natural): Water in harbour that is same quality as at uppermost part of catchment, ie clear, drinkable, sustains life.

Social: Valued uses of harbour can still occur. Eg fishing; Mana-enhancing social systems reliant on the harbour, such as ability to collect kaimoana, are intact.

Cultural: Mauri of harbour is sustained?

Economic The value of ecosystem services is accounted for in the economic system, with appropriate incentives and regulations, so that use of natural resources is sustainable and does not erode natural capital upon which the economy depends, thus enabling ongoing but sustainable “economic” activity in region.

What do we need to change to help implement the solutions

  • Heavy “users” of ecosystems, or groups/industries that benefit from ecosystem services provided by the harbour, should also contribute to the maintenance/restoration of those ecosystems. Eg through funds set up specifically for ecosystem services, via taxation or levies on ecosystem goods and services.
  • System adapted via incentives/taxes to encourage individuals/groups to engage in restoration efforts, or limit unsustainable use of ecosystems.

Example of Expertise and dataset: Dr. Mel Green - Sedimentation Research, Southern half of Tauranga Harbour

Dr. Mel Green presented research done at NIWA on sedimentation in the Southern half of the Tauranga Harbour.  His model ran scenarios from 2001 to 2051, examining sediment yield per unit area.

The conclusions include:

  • 64% sediment runoff comes from pastoral land use; less than 0.5% from earthworks.
  • Over next 50 years, it is predicted that sedimentation will decrease 5.6% due to land use change: i.e. increased pavement and hard surfaces reduce the runoff of sediment, but increase the runoff of toxics.
  • However, when climate change (increased high intensity rainfall events) is taken into account, sedimentation will increase by 40.6%.  The effects of climate change magnify sedimentation.

Highlight of Process: Neutral Space

  • The "neutral" space fostered a constructive dialogue amoung stakeholders whom are often involved in more formal (and adversial) processes.
  • Learning among the stakeholders occurred.
  • Participants showed an interest in the modelling during the process and the dialogue was structured due to the modelling process. However, participants want to experiment hands-on with the model only when it is complete.
The 3 big issues (symptoms) affecting the Harbour that emerged from the MM workshops were