UFTI Constraints Mapping Report
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UFTI Constraints Mapping Report 19 December 2019 Contents 1. Purpose of the UFTI constraints mapping project ........................................................ 2 2. Western Bay of Plenty sub-region area of focus .......................................................... 2 3. Structure and style of UFTI constraints mapping .......................................................... 2 4. Natural Hazards – general explanation of approach taken in UFTI constraints mapping ................................................................................................................................... 5 5. No Go layers ..................................................................................................................... 7 6. Go Carefully layers ......................................................................................................... 11 7. Other land use consideration layers ............................................................................ 18 8. Blue/green network ....................................................................................................... 18 Appendix 1 - Data sources for No Go, Go Carefully, and Blue/Green Network layers .................................................................................................................................................. 19 A3443384 1 1. Purpose of the UFTI constraints mapping project This work supports the Urban Form and Transport Initiative (UFTI) project by identifying areas that are not suitable for urban development (‘no go’ areas) and other areas where there are constraints that need to be carefully considered as part of spatial planning work (‘go carefully’ areas). 2. Western Bay of Plenty sub-region area of focus The Western Bay of Plenty sub-region area consists of the Western Bay of Plenty District and Tauranga City Council territorial authority areas. 3. Structure and style of UFTI constraints mapping The UFTI constraints mapping work has been structured in a similar way to the Hamilton to Auckland (H2A) Corridor Plan, where the Mapping Project was carried out by Waikato Regional Council. Similar to H2A, UFTI has identified 1. No go areas – areas that should not be considered for development. 2. Go carefully areas – areas where additional consideration is required if development is contemplated. This includes areas which would likely include risk reduction and mitigation of any natural hazard susceptibility. 3. Blue/green areas - spatial layers that form the basis of an environmental and recreational network, and will assist in the enhancement of that network in future planning. Constraints/considerations are informed by established policy direction e.g. the Bay of Plenty Regional Policy Statement, regional plans, and district/city plans. We have used the best available data held by Bay of Plenty Regional Council, territorial authorities and national agencies. This report relates to the High Level Map of UFTI Layers dated 18/12/2019. A copy of this map is provided on page 4. Explanation of Layers ‘No go’ constraints are based on natural hazards, significant ecological sites and protected areas. Under each of these ‘no go’ spatial limits are a number of attributes. The various attributes and reasons why they have been classified ‘no go’ areas are explained in the following sections of this document. A3443384 2 We have deemed some areas ‘no go’ because they are either unsafe to develop, or have significant values to protect. ‘Go carefully’ attributes highlight the need for additional consideration in an area. We interpret ‘go carefully’ as those attributes where natural hazard susceptibility has been identified but where further assessment undertaken as part of future growth planning, and the application of mitigation options, can be applied to reduce risk. Go carefully attributes have the potential to impact on development if not carefully planned for, or engineered around. Attributes vary depending on location and some areas contain multiple attributes that, when combined, could render an area unsuitable for development. ‘Blue/green network’ are spatial layers that provide a starting point for enhancing a blue/green network and assist in identifying opportunities to leverage the benefits or enhance the values of the network. ‘Base layers’ have been included to all of the apps to provide viewing context for the various attributes. Base layers were not included in the analysis for the overall polygons. These are self-explanatory so additional information is not included, for example these include state highways and rail lines. A3443384 3 A3443384 4 4. Natural Hazards – general explanation of approach taken in UFTI constraints mapping Disclaimer - The natural hazard layers used in the UFTI maps are not a natural hazard assessment required for detailed structure planning in accordance with the Bay of Plenty Regional Policy Statement. The information in this section is relevant to natural hazard attributes in both the ‘No Go’ and ‘Go Carefully’ layers. We have used the best available data to inform constraints mapping for the sub- region. Tauranga City Council is progressing a Citywide Natural Hazards assessment and new data is expected early 2020 for the City. Western Bay of Plenty District Council is undergoing a similar exercise and new data for some hazards will be available around the same time. Natural hazard scenarios in the ‘No Go’ and ‘Go Carefully’ layers are explained in the table below. This is based around constraint mapping criteria relevant to the purposes of UFTI and likelihood of the natural hazard , which is consistent with the approach in the Regional Policy Statement. The criteria are also consistent with Policy 25 of the New Zealand Coastal Policy Statement 2010 (NZCPS) in relation to land use planning in areas at risk of coastal hazards. Hazard No Go or Criteria used for constraint mapping Likelihood for initial analysis Go required in RPS (for Carefully Greenfield Development) Open Coast No go 100yr ERZ 1% AEP (once in 100yr ARI) – Coastal Erosion Note: likelihood does not include P66% taken as P66% EP in 100 years EP or 1.6m SLR scenario as there is no (including 1.6m SLR scenario) greenfield potential in the coastal hazard areas. Applying criteria required for new greenfields to existing urban areas would see them classified as ‘no go’ areas. Inner Harbour No go 2130 P5% EP (including 1.25m SLR 1% AEP (once in 100yr ARI) – Coastal Erosion – scenario) taken as P66% EP in 100 years Note: the likelihood criteria has been (including 1.6m SLR scenario) reduced to P5% EP (including 1.25m SLR) because there is no greenfield potential in the coastal hazard area and also to align with TCC building consent requirements. Inner Harbour Go 2130 MHWS (including 1.25m SLR n/a Permanent Coastal carefully scenario) Inundation (Climate change) Inner Harbour Go 2130, 1% AEP + 1.25m SLR scenario 1% AEP (once in 100yr ARI) + Coastal Inundation carefully Note: SLR has been reduced to 1.25m 1.6m SLR scenario (Climate change because there is no greenfield potential and storm event) in the inner harbour coastal inundation area. A3443384 5 Hazard No Go or Criteria used for constraint mapping Likelihood for initial analysis Go required in RPS (for Carefully Greenfield Development) Tsunami Go 0.1% AEP + 1.25m SLR scenario 0.1% AEP (once in 1,000yr ARI) Inundation carefully Note: SLR has been reduced to 1.25m + 1.6m SLR scenario because there is no new greenfield potential in the coastal hazard areas (excluding planned urban growth areas at Te Tumu where all natural hazards have been assessed as part of robust structure planning process). Slope Instability Go 2H:1V upslope, and Rainfall - 1% AEP (once in carefully 4H:1V down slope 100yr ARI) Seismic - 0.1% AEP (once in 1,000 yr ARI) AEP = Annual Exceedance Probability: this is the probability of a certain event occurring in a single year. ARI = Average recurrence interval (time between events) SLR =Sea level rise Ministry for the Environment Coastal Hazards and Climate Change Guidance for Local Government New Zealand Coastal Policy Statement Guidance Note: Coastal Hazards – Objective 5 and Policies 24,25,26 &27 Definitions of terms related to ‘likelihood’. P5% Exceedance Probability (EP) = extremely unlikely with a 5 percent probability of being exceeded over a planning timeframe. P66% Exceedance Probability (EP) = likely with a 66 per cent probability of being exceeded over a planning timeframe. A3443384 6 5. No Go layers Refer to Appendix 1 for the table documenting the sources of information for the No Go layers. No go natural hazard layers NO GO layers: • Open coast coastal erosion • Inner harbour coastal erosion No go natural hazards layers are where there is an assessed probability (expressed as a likelihood) of the permanent loss of land (from erosion) if sea level rise occurs to the assessed levels. Mitigation of coastal erosion is expensive and often difficult. Refer to Appendix 1 for the table documenting the sources of information for the layers listed above. The Tauranga City Plan and Western Bay of Plenty District Plan 100 year erosion zones have been included in the constraints mapping. As part of a wider hazard research programme, a recent joint study between Tauranga City Council, Western Bay of Plenty District Council and the Bay of Plenty Regional Council was undertaken. It looked at erosion processes on inner harbour landforms (cliffs/shores) and estimated erosion rates for the entire inner Tauranga Harbour. The study shows the potential