Aotearoa BiodiverCity / Design Guide / Design Strategies /

Urban blue spaces

SCALES / ,
SYNERGIES / , ,

CASE STUDIES //

An urban blue space — a river, wetland, or pond integrated into the city providing aquatic habitat and supporting water species, invertebrates, and birds in Aotearoa New Zealand.

Definition

Urban blue spaces are water bodies and water-dependent habitats within urban areas that support aquatic and semi-aquatic biodiversity and ecological processes.

What this strategy does

Integrates rivers, streams, wetlands, ponds, and coastal edges into urban form to provide habitat, improve water quality, and maintain hydrological and ecological connectivity, while managing human use and urban pressures.

Context

In Aotearoa New Zealand, urbanisation has significantly modified freshwater systems, contributing to habitat loss, fragmentation, and declining water quality. Strategic design and restoration of urban blue spaces is therefore critical for Indigenous biodiversity, freshwater security, and climate resilience.1, 2

Technical considerations

Design considerations

Habitat connectivity

Design blue spaces as part of a connected network, using corridors and stepping stones to enable movement of aquatic and semi-aquatic species across urban landscapes.1, 3, 4

Native vegetation and habitat complexity

Prioritise Indigenous riparian and wetland vegetation and structurally diverse habitats, including variable water depths and hydroperiods, to support a range of native taxa.5, 6

Water quality and hydrology

Protect and restore natural hydrological regimes by managing stormwater inputs, reducing contaminant loads, and integrating water-sensitive design features such as wetlands, swales, and rain gardens.7, 8, 9

Scale and spatial planning

Plan blue space interventions at both site and catchment scales, using spatial analysis to optimise patch size, configuration, and proximity to other green and blue spaces.2, 4

Human use and social interface

Balance recreational access with ecological function through zoning, planting buffers, and community stewardship to reduce disturbance and pollution.7, 10

Implementation considerations

Design priority

Protect existing freshwater habitats first, then restore degraded systems before creating new blue spaces.

Key constraint

Urban stormwater contamination and altered hydrology can limit ecological performance if not addressed at a catchment scale.8, 11

Issues & barriers

Habitat loss and fragmentation

Urban densification reduces permeable surfaces and disrupts freshwater connectivity, limiting biodiversity gains where restoration is isolated.2, 12

Water pollution

Stormwater-derived nutrients, sediments, and heavy metals continue to degrade urban freshwater ecosystems.8, 11

Invasive species and predation

Blue spaces are vulnerable to invasive aquatic plants and animals, constraining the recovery of Indigenous species.5, 13

Knowledge and monitoring gaps

Limited empirical evidence exists on optimal blue space configurations for native species under urban stressors.9, 14

Policy and planning limitations

Inconsistent biodiversity targets and weak protection of freshwater margins reduce long-term effectiveness.12, 15

Synergies & opportunities

Climate change

Blue spaces contribute to urban cooling, flood attenuation, and climate adaptation when integrated with green infrastructure.16, 17

Human wellbeing

Access to water environments supports mental health, recreation, and cultural practices, including mahinga kai, when designed inclusively.16, 18

Freshwater security

Healthy blue spaces improve water quality and resilience of urban freshwater systems through natural filtration and storage processes.7, 17

Financial case

Ecosystem services and performance value

Value type

Reduced flood damage, lower stormwater infrastructure costs, improved water quality, and avoided public health costs.17, 19

Cost-effectiveness

Investment logic

Aotearoa New Zealand evidence indicates that riparian and wetland restoration can deliver high benefit–cost ratios, even without directly monetising biodiversity benefits.19

Monitoring & evaluation metrics

Core metric

Water quality indicators (nutrients, suspended solids, heavy metals), habitat extent and Indigenous vegetation cover.8, 20

Advanced or long-term metric

Macroinvertebrate Community Index (MCI), indicator species presence, and eDNA-based biodiversity assessments.21, 22

Additional resources or tools

New Zealand

NUWAO Urban Guide to Blue–Green Space

Practical guidance for integrating blue–green infrastructure in urban design.

Wellington Urban Design Toolkit

Design guidance for urban environments, including water-sensitive design.

References
  1. Nguyễn, T., Meurk, C., Benavidez, R., Jackson, B., & Pahlow, M. (2021). The effect of blue–green infrastructure on habitat connectivity and biodiversity: A case study in the Ōtākaro/Avon River catchment in Christchurch, New Zealand. Sustainability, 13(12), 6732. https://doi.org/10.3390/su13126732
  2. Clarkson, B., Wehi, P., & Brabyn, L. (2007). A spatial analysis of indigenous cover patterns and implications for ecological restoration in urban centres, New Zealand. Urban Ecosystems, 10, 441–457. https://doi.org/10.1007/s11252-007-0035-6
  3. Donati, G., Bolliger, J., Psomas, A., Maurer, M., & Bach, P. (2022). Reconciling cities with nature: Identifying local blue–green infrastructure interventions for regional biodiversity enhancement. Journal of Environmental Management, 316, 115254. https://doi.org/10.1016/j.jenvman.2022.115254
  4. Hyseni, C., Heino, J., Bini, L., Bjelke, U., & Johansson, F. (2021). The importance of blue and green landscape connectivity for biodiversity in urban ponds. Basic and Applied Ecology, 55, 24–36. https://doi.org/10.1016/j.baae.2021.10.004
  5. Oertli, B., & Parris, K. (2019). Toward management of urban ponds for freshwater biodiversity. Ecosphere, 10(7), e02810. https://doi.org/10.1002/ecs2.2810
  6. Van Roon, M. (2012). Wetlands in the Netherlands and New Zealand: Optimising biodiversity and carbon sequestration during urbanisation. Journal of Environmental Management, 101, 143–150. https://doi.org/10.1016/j.jenvman.2011.08.026
  7. McLeod, L., Hine, D., Milfont, T., et al. (2024). Protecting and restoring freshwater biodiversity across urban areas in Aotearoa New Zealand: Citizens’ reporting of pollution in stormwater drains and waterways. Journal of Environmental Management, 351, 120019. https://doi.org/10.1016/j.jenvman.2024.120019
  8. Chakravarthy, K., Charters, F., & Cochrane, T. (2019). Impact of urbanisation on New Zealand freshwater quality. Policy Quarterly, 15(3). https://doi.org/10.26686/pq.v15i3.5683
  9. Muñoz, S., Schoelynck, J., Tetzlaff, D., et al. (2024). Assessing biodiversity and regulatory ecosystem services in urban water bodies which serve as aqua-nature-based solutions. Frontiers in Environmental Science, 11, 1304347. https://doi.org/10.3389/fenvs.2023.1304347
  10. Alikhani, S., Nummi, P., & Ojala, A. (2021). Urban wetlands: A review on ecological and cultural values. Water, 13(22), 3301. https://doi.org/10.3390/w13223301
  11. Clapcott, J., Collier, K., Death, R., et al. (2012). Quantifying relationships between land-use gradients and indicators of stream ecological integrity. Freshwater Biology, 57, 74–90. https://doi.org/10.1111/j.1365-2427.2011.02696.x
  12. Varshney, K., MacKinnon, M., Zari, M., et al. (2024). Biodiverse residential development: A review of New Zealand policies and strategies for urban biodiversity. Urban Forestry & Urban Greening, 89, 128276. https://doi.org/10.1016/j.ufug.2024.128276
  13. Rastandeh, A. (2018). Urban biodiversity in an era of climate change: Towards an optimised landscape pattern in support of indigenous wildlife species in urban New Zealand. Victoria University of Wellington. https://doi.org/10.26686/wgtn.17134823.v1
  14. Prodanović, V., Bach, P., & Stojković, M. (2024). Urban nature-based solutions planning for biodiversity outcomes. Urban Ecosystems. https://doi.org/10.1007/s11252-024-01558-6
  15. Jang, J., & Woo, S. (2022). Native trees as a provider of vital urban ecosystem services in New Zealand. Land, 11(1), 92. https://doi.org/10.3390/land11010092
  16. Almaaitah, T., Appleby, M., Rosenblat, H., et al. (2021). The potential of blue–green infrastructure as a climate change adaptation strategy. Blue-Green Systems, 3(3), 447–465. https://doi.org/10.2166/bgs.2021.016
  17. McNabb, T., Charters, F., Challies, E., & Dionisio, R. (2024). Unlocking urban blue–green infrastructure: An interdisciplinary review. Blue-Green Systems, 6(1). https://doi.org/10.2166/bgs.2024.007
  18. Mihaere, S., Holman-Wharehoka, M., Mataroa, J., et al. (2024). Centring localised indigenous concepts of wellbeing in urban nature-based solutions. Frontiers in Environmental Science, 12, 1278235. https://doi.org/10.3389/fenvs.2024.1278235
  19. Daigneault, A., Eppink, F., & Lee, W. (2017). A national riparian restoration programme in New Zealand: Is it value for money? Journal of Environmental Management, 187, 166–177. https://doi.org/10.1016/j.jenvman.2016.11.013
  20. Death, R., & Collier, K. (2009). Measuring stream macroinvertebrate responses to gradients of vegetation cover. Freshwater Biology, 55, 1447–1464. https://doi.org/10.1111/j.1365-2427.2009.02233.x
  21. Zhang, S., Zhao, J., & Yao, M. (2023). Urban landscape-level biodiversity assessment using environmental DNA metabarcoding. Journal of Environmental Management, 340, 117971. https://doi.org/10.1016/j.jenvman.2023.117971
  22. Chaparro-Herrera, D., Fuentes-García, R., Hernández-Quiróz, M., et al. (2021). Comprehensive health evaluation of an urban wetland using quality indices. Environmental Monitoring and Assessment, 193, 561. https://doi.org/10.1007/s10661-021-08939-w