This post was prepared by Conservation Council volunteer Declan Tennent.
In the 1970s, after a devastating flood, Yarralumla Creek was straightened, deepened and lined with concrete to move water away from the Woden Valley as quickly as possible (Carrick 2025; CWEEP, n.d.). While this action may have made sense under the ACT Government’s previous planning mindset that treated creeks primarily as stormwater pipes; today, with a rapidly changing climate, a growing population and clear evidence of repeated flood impacts, we need to ask whether that single‑purpose approach is still fit for purpose. Yarralumla Creek is a critical part of the Molonglo catchment, Woden’s public realm and transport spine, flowing into Lake Burley Griffin and ultimately the Murrumbidgee River.
A hard lesson from the 1970s – and after
The 1971 Woden flood remains the defining warning against lining creekbeds with concrete. Around 100 mm of rain fell in about an hour, turning Yarralumla Creek into a torrent reportedly 180 – 200 metres wide. As some Canberrans may remember, seven young people tragically lost their lives at the Melrose-Yamba-Yarra Glen crossing, with the damage bill estimated at around $9 million at the time (Allen 2021; Region Canberra 2024). Much of the response involved more hardening: raising the Melrose roundabout and lining more of the creek with concrete in the name of safety.
Despite that investment, flooding has not disappeared. Several overbank events in the 2000s, damage to about 60 metres of concrete lining in an October 2022 flash flood, and more recent impacts around the Ivy apartments all point to a system under strain (Allen 2021; Fenwicke 2026). These events are clear signals that a long, straight, fast‑flowing concrete chute may be poorly matched to more intense, short‑duration storms and growing development pressure along the corridor.
Limits of the current model
The attractions of concrete are obvious: it is simple, predictable, and moves water away quickly. However, hard‑edged channels reduce habitat and ecological function (CWEEP, n.d.; ACT Government 2024b), disconnecting the creek from its floodplain and surrounding green space (ACT Government 2024b; Cunningham 2017). They also deliver high sediment and nutrient loads downstream and concentrate flood peaks rather than allowing flows to be slowed and spread (ACT Government 2024b; Díaz‑Redondo et al. 2021; NCEconomics 2019).
Renaturalisation – not return to wilderness, but better engineering
Renaturalisation, often loosely conflated with rewilding, is sometimes mischaracterised as simply “letting nature take over” or, at the other extreme, reduced to decorative landscaping. In reality, urban renaturalisation is usually a hybrid, nature-based solution, that is carefully engineered, with the explicit aim of reconnecting built spaces with their natural geographic setting (Pech 2016). In a creek corridor such as Yarralumla, that means reshaping parts of the channel to behave more like a creek and less like a chute. For example, using planted banks, meanders and riffles where space allows, and flood benches and wetlands to store water temporarily (Pech 2016; CSA Group 2021). It can also involve a suite of upstream measures such as rain gardens, swales and permeable surfaces to treat runoff before it reaches the main channel (Pech 2016; CSA Group 2021).
The fear that renaturalisation measures increase flood risk is understandable but misplaced. Well‑designed renaturalisation widens the effective cross‑section for flow, slows water and creates storage so peak flows are attenuated before they hit downstream pinch points like Melrose Drive (Pech 2016; ACT Government 2024a). The key difference is that concrete delivers water fast and all at once; a naturalised system aims to slow it down and spread it out.
When coupled with water-sensitive urban design (WSUD), renaturalisation can be even more effective at slowing, storing and treating water in urban environments. The ACT Government’s Water-sensitive Urban Design Guidelines describe WSUD as an approach that integrates management of the urban water cycle into planning and design, with the aim of reducing runoff, treating stormwater, using water more efficiently and improving the amenity of urban landscapes. In practice, that effectively means combining creek naturalisation with measures such as rain gardens, swales, permeable surfaces, wetlands, stormwater reuse and landscape features that retain water where it falls, rather than funnelling it rapidly downstream.
This matters because Yarralumla Creek should not be thought of as a stand-alone drainage problem. A concrete channel can only ever deal with the water that reaches it. WSUD helps reduce the speed, volume and pollution load of that water before it gets there. That is to say, renaturalisation works best when paired with upstream interventions across streets, public spaces and new developments, so the whole catchment starts to function more like a sponge and less like a pipe (Wong, Rogers & Brown 2020).
Tuggeranong Creek shows renaturalisation can work
The ACT Government’s Healthy Waterways program, jointly funded by the ACT and Australian Government has already successfully delivered renaturalisation works along Tuggeranong Creek, replacing concrete with more natural creek beds, pools, riffles and native planting while maintaining drainage function (ACT Government 2024a). Those works are explicitly aimed at improving habitat and water quality entering Lake Tuggeranong, and they sit within a broader catchment plan that combines infrastructure, behaviour change and monitoring (ACT Government 2024a).
An ex‑post evaluation by NCEconomics (2019) of the ACT Healthy Waterways program found that its package of wetlands, raingardens, stormwater assets and behaviour‑change delivered a benefit–cost ratio of about 1.66 – in other words, every dollar invested returned around $1.66 in quantified benefits such as water‑quality improvements, amenity and recreation gains, property‑value uplift and other co‑benefits. The lesson for Yarralumla Creek is not that the two sites are identical, but that the ACT already has a working model for staged, science‑based investment in urban waterways.
A staged solution for Yarralumla Creek
The solution is not tearing out every metre of concrete overnight. Full corridor transformation in a built‑up urban setting would be expensive and disruptive, and in some locations physically impossible because of existing utilities and roads.
A more realistic approach would be the staged renaturalisation of Yarralumla Creek. We recommend the ACT Government:
- Protect corridor space now in planning so options are not foreclosed by new buildings or infrastructure. If current planning proposals for housing and the light rail go ahead without reserving space for a different creek form, we risk “locking in” this vulnerability for another generation.
- Commission feasibility work such as hydraulic modelling, utilities mapping and concept design to identify where renaturalisation is technically and economically viable
- Combine channel changes with upstream water‑sensitive urban design (WSUD) to reduce inflows and pollution at the source; and
- Start with, and emphasise “early wins” such as edge softening, wetlands or detention basins, targeted planting and stormwater interventions where the risk–benefit balance is clearly favourable.
This kind of program aligns directly with the ACT Water Strategy’s objectives for water‑sensitive urban landscapes, climate‑resilient waterbodies and integrated catchment management (ACT Government, n.d.a; ACT Government, n.d.b). It also fits within national funding frameworks for urban rivers and catchments that are designed to support exactly this sort of staged, place‑based work (DCCEEW 2026).
Ultimately, investing in renaturalising Yarralumla Creek, through a staged, evidence‑based program, would:
- Reduce long‑term flood risk by slowing and storing water rather than simply propelling it downstream (Pech 2016; ACT Government 2024b);
- Cut sediment and nutrient loads entering the Molonglo–Murrumbidgee system (Díaz‑Redondo et al. 2021; Firoozi et al. 2026);
- Improve local biodiversity, urban cooling and amenity in a rapidly densifying district (ACT Government 2024b; Walsh et al. 2005); and
- Demonstrate that the ACT is prepared to align its planning and infrastructure decisions with its own water and climate strategies.
The real choice facing the ACT Government is not between a “natural” creek and a “safe” one. It is between continuing to rebuild an ageing, single‑purpose floodway that has already shown ruinous signs of failure, or taking the opportunity, while Woden is still being reshaped, to design a safer, greener and more resilient corridor.
Reference List
ACT Government (2024a) Community Consultation Paper: Developing a 10-year plan to restore Lake Tuggeranong. Community Consulation Paper.
ACT Government (2024b) Sullivans Creek Re-Naturalisation Options Report. ACT Government, Canberra.
ACT Government (n.d.a) Developing the next ACT climate change strategy | YourSay ACT. Available at: https://yoursayconversations.act.gov.au/climate-change-strategy (Accessed: May 11, 2026).
ACT Government (n.d.b) Draft Gungahlin District Strategy | ACT Planning System Review and Reform Project, YourSay ACT. Available at: https://yoursayconversations.act.gov.au/act-planning-review/draft-gungahlin-district-strategy (Accessed: May 11, 2026).
ACT Government (n.d.c) Sullivans Creek Re-naturalisation Plan | YourSay ACT. Available at: https://yoursayconversations.act.gov.au/sullivans-creek-re-naturalisation-plan (Accessed: May 11, 2026).
ACT Government (n.d.d) Sullivans Creek re-naturalisation plan – ACT Government. Available at: https://www.act.gov.au/environment/environment-projects/sullivans-creek-re-naturalisation-plan (Accessed: May 11, 2026).
ACT Government; PositionTitle=Director; SectionName=Corporate Management; Corporate=Chief Minister, T. and E.D.D. (2024) Naturalisation of Tuggeranong Creek improves habitat and waterway health, Chief Minister, Treasury and Economic Development Directorate. Chief Minister, Treasury and Economic Development Directorate. Available at: https://www.cmtedd.act.gov.au/open_government/inform/act_government_media_releases/rattenbury/2024/naturalisation-of-tuggeranong-creek-improves-habitat-and-waterway-health (Accessed: May 11, 2026).
ACT Legislative Assembly (2025) “ACT Legislative Assembly 2025, Debates of the Legislative Assembly for the Australian Capital Territory.” ACT: ACT Legislative Assembly. Available at: https://www.hansard.act.gov.au/hansard/11th-assembly/2025/PDF/tP251023.pdf.
Allen, C. (2021) Canberra marks 50 years from the Woden Valley flood which killed seven young people. ABC News. Available at: https://www.abc.net.au/news/2021-01-26/act3a-50-years-on-from-the-woden-flood-which-killed-seven/13074262 (Accessed: May 11, 2026).
CanberraDigest (n.d.) Tuggeranong Creek Re-naturalisation | CanberraDigest. Available at: https://canberradigest.com.au/articles/tuggeranong-creek-re-naturalisation (Accessed: May 11, 2026).
Central West Councils Environment & Waterways Alliance (2024) Urban Rivers and Catchments Program 2023 — Central West Councils Environment & Waterways Alliance, Urban Rivers and Catchments Program 2023 — Central West Councils Environment & Waterways Alliance. Available at: https://www.cwcewa.com.au/grants-award/2023/11/27/urban-rivers-and-catchments-program-2023 (Accessed: May 11, 2026).
Centre for Water Economics, Environment and Policy (CWEEP) (n.d.) Unconcreting and naturalising Sullivans Creek | Crawford School of Public Policy. Available at: https://crawford.anu.edu.au/cweep/unconcreting-and-naturalising-sullivans-creek (Accessed: May 11, 2026).
CityNews (2026) “Flash flooding restarts Yarralumla Creek debate,” Queanbeyan CityNews, 9 February. Available at: https://citynewsqbn.com.au/2026/flash-flooding-restarts-yarralumla-creek-debate/ (Accessed: May 11, 2026).
CRC for Water sensitive cities (2018) “Small Creek naturalisation – CRC for Water sensitive cities,” Case Studies – Small Creek naturalisation, 17 September. Available at: https://watersensitivecities.org.au/solutions/case-studies/small-creek-naturalisation-3/ (Accessed: May 11, 2026).
CRC for Water sensitive cities (n.d.) “Small Creek Naturalisation.” Available at: https://watersensitivecities.org.au/solutions/case-studies/small-creek-naturalisation-3/.
Cunningham, D. (2017) “Cooks River naturalisation.” Sydney Water.
Department of Climate Change, Energy, the Environment and Water (DCCEEW) (2026) Urban Rivers and Catchments Program. Australian Government. Available at: https://www.dcceew.gov.au/environment/biodiversity/conservation/urban-rivers-catchments-program (Accessed: May 25, 2026).
Díaz-Redondo, M. et al. (2022) “Naturalising a heavily modified urban river: Initial habitat evolution in the Manzanares River (Madrid, Spain),” River Research and Applications, 38(4), pp. 727–737. Available at: https://doi.org/10.1002/rra.3932.
Díaz-Redondo, M., Marchamalo, M. and Morcillo, F. (2021) “Hydromorphological effects of the renaturalization of an urban river: the Manzanares River in the city of Madrid (Spain) Effets hydromorphologiques de la renaturalisation d’une rivière urbaine : la rivière Manzanares à Madrid (Espagne).”
Fenwicke, C. (2026) Catchment-22: Why repairing the drain at Yarralumla Creek might be a washout, Region Canberra. Available at: https://region.com.au/catchment-22-why-repairing-the-drain-at-yarralumla-creek-might-be-a-washout/940759/ (Accessed: May 11, 2026).
Fenwicke, C. (no date) “Aspirational” $300m re-naturalisation project for Sullivans Creek shelved. Region Canberra. Available at: https://region.com.au/aspirational-300m-re-naturalisation-project-for-sullivans-creek-shelved/900352/ (Accessed: May 11, 2026).
Fiona Carrick Independent (2025) YARRALUMLA CREEK—RE-NATURALISATION OPTIONS REPORT AND PROTECTION, Fiona Carrick Independent. Available at: https://www.fionacarrick.com/motion-251023-yarralumla-ck-re-naturalisation (Accessed: May 11, 2026).
Firoozi, A.A., Firoozi, A.A. and Saidani, T. (2026) “Advancing sustainable water management: The pivotal role of civil engineering in navigating environmental and urban challenges,” Alexandria Engineering Journal, 137, pp. 360–385. Available at: https://doi.org/10.1016/j.aej.2026.01.034.
Gobert, J. (2023) “Climate change and rivers: The promise offered by infrastructure,” Total Environment Research Themes, 8, p. 100077. Available at: https://doi.org/10.1016/j.totert.2023.100077.
Guimarães, L.F. et al. (2021) “The challenges of urban river restoration and the proposition of a framework towards river restoration goals,” Journal of Cleaner Production, 316, p. 128330. Available at: https://doi.org/10.1016/j.jclepro.2021.128330.
Natural Capital Economics (NCEconomics) (2019) ACT Healthy Waterways: Economic analysis. Report to the ACT Government’s Directorate of Environment, Planning and Sustainable Development.
Pech, P. (2016) Renaturalisation. HyperGeo. Available at: https://hypergeo.eu/renaturalisation/?lang=en (Accessed: May 11, 2026).
Region Canberra (2024) Did Saturday’s wild weather just break Woden’s 1-in-100-year flood risk? | Region Canberra. Available at: https://region.com.au/did-saturdays-wild-weather-just-break-wodens-1-in-100-year-flood-risk/736740/ (Accessed: May 11, 2026).
Vouk, I. et al. (2021) Nature-Based Solutions for Coastal and Riverine Flood and Erosion Risk Management. Toronto, ON.: Canadian Standards Association (CSA Group). Available at: https://www.csagroup.org/article/research/nature-based-solutions-for-coastal-and-riverine-flood-and-erosion-risk-management/?srsltid=AfmBOoo1u9sHmXyj5IdY4y6lrBCwXPykSzxKz86UHA_HT12lpqOW_75r (Accessed: May 25, 2026).
Walsh, C.J. et al. (2005) “The urban stream syndrome: current knowledge and the search for a cure,” Journal of the North American Benthological Society, 24(3), pp. 706–723. Available at: https://doi.org/10.1899/04-028.1.
Wong, THF, Rogers, BC & Brown, RR 2020, ‘Transforming cities through water-sensitive principles and practices’, One Earth, 3(4), pp. 436–447, viewed 22 June 2026, doi:10.1016/j.oneear.2020.09.012.
World Economic Forum (2026) What Is Natural Rewilding, And Can It Save Our Forests?, World Economic Forum. Available at: https://www.weforum.org/videos/what-is-rewilding-and-can-it-save-our-forests/ (Accessed: May 11, 2026).