Restoring urban drains to living streams

Is it worthwhile?

By Maksym Polyakov (University of Western Australia)


KEY MESSAGES:
  • Restoring open drains into wetland ecosystems is expensive
  • We examined the increased value of nearby houses to an urban drain restoration project in Perth to assess increased home value
  • We found homes within 200m of the restoration site increased in value by 4.7%, meaning benefits exceeded costs

As urban populations grow and cities expand, peri-urban bush is cleared, and wetlands are filled and drained to give way to new developments. As a result, creeks and streams are transformed into open drains retaining their capability to transmit storm water across the landscape (eventually connecting to major waterways), but losing their habitat, environmental, and recreational functions. In recent years, urban planners, local governments, community groups and local residents have started to restore these open urban drains into ‘living streams’. The drainage function is still there but the effort has, in many cases, created a fully functioning wetland ecosystem.

For the restoration of urban drains to living streams to be widely adopted, it is important to show that the benefits from restoration are greater than the costs. It is known that living streams provide a broad variety of benefits, and that some of these benefits, such as recreational and aesthetic benefits, are valued by local residents. Evidence shows that people are willing to pay higher prices for the houses in the vicinity of living streams in the same way that they are willing to pay more to be closer to local parks and nature reserves.

The impact of restoration projects on house prices can be determined via a statistical technique known as the hedonic pricing method. Whilst this might take a decade to realise, the increased property prices should trickle down to the local councils through the council rates to help fund such restoration projects.

Take the case of Bannister Creek Living Stream project located in the suburb of Lynwood in Perth Metropolitan Area. It was initiated by the Bannister Creek Catchment Group formed by local residents as well as staff of the City of Canning and the WA Department of Water. The management plan, drafted by Dr Judith Fisher in 1999, aimed to rehabilitate a section of the Bannister Creek main drain into a living stream that would, in addition to the flood mitigation function of the existing main drain, also provide local amenity benefits, improve catchment water quality, and slow the flow of water into the system such that the flow velocity during high rainfall events was at an acceptable level for public safety. The works were completed during 2000-2002. In approximately ten years, the living stream had evolved into a fully functioning wetland ecosystem (see images below).

Bannister Creek before the restoration (November 2000). (Photograph courtesy of SE Regional Centre for Urban Landcare.)

Bannister Creek before the restoration (November 2000).
(Photograph courtesy of SE Regional Centre for Urban Landcare.)

 

Bannister Creek after restoration had been completed (September 2013). (Photograph courtesy of SE Regional Centre for Urban Landcare.)

Bannister Creek after restoration had been completed (September
2013). (Photograph courtesy of SE Regional Centre for Urban
Landcare.)

We found that in the initial years of the restoration project the site would not have provided any local amenity benefits, and that there may have even been some dis-amenity effects due to extensive earthworks.

However, eight years after the restoration the median home within 200m of the project had increased in value by between $17,000 and $26,000 more than similar homes in the area. That’s an increase in value of 4.7%.

Once aggregated along the length of the restoration project, the benefits capitalised into local homes are found to be many times the cost of the restoration project. So, even without considering other values such as water quality or biodiversity benefits, the restoration of the drain to a living stream was worthwhile.


More info: Maksym Polyakov maksym.polyakov@uwa.edu.au

Reference: Polyakov M, J Fogarty, F Zhang, R Pandit & DJ Pannell (2016).
The value of restoring urban drains to living streams. Water Resources and Economics DOI:10.1016/j.wre.2016.03.002

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