Bioswales

ENTRY DATE: 04.05.2015 | LAST UPDATE: 04.05.2015

CATEGORIES:

  • Water Resources
  • Control of flood management and water use
  • Reclaimed water use
  • Water supply measures

TECHNOLOGIES MATURITY:

Exploration and research phases

Technology Owners:

  • Communities and land owners
  • Implementing and support agencies e.g. NGO, local government

Needs Address

  • Conservation of water resources
  • Traditional methods of water management

Adaptation effects

  • Increases water security and provides and additional source of water for agricultural purposes
  • Increases agricultural production and therefore food security and economic resilience
  • Reduces extent of storm water, thereby reducing flood impacts
  • Contributes to groundwater recharge
  • Reduces reliance on contaminated ground water sources

Overview and Features

Wet or dry depressions in the ground constructed using rocks and vegetation to treat and filter storm water runoff. Bioswales must be sloped to enable water to move through the system. They reduce pollutants in storm and rainwater runoff via recycling through natural processes that harness vegetative and soil based cycles

Cost

Dependent on materials used 

Energy source

Human resources to install and maintain

Ease of maintenance

  • Requires maintenance and monitoring to ensure maximised operation is maintained
  • Maintenance includes vegetation management, removal of sediment accumulation, damage reparation and replacement of rocks

Technology performance

  • Very effective for treating storm water when properly maintained
  • A 4m swale can reduce rainwater runoff on a road by 25 per cent

Considerations

  • Can be encouraged through appropriate training and awareness raising
  • Trained designers needed to design bioswales according to local context and geography
  • Can benefit from collaboration between communities, designers, climate scientists and governments to ensure sustainability in design and management  – should be designed in consideration of local climatic context and probable changes
  • Government incentives can encourage land owners to install bioswales on their land
  • Requires complex engineering and design knowhow

Co-benefit, suitability for developing countries

  • Reduced carbon emissions in comparison to alternative storm water treatment methods and centralised management systems
  • Less costly than centralised treatment systems
  • Limit flow of water into centralised management systems thereby saving energy
  • Ecologically sustainable and beneficial approach
  • Can be implemented, managed and maintained by communities
  • Can be constructed using locally available materials
  • Affordable to construct and maintain
  • Requires land ownership/ management authorisation
  • Not widely used as a technology in Asia-Pacific therefore will require comprehensive awareness raising, communication, training and marketing plans as well as financial support to introduce to developing countries

Information Resources

ADB, 2014. Technologies to Support Climate Change Adaptation in Developing Asia. Asian Development Bank. Available from: http://www.adb.org/publications/technologies-support-climate-change-adaptation-developing-asia [22 January 2015]

CRD, n.d. Bioswales. Webpage. Available from:  https://www.crd.bc.ca/education/low-impact-development/bioswales [22 January 2015]

Xiao, Q. and McPherson, E.G. 2009. Testing a Bioswale to Treat and Reduce Parking Lot Runoff. USDA. Available from: http://www.fs.fed.us/psw/programs/uesd/uep/products/psw_cufr761_P47ReportLRes_AC.pdf [22 January 2015]