Diversion Channels
ENTRY DATE: 03.05.2015 | LAST UPDATE: 03.05.2015
CATEGORIES:
- Disaster Prevention
- Construction of infrastructure
TECHNOLOGIES MATURITY:
Applicable immediately
Technology Owners:
- Construction companies
- Communities
- Governments
Needs Address
Reduction of flood disasters, erosion or landslides
Adaptation effects
Protects community and agricultural land
Overview and Features
Diversion channels enable the rechanneling of up-slope water in order to avoid flood disasters, erosion and landslides. The channels divert water to another course and direct excess water to bedrock areas in order to dissipate the force of water flows. They are often constructed with stone, with locally available materials.
Figure 1: Stone Diversion Channel (Source: Sthapit and Tennyson, n.d.)
Cost
Construction costs
Energy source
Human resources and equipment for construction and maintenance
Ease of maintenance
- Continuous maintenance necessary, particularly after large water and debris surges – in the form of construction and clearing of channels
- Maintenance costs (e.g. cost of USD 6,653 to clear and upgrade 1.5km of mudflow diversion channel in Hayoti Nav, Tajikistan) (UNDP, 2012)
Technology performance
It is estimated that 1.5 km of cleared diversion channel in Tajikistan helped to protect 250 households and 330 hectares of agricultural land (UNDP, 2012.)
Considerations
- Critical to ensure comprehensive planning processes – e.g. that diverted water does not put new pressure on a different area or unbalance the geological dynamics of the site
- Requires multi-stakeholder cohesion and collaboration to identify problem areas, plan construction, finance, manage and maintain – communities should be an integral part of the process
Co-benefit, suitability for developing countries
- Can be used as part of a water management system
- Can be community-constructed and owned, enabling increased sustainability
- Can be constructed from locally available materials
Information Resources
Sthapit, K.M. and Tennyson, L.C. n.d. Bio-engineering erosion control in Nepal. FAO. Available at: http://www.fao.org/docrep/u1510e/u1510e04.htm [28 December 2014]
UNDP, 2012. Community Resilience to Disasters through Micro-Loan Supported Risk Management Funds. Available at: http://www.tj.undp.org/content/tajikistan/en/home/ourwork/crisispreventionandrecovery/successstories/community-resilience-to-disasters-through-micro-loan-supported-r/ [19 March 2015]