Climate Resilient Irrigation Scheme
Type: Technologies
Creation: 2023-07-12 14:49 Updated: 2024-06-04 14:52
Compilers: Tshering Yangzom
Reviewers: William Critchley, Rima Mekdaschi Studer, Joana Eichenberger
Country/ region/ locations where the Technology has been applied and which are covered by this assessment
- Country: Bhutan
- Region/ State/ Province: Khomshar Chiwog, Bardho Gewog, Zhemgang Dzongkhag
- Map: View Map
Description of the SLM Technology
Short description of the Technology
A climate-resilient irrigation scheme is one that aims to successfully cope with and manage the impacts of climate change while preventing those impacts on the scheme from growing worse. The pipes are retrofitted with new and climate-resilient technology. Such a climate-proof irrigation system is designed to better withstand extreme weather conditions.
Detailed description of the Technology
The climate-resilient irrigation scheme in Khomshar Chiwog under Bardho Gewog (Block), Zhemgang Dzongkhag (District), was funded by the Green Climate Fund (GCF), UNDP-Bhutan. The 3.9 km irrigation system was designed with a high-density polyethylene (HDPE) pipe system benefiting 150 households with a command area of 955 acres (approx. 386 ha). The total irrigation cost incurred was Nu. 18,055,180 (approx. USD 225,700) and was completed in 11 months (7 December 2020 - 7 November 2021). The irrigation scheme was officially handed over to the community on 27 August 2021, upon the formation of a water-user group (WUG).
The smart irrigation system consists of key components, viz. intake, sluice gate, silt-cum-inlet tank, flush-out valves, air release valve, water distribution points, and tail point. The intake collects and diverts the water from the source to the sluice gate. The land users were taught to maintain the intake by regularly clearing it from bushes and removing debris. The sluice gate controls the flow of the water into the tank based on the water requirement. The silt-cum-inlet tank holds the water to settle out sediments and debris before clean water flows through the pipe at a constant rate. Flush out valves clear the sediment and debris from the tank. The air release valve vents out the air trapped in the pipe and water distribution points. Water distribution points deliver water to the users, as required, up to the tail point where water is discharged.
The irrigation scheme fulfils the need for a continuous water supply for both drinking and irrigation purposes. To ensure sustainability, a WUG headed by a chairman, a secretary, and a treasurer was instituted. The WUG ensures operations, maintenance, and harmonious distribution of water. The group is also responsible for the safety of the irrigation system.
The main reason for considering such irrigation scheme as being “climate resilient” is that unlike open earthen channels, this type of irrigation scheme results in zero loss of water through evaporation and leakage, as it is a closed channel. Furthermore, being closed, it is not prone to blockages caused by landslides triggered by rainfall. There is also complete end-to-end management, i.e., management at source including the watershed, and management at tail-end.
The irrigation scheme was constructed by a private company through a contract award: community members were not involved. The irrigation scheme was also accompanied by a land development programme (bench terracing) by a separate contractor, with the prospect of transitioning to irrigated paddy cultivation in the future after adequate soil stabilization. More than 90 acres (36 ha) of fallow lands were revived. This blended approach was applied to ensure the food self-security/sufficiency of the beneficiaries.
Though at a very initial stage, the construction and operation of the irrigation scheme have brought happiness to the beneficiaries. They expressed their hope and expectation of improved crop production, stable and reliable water availability, and major fallow land reversion.
Photos of the Technology
- 📍 Khomshar Chiwog (Community), Bardho Gewog (Block), Zhemgang Dzongkhag (District)
- 📷 Kuenzang Nima
- 📍 Khomshar Chiwog (Community), Bardho Gewog (Block), Zhemgang Dzongkhag (District)
- 📷 Kuenzang Nima
- 📍 Khomshar Chiwog (Community), Bardho Gewog (Block), Zhemgang Dzongkhag (District)
- 📍 Khomshar Chiwog (Community), Bardho Gewog (Block), Zhemgang Dzongkhag (District)