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Agricultural Technology

Small Water Impounding Projects (SWIPs) for Rainwater Harvesting

Over the years, there has been an observed increase in the rainfall amount in the Philippines due to climate change. In order to take advantage of the abundant rainwater, small water impounding projects (SWIPs) are constructed to serve as water resources during drier seasons. SWIPs are structures that store and harvest rainwater, it includes an embankment and water outlet to keep the water from overflowing [1][3].

Climate Adaptation Effectiveness

Implementation of SWIPs is effective in mitigating floods by collecting and storing rainwater and surface runoff. When clusters of SWIPs for rainwater harvesting are constructed in an area, it could prevent large-scale flooding by reducing flood peak discharge. The stored rainwater is used as supplementary irrigation for farmlands during dry seasons and water source for aquaculture [1].

Climate Hazards

  • Drought
  • Extreme Rainfall
  • Rain-Induced Flooding
  • Rainfall Variability

Locations

  • Talugtog municipality, Nueva Ecija, Region III (Central Luzon)

Adaptation Sectors

  • Agriculture
  • Water Management

CCET Instuments

  • Action Delivery

Target Group based on Vulnerability

Basic Sectors:
  • Children
  • Farmers and Landless Rural Workers
  • Indigenous Peoples
  • Persons with Disabilities
  • Senior Citizens
  • Women
  • Youth and Students

Evaluations

Economic / Financial Effectiveness
Low

There is no upfront initial cost for the project because this is fully funded by the LGU. The rainwater harvested by the SWIPs is used as a water source for supplemental irrigation, inland fish production, livestock management, and for domestic and recreational uses. With an average age of 14 years (3 - 21 years), most SWIPs have reached an economic life of 25 years, with their main embankments still intact and no major structural damage. Spillways need regular cleaning and maintenance [1].

Technical Feasibility
Low

In Talugtog, Nueva Ecija, most of the SWIPs observed have been functioning for 25 years thus it would need a certain amount of upkeep. Although the majority are highly functional and are efficient, the spillways should be cleaned regularly. The embankments, outlet works, and control gate valves should also be regularly checked for maintenance and needed repairs. This is possible with the organization of a small water impounding system association (SWISA) who would be responsible for maintaining the SWIPs and coordinating with the LGU for funds [1].

Social Acceptability
Mid

SWIPs are highly accepted by farmers. In the past years, they have recognized its importance and requested the construction of SWIPs in their respective localities [1].

Environmental Impact
Mid (+)

The construction of SWIPs aid in flood mitigation and reduce soil erosion [1].

Mitigation co-benefit

Due to its contribution to agriculture, SWIPs preserve or maintain soil carbon stocks [3].

Keywords

small water impounding project, SWIPs, rainwater harvesting, store rainfall, store run off, flood control

References

[1] Contreras, S., Sandoval, T., and Tejada, S. (2013). Rainwater Harvesting, its Prospects and Challenges in the Uplands of Talugtog, Nueva Ecija, Philippines. International Soil and Water Conservation Research, 1(3), pp. 56-67. https://doi.org/10.1016/S2095-6339(15)30031-9
[2] DA-BSWM (n.d.) Small Water Impounding Project. http://bswm.da.gov.ph/download/small-water-impounding-project-swip/
[3] Dikitanan, R., Grosjean, G., Nowak, A., Leyte, J. (2017). Climate-Resilient Agriculture in the Philippines. CSA Country Profiles for Asia Series. International Center for Tropical Agriculture (CIAT); Department of Agriculture - Adaptation and Mitigation Initiatives in Agriculture, Government of the Philippines. Manila, Philippines. 24. https://cgspace.cgiar.org/handle/10568/82572