Small Water Impounding Project (SWIP) and Diversion Dam (DD): Overview and Benefits

Small Water Impounding Project (SWIP)

Definition

The Small Water Impounding Project (SWIP) involves constructing earthen dams across narrow depressions or valleys to create reservoirs. These structures capture and store rainfall and runoff during the rainy season, allowing for the stored water to be used for various purposes when needed.

Classification

The Small Water Impounding Management Committee (SWIM), formerly led by the Department of Public Works and Highways (DPWH), classifies SWIPs as earthen dams with a height no greater than 30 meters and a storage capacity not exceeding 50 million cubic meters. The Bureau of Soils and Water Management (BSWM) is responsible for providing technical assistance for dams that are 15 meters or lower in height, as mandated by the Agriculture and Fishery Modernization Act of 1997 (AFMA).

Role in Soil and Water Conservation

SWIPs play a crucial role in soil and water conservation by enhancing environmental services through:

• Flood Mitigation: Reducing the risk of flooding by controlling water runoff.
• Groundwater Recharge: Promoting the natural replenishment of groundwater resources, which is essential for the sustainability of local ecosystems and agriculture.
• Sediment Capture: Preventing soil erosion and trapping sediments to maintain soil fertility and enhance agricultural productivity.

Uses and Benefits of SWIP

SWIP serves multiple purposes, which include:

• Supplemental Irrigation: Providing water for irrigation, domestic use, and livestock, particularly in inaccessible upland areas and among vulnerable communities.

• Upland Productivity Enhancement: Supporting farmers in improving productivity while promoting sustainable agricultural practices.

• Aquaculture Support: Facilitating the culture of freshwater fish, shrimps, eels, and other native species, enhancing local livelihoods.

• Combating Malnutrition and Poverty: Contributing to food security and poverty alleviation in upland areas through improved agricultural practices.

• Flood Prevention: Acting as small-scale structures for flood control, ensuring year-round agricultural production and improved soil and water conservation.

• Groundwater Recharge: Enhancing the replenishment of groundwater and spring sources, benefiting domestic and agricultural use.

• Recreational Facilities: Offering local communities areas for swimming and picnicking, thus enhancing community well-being.

Ecological and Environmental Effects

The long-term environmental benefits of SWIPs include:

• Flood Control: Helping to manage excess water and reduce flood risks.

• Reduced Soil Erosion/Sedimentation: Protecting the landscape and maintaining soil quality.

• Water Moisture Conservation: Promoting agroforestry and supporting diverse agricultural practices in watersheds.

Diversion Dam (DD)

Definition

A Diversion Dam is a structure, typically made of concrete or rockfill, constructed across the channels of streams, creeks, or small rivers with a reliable flow. Its purpose is to raise the water level and facilitate the controlled diversion of water via gravity to adjoining farmlands or other areas of use.

Components

Key components of a diversion dam include:

• Watershed Area: The land area that collects rainfall and contributes runoff to the stream or river.

• Concrete Dam: Often configured as an ogee shape or broad crested weir, which helps manage the water flow effectively.

• Outlet Works: Systems that enable the controlled release of water.

• Irrigation and Canal Facilities: Infrastructure required to transport diverted water to agricultural fields.

Uses and Benefits of Diversion Dam (DD)

The Diversion Dam has several uses and benefits, including:

• Water Diversion: Effectively diverting all or part of the water from waterways for beneficial uses such as irrigation, livestock supply, fire control, municipal or industrial applications, renewable energy development, and recreational purposes.

• Damage Reduction: Diverting periodic damaging flows from one watercourse to another to reduce the potential for damage from floods.

• Crop Intensification and Diversification: Allowing farmers to enhance agricultural productivity through improved water management.

• Improved Farm Income: By ensuring reliable water supply and enhancing crop yields, diversion dams contribute to increased farm profitability.

Implementing Guidelines

Both SWIP and DD projects must adhere to the implementing guidelines outlined in Memorandum Order #16 Series of 2015 from the Department of Agriculture. These guidelines ensure effective planning, development, and sustainable management of water resources for agricultural and community benefit.

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For more information or specific inquiries about SWIP or DD projects, you are encouraged to consult with the Bureau of Soils and Water Management or your local agricultural office. These projects are vital in promoting sustainable water management, enhancing food security, and fostering community resilience!