Water Pans / Dams
Water pans, also known as earth dams or rainwater harvesting structures, are designed to capture and store rainwater runoff from nearby catchment areas. These structures serve several vital purposes:
Agricultural Irrigation: Water pans provide a reliable source of water for crop irrigation, enabling year-round farming and improving agricultural productivity.
Livestock Watering: They ensure a steady supply of water for livestock, improving animal health and facilitating dairy and meat production.
Domestic Use: Water pans can be a source of clean drinking water for local communities, reducing the burden of water collection.
Erosion Control: They help control soil erosion by capturing runoff water, and preventing land degradation.
Rana ltd Key Steps & Considerations:
1. Planning & Permits:
Site Selection: Choose a stable location with good runoff potential.
Dimensions: Determine size based on land area to irrigate and local evaporation rates, sometimes using apps for calculation.
Purpose: Decide if for irrigation, livestock, or both.
2. Excavation:
Machinery: Use excavators and bulldozers for efficient digging and shaping.
Depth & Shape : Dig to desired depth (e.g., 5m+) with careful contouring for maximum storage.
Soil Management : Move excavated soil to form bunds or spread it.
Lining & Sealing (Crucial for water retention):
Clay Core: Compact clay-rich soil in the pan's base and walls to form an impermeable layer.
Liners: Install geotextile fabric or plastic liners if soil is too porous, using equipment to ensure a watertight seal.
Erosion Control: Line outer slopes with rocks, gravel, or concrete to prevent soil loss.
Inlets/Outlets & Infrastructure:
Control Structures: Build concrete inlets and outlets to manage water flow.
Access: Create access roads for construction and maintenance.
Community Points: Add troughs for animals or drawing points for farmers.
Post-Construction:
Community Handover: Often handed over to local communities for management.
Maintenance: Regular upkeep is needed to keep the pan functional.
Materials Used:
Soil: Main material, needs good clay content.
Clay: For sealing.
Rocks & Gravel: For slope protection.
Concrete: For structures.
Geotextile Fabric/Plastic Liners: To enhance impermeability.