Irrigation at Shalom Estate

Thona [Natural Rainwater Drainage Channels] Pronounced “Thonaa”, these are natural waterways that have existed from time immemorial.

These are exclusive to parts of Batticaloa and Ampara districts. Starting from Kalkudah in the North of Batticaloa, one can find them all the way to Akkaraipatuu in Ampara district.

• Water from monsoonal rains drain to the sea
• Controls flooding by draining our excess water
• Keep the ground water levels in the vicinity, higher than other places and fresh
• Thonas have small ponds along the way and have particular trees and brush growth. This attracts rare fauna and flora, hence are protected.

Shalom Irrigation System

The source of water:

• Large agriculture well
• Tube wells sunk in various locations
• 3 phase electric pumps [10 Amp 10HP, ] manufactured by Solex in Sri Lanka are in use for pumping of water from a 15 feet wide agriculture well. They develop a head of 60 meters and  discharge 3,500 litres per hour.
• We do not use gravity to build pressure but use ground pumps with very high delivery head to build pressure.
• Coconut is irrigated by an irrigation system using 100Ltr/Hour spray jets.
• Water is carried by a 2inch PVC main line to 1.5 inch sub-main lines. 20mm LDPE run from the sub-main line along the coconut tree. Spray-jets are connected to these lines.
• A 2” PVC main line takes the water from the pump and supplies to 1.5” sub-main PVC pipes network. 20 mm LDPE lateral pipes are connected to the sub-main line and  run along the tree. Two 100Lt/Hr, 3600  spray jets are fitted on opposing sides of the tree.
• Each tree has two 100Ltr/Hr, 3600 spray jets on two sides of the tree. They supply approximately 180Ltrs/Hr to each tree. As the recommended water per tree per day is 65Ltrs, we pump water for 30 minutes per tree.
• Manually operated gate valves control the flow directions. These will be upgraded to power operated solenoid switches with central control.