The World Association for the Development of Philately (WADP) and the Universal Postal Union (UPU) jointly conceived and developed the WADP Numbering System - WNS, which was launched on 1 January 2002.

LK001.11

Country / Post Sri Lanka
Date of Issue 18 January 2011
Primary theme Engineering (Dams)
Subject 125th Anniversary of Labugama Resevoir & Water Purification Plant
Width 60.0 mm
Height 30.0 mm
Denomination 5.00 LKR
Number in set 1
Layout/Format sheet of 50
Perforations 14 by 13.5
Stamp issuing authority Department of Posts
Printer Department of Government Printing, Sri Lanka