TY - GEN ED - Helvetas Sri Lanka TI - Gravity water supply systems : design and construction SN - 9558699071 PY - 2005/// CY - Colombo PB - Third Water Supply & Sanitation Project KW - WATER SUPPLY SYSTEMS-Design and Construction N1 - Hydro logic cycle and fresh water occurrence; Water sources, quality and quantity; Hydraulics; Pipeline construction; Break pressure tanks, distribution chambers and valve chambers ER -