Low Cost Drainage for Emergencies
Effective drainage is important in emergencies when there is a risk of flooding or there is a risk of poor environmental health conditions developing from standing water, muddy conditions, or erosion. It would not usually be the first priority in the initial stages of an emergency, but should be considered after the immediate water, sanitation and hygiene needs have been met. Sites which have natural slopes and drainage may not require additional work except in localised areas, such as providing cut off drains to prevent water from flowing into latrines or shelters. This Technical Brief provides an overview of the general principles of good drainage design and introduces a range of construction options for simple drainage channels, erosion control and road crossings. It focuses only on surface water drainage and does not cover the disposal of sullage or sewage. It has drawn heavily on early work by UNCHS (Habitat) and by the ILO in the area of labour intensive construction and low cost drainage.