Flood is a natural even which has always been an integral part of geological history of earth. It occurs along rivers, streams and lacks. Most of the hydraulic are designed on flood record. Small hydraulic structures are based on a minimum of 25 years flood records e.g all structure constructed in the canal, soil conservation practices etc. Large irrigation projects are based on 100

The public health engineering sector is responsible for the Collection of water, purification, transmission and distribution of water. A Public Health Engineer has to perform his job by calculating design flow, design population, design area and population density. Quality of the collected water is checked by physical and chemical tests on water and if the quantity is not

Population is one of the most important factors for design of the water systems, so it should be estimated, so as to know the increasing demand and ensure continuous supply to them. Population data is obtained by previous records and the rate of increase is found out and this used for further analysis, which may be by using the methods described below

Domestic uses of water include the consumption of water for drinking, washing, cooking, toilets, livestock etc. the domestic average use per capita per day is 50 – 90 gallons (70 – 380 liters per capita per day).

Flexible pavements are those pavements which reflect the deformation of subgrade and the subsequent layers to the surface. Flexible, usually asphalt, is laid with no reinforcement or with a specialized fabric reinforcement that permits limited flow or re positioning of the roadbed under ground changes. The design of flexible pavement is based on load