Sources of water and Engineering assignment help

The sources of water supply may be divided into following classes according to the general source and the method of collection:

Surface Water

(a) Natural quiescent water in lakes and ponds

(b) Flowing water as in rivers and streams etc.

(c) Artificial quiescent water as in impounding reservoirs

(d) Sea Water

Ground Water

(a) Water from springs

(b) Water from shallow wells

(c) Water from deep and artesian wells

(d) Water from horizontal galleries

Surface Water Sources

Natural Quiescent Water as in Lakes and Ponds

The quality of water of natural ponds and lakes are more uniform in quality than any other flowing sources of water and does not need much purification. If the catchments of the lakes/ponds are protected and non-erodible, it normally does not get in touch with surface contamination and thus its water may be safely supplied just after disinfection. Larger and older lakes permit self purification of water due to sedimentation of suspended matter and removal of bacteria to a greater extent as compared to smaller and newer lakes. However, in still water of lakes and ponds the algae, weed and other vegetation grow freely, causing bad smell, taste and colour etc. Due to low catchment area of the lake basin, quantity of available water is normally less, hence these are not considered as principal source of water supply except in hilly and small towns, where there is o other source of water.

 Ground Water Sources

Water precipitated upon the surface of the earth is disposed off in three ways – by evaporation, by surface flow and by percolation.

Percolating water that passes beyond vegetation passes on downward in obedience to the law of gravitation until it reaches an impervious layer of some kind. The accumulation of water which exists in the ground is called ground water and its top is known as ground water level or ground water table. The volume of water stored in any soil/rock strata depends mainly on porosity (i.e. maximum water storage capacity) and permeability (which determines the ability to transmit water through itself) of rock/soil strata.

To obtain large quantity of water economically, it is necessary that water bearing strata be of open and porous character. The sand and gravel deposits possess high porosity as well as permeability, hence they are considered as most favorable formations for furnishing large quantity of water for public water supply schemes

The rate of water movement in the strata depends upon two factors; i.e. (i) permeability of the soil strata, and (ii) driving force for the hydraulic gradient, usually expressed as the ratio between the difference in elevation of the two points on the water table in the direction of flow, and the distance between them. Students who are interested in taking up this subject can get online engineering assignment help from the experts of this field so that they can get the basic knowledge regarding this subject. It is mandatory for each and every student to opt for online environmental engineering help such that they can excel in this field. These websites not only provide online assignment help but also provides them with the online experts support.