Surface Sources of Water - Water Supply Engineering

Surface sources of water are sources of water available at the ground surface. Surface water is directly used by locals or considered a major source of water supply.

When surface water is employed for water supply and distribution, they are taken through various testing and treatment so that they are used safely by the consumers.  

Lakes - Surface Source of Water

Factors Affecting Sources of Water for Water Supply System

The source of water is selected based on the:

• Quantity of water available
• Quality of the water
• Economy 
• Transportation cost

Types of Surface Sources of Water

Surface water is the water bodies seen on the surface of the earth. Usually, these water bodies have suspended solids in them. They usually give us an ugly appearance, from a water supply design point of view.

The surface water sources include:

1. Lakes or ponds
2. Sea/Oceans
3. Rivers/Streams
4. Storage reservoir

Surface Sources of Water

1. Lakes or Ponds

Lakes are natural basins that are formed with impervious beds by springs or streams called lakes. When these lakes or ponds are formed in mountains, at higher altitudes, this water can be used without any treatment. 

But when lakes are formed as a result of any construction activities, or in a heavily populated area, those lakes contain impurities, like algae, vegetational matter, organic matter, etc. They cannot be consumed without treatment and they are not available in amble quantity to act as a source of the water supply system.

2. Seas and Oceans

These water sources account for 97 % of the water on the earth. This water is saline and also consists of toxic minerals. They are present in plenty, and to be consumed by the population, it needs costly treatment. 

The treatment of saline water to be used in the water supply system are, desalination, UV treatment, reverse osmosis, etc. It is not used in India but used in Arab countries. 

3. Rivers and Ponds

These are the main source of water for the water supply system. Rivers undergo continuous flow, unlike lakes. They have a minimum velocity of 0.45 m/s and an average velocity of 0.9 m/s. They possess a self-cleansing velocity. 

It possesses fewer impurities compared to other sources, as it is running water.

4. Storage Reservoirs or  Impounding Reservoirs

An impounding or storage reservoir is a basin constructed in the valley of a stream or river for the purpose of holding stream flow so that the stored water may be used when the supply is insufficient. This water is used after purification.

Read More On: Sub-Surface Sources of Water