Sources of Water | Water Supply Engineering

The significant sources of water for supply and consumption are spread among different natural resources. Water is directly or indirectly taken from these sources based on their availability. Water is available through rain, surface sources, sub-surface sources, and water reclamation. 

The overflow plughole on the Ladybower reservoir in full flow. Peak District, England.

In this article, we will outline the features of all the major sources of water and their significance in water supply engineering. 

1. Rainwater

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Rainwater can be a valuable source of water for households and communities, especially in areas where access to clean water is limited. Using a simple arrangement, rainwater can be collected from rooftops, or from prepared catchment directly and stored in a small underground tank or cistern. This helps to meet small individual supplies. 

Rainwater Harvesting

Collecting and using rainwater can help reduce reliance on expensive and energy-intensive water treatment processes, and also help conserve local water resources. However, it is important to ensure that appropriate collection and storage practices are followed to maintain the quality and safety of the harvested rainwater.

2. Surface Water

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Surface sources of water are sources of water available at the ground surface or the ones available as runoff. Surface water is directly used by locals or considered a major source of water supply. The major surface water sources are lakes, seas, rivers, and storage reservoirs.

Based on the type of surface water source, different schemes of collection can be employed.

1. Water from Rivers by Continuous Draft

In this scheme, the water is collected directly from the river, without any diversion work as shown in the figure below.

Water Intake Structure
Image Credits: Xylem

2. Water from Rivers by Diversion Works

In this method, diversion works are constructed across a perennial river. This arrangement diverts the water to a canal which leads water to the site of water purification works as shown in the figure below.

Sources of Water-Diversion Ponds

3. Water from Reservoir Storage

Here, a dam is constructed across the river and water is stored in the reservoir. This arrangement is employed in sites where the water supply is not ensured throughout the year. 

4. Water from Direct Intake from Natural Lakes

This scheme collects water through direct intakes from natural lakes which receive surface run-off from the adjoining catchment.

3. Sub-Surface Sources of Water

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Subsurface sources of water are underground water sources that are used as a water supply system. These are mostly used for water supply by employing certain construction technologies to extract water from their main source i.e. groundwater. 

Infiltration Galleries - Subsurface Sources of Water for Water Supply
Image Credits: Prodyogi

The major sub-surface sources of water are springs, infiltration galleries, infiltration wells, and wells. 

4. Water Obtained by Reclamation

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Water reclamation or water recycling or water reuse is the process of treating wastewater or sewage to remove impurities and make it suitable for various purposes, such as irrigation, industrial processes, or even drinking. 

Reclaimed water is an important resource for areas facing water scarcity, as it can help reduce the strain on natural water sources and provide a reliable and sustainable source of water. However, it is important to ensure that appropriate treatment and monitoring measures are in place to ensure the safety and quality of the reclaimed water.

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