Irrigation & Water Conservation Methods | Multi Skill Foundation - Grade 10 PDF Download

 Page 1


 
 
               
 
 
    
 
 
SESSION 2: IRRIGATION & WATER CONSERVATION 
METHODS 
 
Water is an important aspect of human life. Proper planning is essential for 
conservation of rain water.  
Every year we store the rain water and prepare plans for water supply; but this 
planning falls short because of delayed monsoon. Then the struggle for water 
starts. Controlled usage of water is necessary to fulfill the needs of a growing 
population.  
In this chapter, we are going to learn about water conservation and irrigation 
methods.  
 
Objectives  
· Understanding the need and methods of water conservation. 
· Study of different irrigation  
 
Water Conservation 
The need of water-conservation: - 
Freshwater contributes to only 2% of the total water on the earth.  Groundwater 
contributes to 11% of total freshwater. 
Ground water is a very scarce and a valuable natural resource. Due to 
uncontrolled usage of water, the amount of ground water is gradually decreasing. 
Rain water harvesting is essential to improve the ground water level. 
 
What is rain water harvesting? 
Rain water harvesting is the method for conservation or storage of rain water. 
Simply put, it means collecting the rain water from the roof tops of homes, 
storing it and then using it later after purification.  
 
Urban Areas Rural Areas 
Rooftop runoff water collection 
Recharge pits 
Recharge trench 
Tube wells 
Recharge wells 
 
 
Gully plug 
Level-line dam/Contour Bund 
Gabion Structure 
Percolation tanks 
Check dams/Drain Dams 
Recharge shafts/trenches 
Dug well recharge 
Ground water dams/Subsurface 
dams 
 
In rural areas, the main technique is surface spreading (let rain water soak over 
maximum area) since large open surfaces of land are available for soaking. 
Following methods can be used to avoid flow away from roofs, slopes, rivers, 
rivulets, and drains: 
Gully plugs: - 
Ground water enrichment in rural areas:- 
Page 2


 
 
               
 
 
    
 
 
SESSION 2: IRRIGATION & WATER CONSERVATION 
METHODS 
 
Water is an important aspect of human life. Proper planning is essential for 
conservation of rain water.  
Every year we store the rain water and prepare plans for water supply; but this 
planning falls short because of delayed monsoon. Then the struggle for water 
starts. Controlled usage of water is necessary to fulfill the needs of a growing 
population.  
In this chapter, we are going to learn about water conservation and irrigation 
methods.  
 
Objectives  
· Understanding the need and methods of water conservation. 
· Study of different irrigation  
 
Water Conservation 
The need of water-conservation: - 
Freshwater contributes to only 2% of the total water on the earth.  Groundwater 
contributes to 11% of total freshwater. 
Ground water is a very scarce and a valuable natural resource. Due to 
uncontrolled usage of water, the amount of ground water is gradually decreasing. 
Rain water harvesting is essential to improve the ground water level. 
 
What is rain water harvesting? 
Rain water harvesting is the method for conservation or storage of rain water. 
Simply put, it means collecting the rain water from the roof tops of homes, 
storing it and then using it later after purification.  
 
Urban Areas Rural Areas 
Rooftop runoff water collection 
Recharge pits 
Recharge trench 
Tube wells 
Recharge wells 
 
 
Gully plug 
Level-line dam/Contour Bund 
Gabion Structure 
Percolation tanks 
Check dams/Drain Dams 
Recharge shafts/trenches 
Dug well recharge 
Ground water dams/Subsurface 
dams 
 
In rural areas, the main technique is surface spreading (let rain water soak over 
maximum area) since large open surfaces of land are available for soaking. 
Following methods can be used to avoid flow away from roofs, slopes, rivers, 
rivulets, and drains: 
Gully plugs: - 
Ground water enrichment in rural areas:- 
 
 
               
 
 
    
 
These small dams are built using locally available stones, clay, nearby bushes 
across small gullies and streams running down the hill slopes and are used to 
accumulate and soak the water from streams and rills flowing down the hillside 
slopes. This helps in improving the moisture level and fertility of the soil. Such 
gully plugs can be built where there is a local break in slope and the flow of water 
is blocked or slows down.  
The system of bunds connecting places at same elevation (level-line dam) is very 
useful in retaining soil moisture in the watershed for long time. Useful in low 
rainfall area 
 
Percolation tank: - 
It is suitable for highly permeable land. In this water conservation method 
surface water runoff is made to percolate & recharge the ground water storage. 
We can provide this storage water to nearby wells. The objective of these kind of 
tanks is to facilitate water absorption and recharge levels of ground water.  
 
  
 
With the help of recharge pits we can store rain water. We can use this water 
conservation method in area where surface 
rocks are permeable.  
The recharge pits are constructed 1-2 meters 
wide and 2-3 meter deep.  
The pits are then filled with boulders (5 to 20 
cms), gravel and coarse sand, so that the silt 
content that will come with runoff water will 
be easily removed.                                                            
                                                                          
Fig 10 - Recharge pits 
For the buildings with smaller roof areas, the 
pit can be filled with pieces of broken bricks 
and gravel. To maintain the water recharge rate, it is essential to periodically 
clean up the silt and other waste materials from the top layer of sand.  
  
 
Rain water harvesting is a process of storage the water from rain fall and then 
using it later at appropriate time. Simply put, it means collecting the rain water 
from the roof tops of homes, storing it and then using it later after purification.  
 
Why rain water harvesting? 
Today, scarcity of quality water has become a major problem. Available sources 
drinking water are depleting. Considering this, it is essential to enrich the 
available natural sources of water. The rain water is left unused and lost as run 
off. Therefore, rain water harvesting is necessary. 
 
Benefits of rain water harvesting: 
· Rain water harvesting can become a supplement for other sources of water 
supply. (e.g. groundwater or municipal water) 
· The areas without water supply Rain water harvesting has a ability to build or 
for farming. 
Recharge pits:- 
What is rain water harvesting?