Catchment area

Catchment Area development

IntroductionWater conservation methodologies is not just a recent technique but it is used from very past.

In India , right from 2500 years right from Satvahan era,various methods of water conservation are practised

Many places in south India and certain parts of Western ghats,various tanks are carved for water collection and storage

Many cities of the world are build near any river source.Human civilization is settled near water source from thousands of years

With growth of population and limited water resources,there is a need to conserve water.This slide describes about catchment areas

Objective of this presentation

To collect information on catchment areas

To know about small dam structures

To know about benefits of area coming under catchment

Catchment Area

• Land is not leveled everywhere

• The topography consists of plain land and mountains

• Rain water from mountain top of high land flows on slopes

• This flowing water accumulates on a plain area known as catchment

Size of Catchment Area It can be small or big

It can be of 10 to 20 hectares or size of river basin

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How to select a Catchment

• Catchment area consists of a river basin or a source stream

• It can span huge area

• The size should not be small or too big

• Small catchment area is not benefitial for storage

• It should be selected such that minimum 5 villages are benefitted

Objective of Catchment Area Development

• To make usage of land which is not in use

• To stop soil erosion

• To store rainwater which is wasted

• To bring maximum amount of area under irrigation

• To promote plantation over barren lands

• To make available drinking water for all

What can be done under Catchment Development ?

• Developing Contours in an level

• Developing a small dam

• Constructing small lake

• Constructing a Bund

• Leveling of land under catchment area

• Plantation of trees surrounding the area

Solutions through Catchment Development

• Crop pattern according to category of land

• Intercropping

• Multiple Cropping

• Plantation on slopes

• Controlling water flow and floods

• Increased moisture of soil

Effects of Soil erosions

• Erosions occurring in steps

• Formation of stream

• Landslides

• Change in course of river flow

• Expanding of river banks

• Excavation of land due to water flow

Things to consider in Catchment

• Natural resources

• Wind, sunlight and vegetation types

• Local and social problems

• Topography of the area

Beneficiaries of catchment area

• Agriculture as well as barren lands

• Villagers

• Domestic animals and cattles

• Forested areas

• Areas under plantation

Causes of Soil Erosion

• Steep slopes

• Landslides

• Floods

• Uncontrolled Flow of water

Due to erosion, nutrients in soil is also lost and the permeability of soil is also lost

Types of Structures

• Vasant bandhara type of dams

• Small check dams

• Gabian type check dams

• Lake

• Cemented bunding small dam

• Nala Bunding

• Contours marking

Images given in further slides

Contours

Vasant bandhara

• These types of small dams were built during famine of 1972

• Useful for small streams flowing in village

• Foundation of hardly 2 feet or digging it till a firm rock below ground

• Hardly 1.5 to 2 feet in height from foundation base

• Image shown in next slide

• Vasant Bandhara

Check Dam on Slope

Nala Bunding

Water can be stored in small amounts by the nala bunding method

Useful for small villages where there is a small stream

Lake construction

Useful for drought Prone Areas.

Usually Constructed before rainy season

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Small Cemented dam