Water Resources · Class 10 Geography: quick revision, 70 bites

Why Water Is Renewable

One sentence answers the exercise.

Takeaway. The cycle is the reason, so name the cycle.

Three-Fourths, and a Small Proportion

Plenty of water, very little usable.

Water covers three-quarters of the planet’s surface, and only a **very small share** of that is **fresh water we can actually use**.

Takeaway. Abundance overall is not availability where people live.

Scarcity Is Not Low Rainfall

The picture in our heads is wrong.

We picture deserts and long walks with **matkas**. Availability does vary with **seasonal and annual precipitation** — but that is not the main cause.

Takeaway. All three named causes are human, not climatic.

Ample Water, Still Scarce

Cities prove the point.

Can a region have ample water resources and still face scarcity? **Many of our cities are such examples.**

Takeaway. Manufactured scarcity, not inherited scarcity.

Irrigated Agriculture Leads

The biggest user of all.

To raise food-grain production, water is drawn down too hard to widen the irrigated area for **farming in the dry season**. **Nothing consumes more water than irrigated farming.**

Takeaway. More people means more food, and more food means more water.

Wells, Tube-Wells and Food Security

A private solution with a public cost.

Takeaway. What raises one farm's yield can lower a district's water.

Industrialisation and Urbanisation

Two forces that arrived together.

Takeaway. Post-independence growth brought opportunity and pressure together.

Scarcity of Quality

Enough water, and none to drink.

Water may be **sufficient to meet the needs of the people** and still be unusable, because much of it is **polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers**, making it **hazardous for human use**.

Takeaway. Scarcity is about usable water, not about volume.

Which Region Suffers Scarcity?

The exercise, settled.

Takeaway. High rainfall does not guarantee enough usable water; demand and quality count too.

Jal Jeevan Mission

A promise with a number in it.

Takeaway. A measured service level, not just a connection.

Atal Bhujal Yojana

Four numbers and seven states.

Takeaway. Targeted at the places already over-exploited, critical or semi-critical.

Changing Behaviour, Not Just Pipes

The unusual aim.

Much of what Atal Jal is after is a **change of habit** in the community itself — moving people from thinking about **how much they can use** to thinking about **how much they can save**, and managing water intelligently.

Takeaway. Conservation is treated as something people do, not something built.

Why Conserve Water

Four reasons, worth memorising.

Takeaway. Health, food, livelihood, ecosystems.

What Cities Did to Water

One exercise statement to correct.

The correction: they have **added to water and energy requirements** and **further aggravated the problem**, with fragile resources over-exploited and depleted in several cities.

Takeaway. Cities aggravated the problem; they did not solve it.

What a Dam Is

The word means the water, not the wall.

Takeaway. Name the barrier and the reservoir it creates.

The Spillway

A dam is built to let water through.

Most dams have a section called a **spillway or weir** over or through which water is **intended** to flow, either **intermittently or continuously**.

Takeaway. Controlled release is part of the design.

How Dams Are Classified

Three ways to sort a dam.

Takeaway. Structure, purpose, height — three bases, not one.

What Dams Are Built For Today

One job became seven.

Traditionally they were built only to impound water for **irrigating agricultural fields**.

Takeaway. Seven uses, and the list is examinable in full.

Why 'Multi-Purpose'

One word carries the term.

Takeaway. Integration, not scale, is the definition.

Bhakra-Nangal and Hirakud

The pair most often asked for.

Takeaway. Learn each with its basin, and do not swap the pairs.

Temples of Modern India

The phrase, and the reason behind it.

**Jawaharlal Nehru** proclaimed the dams the **'temples of modern India'** — because they would **knit farming and the village economy together with fast industrial growth and an expanding urban economy**.

Takeaway. One structure expected to join the village to the factory.

The Vehicle of Development

Why they carried such hope.

Launched **after Independence** with an **integrated water resources management** approach, multi-purpose projects were thought of as **what would carry the country forward into development and progress**, getting past the burden left by **colonial rule**.

Takeaway. They were a political promise as much as an engineering one.

Sardar Sarovar

Four states, and a page of figures.

Takeaway. One of the largest water resource projects of India.

Drought-Prone Command Areas

Aimed where the rain is not.

About **75 per cent** of the Sardar Sarovar command area in **Gujarat** is drought prone, while the **entire** command area in **Rajasthan** is.

Takeaway. The project's case rests on where the water goes.

The Krishna-Godavari Dispute

Rivers ignore state boundaries.

**Karnataka** and **Andhra Pradesh** object to **Maharashtra** diverting more water at **Koyna** for a multipurpose project, since it would reduce **downstream flow** in their states.

Takeaway. A project in one state is a loss in another.

Hydraulic Structures in Ancient India

Older than the British, older than Delhi.

Takeaway. Modern India continued a tradition rather than beginning one.

Pradhan Mantri Krishi Sinchayee Yojana

Two slogans worth knowing.

Takeaway. The two Hindi phrases are the ones examiners quote.

From the Basin to the Field

The unit has shrunk.

A multi-purpose project plans a whole **river basin**. The Krishi Sinchayee Yojana plans a single **farm** — water on the farm, efficiency on the farm, a crop per drop.

Takeaway. Watch the scale change across this chapter.

Under Great Scrutiny

The chapter turns on itself.

Lately, multi-purpose projects and big dams have met **hard questioning and organised opposition, on several different grounds**.

Takeaway. The case against is built out of the case for.

What Damming Does to Sediment

Too much above, too little below.

The result is **rockier stream beds** and **poorer habitats** for the river's aquatic life.

Takeaway. One barrier produces two opposite sediment problems.

Rivers Fragmented

A wall across a journey.

A dam **cuts a river into pieces**, and **water creatures that need to travel — above all to spawn — can no longer get through**.

Takeaway. A continuous river becomes separated stretches.

Submerged Vegetation and Soil

What is drowned does not vanish.

Reservoirs created on the **floodplains drown the plants and soil already there**, which then **rot away over the years**.

Takeaway. A slow process that begins when the reservoir fills.

Flood Plains Deprived of Silt

Free fertiliser, stopped.

Sedimentation meant the flood plains went **without their silt, a fertiliser nature supplies free**, which added further to the problem of **land degradation**.

Takeaway. A loss downstream caused by a gain upstream.

Ironically, Floods

The word the chapter itself uses.

**Dams put up to prevent floods have caused them** — the reservoir silts up and the water has nowhere to go.

Takeaway. The clearest single point in this section.

The Mechanism Behind the Irony

Why a full reservoir is a dangerous one.

Takeaway. Capacity falls every year the dam stands.

Life, Property and Soil

What those floods left behind.

The floods **destroyed lives and property**, and stripped away **soil on a large scale** besides.

Takeaway. Damage to people and to land in the same event.

Earthquakes, Disease and Pollution

Three effects that are easy to forget.

Takeaway. Learn the three together; they are usually asked together.

From Assured Water to Salt

A problem produced by success.

Takeaway. When water is assured, it pays to grow the thirsty crop.

Advantage Against Disadvantage

Pair them, do not list them.

Takeaway. A paired answer reads far better than two loose lists.

Damming and Sediment Flow

One exercise statement to rewrite.

The correction: it **does** affect both, so that **sediment moves badly** and **far too much of it settles on the reservoir floor**.

Takeaway. Reverse the negative and add the two consequences.

Displacement and Loss of Livelihood

The statement that is not an argument in favour.

An exercise asks which statement is **not** an argument in favour of multi-purpose projects. The answer is that they **lead to large scale displacements and loss of livelihood**.

Takeaway. A disadvantage the exercise supplies, and you may cite it.

A Plan for the Five-Mark Question

How to structure the comparison answer.

Takeaway. Purposes, river, land, floods, health and farming.

Five Dams Live Only on the Map

Reading the chapter is not enough.

The chapter's text names only **three** of the eight prescribed dams — **Bhakra Nangal**, **Hirakud** and **Sardar Sarovar**.

Takeaway. Study the map as a separate piece of work.

Learn the Pair, Not the Dot

Find the river, and the dam follows.

On a blank outline the **rivers are drawn for you**; the dams are not. So remember each dam **with its river** rather than trying to recall a position.

Takeaway. The river is the locator.

Eight Dams, Eight Rivers

The whole list in one table.

Takeaway. This table is the whole map syllabus for the chapter.

Working Down the Map

They run north to south.

Takeaway. Place the first and work downward.

Salal, on the Chenab

The northernmost of the eight.

**Salal** stands on the **Chenab** in **Jammu and Kashmir**, at the very top of the map, above Bhakra Nangal.

Takeaway. Top of the map, on the Chenab.

Bhakra Nangal, on the Satluj

The one the text does describe.

**Bhakra Nangal** stands on the **Satluj** on the Punjab-Himachal border. This is the **Sutluj-Beas basin** of the chapter's text, where water serves **hydel power production and irrigation**.

Takeaway. Map answer and text answer in one place.

Tehri

In the hills of Uttarakhand.

**Tehri** lies in the **upper Ganga basin** in **Uttarakhand**, east of Bhakra Nangal on the map.

Takeaway. One place name, two chapters.

Rana Pratap Sagar and Its Neighbours

Three dams, one river.

Takeaway. Use the neighbours to find it, then label the right one.

Sardar Sarovar, on the Narmada

The four-state project.

**Sardar Sarovar** stands on the **Narmada** in **Gujarat**, just above the Tapi on the map. It covers **Maharashtra, Madhya Pradesh, Gujarat and Rajasthan**.

Takeaway. The west-coast dam, and the one with the most figures attached.

Hirakud, on the Mahanadi

The eastern one.

**Hirakud** stands on the **Mahanadi** in **Odisha**, inland from the Bay of Bengal — the project that integrates **conservation of water with flood control**.

Takeaway. East, not south.

Nagarjuna Sagar and Tungabhadra

The two southern dams.

Takeaway. Both peninsular, both map-only.

The Landmark Dams

More dots than you need.

**Koyna** is the site of the diversion in the **Krishna-Godavari dispute**.

Takeaway. Not asked for, but they help you place what is.

The Map Question and Its Alternative

Know who the written alternative is for.

Takeaway. Everyone else answers on the map, so practise placing all eight.

Hirakud or Hirakund?

One letter, no marks lost.

The syllabus list writes **Hirakund** and **Nagarjun Sagar**. Your textbook map writes **Hirakud** and **Nagarjuna Sagar**.

Takeaway. A spelling difference, not a difference in the answer.

Harvesting as an Alternative

Why the old ways were reconsidered.

Given the disadvantages of multi-purpose projects and the **rising resistance** against them, water harvesting was thought a **viable alternative, both socio-economically and environmentally**.

Takeaway. The scale shrinks again, and deliberately.

Built to Suit the Place

No single method, because no single India.

People understood **their rainfall patterns and their soils thoroughly**, and harvested **rainwater, groundwater, river water and flood water** in keeping with **local ecological conditions and their water needs**.

Takeaway. Each region built what its own rain and soil allowed.

The Traditional Methods

Four regions, four answers.

Takeaway. Learn the method with its region; the pairing is the answer.

Khadins and Johads

The field becomes the tank.

Takeaway. Here the store is the field itself.

Tankas of Bikaner, Phalodi and Barmer

Three districts, one habit.

Nearly every house once kept **drinking water in an underground tank — a tanka** — dug **within the house itself or out in the courtyard**.

Takeaway. Three district names worth remembering together.

How a Tanka Fills

Six steps, and one of them is counter-intuitive.

Takeaway. This sequence is what an exercise question asks you to discuss.

Why Skip the First Shower

The first rain is thrown away on purpose.

The design sacrifices the first rain to make everything after it drinkable — which is why the water keeps until the next year.

Takeaway. A deliberate loss for a year of clean water.

Palar Pani

The local name, and the local verdict.

Takeaway. A store of water that also cooled the house.

Declining, Not Gaining

The exercise statement to correct.

Some houses still maintain their tankas, since they **do not like the taste of tap water**.

Takeaway. Convenience arrived and the habit faded.

Tamil Nadu Makes It Compulsory

The first state to require it.

**Tamil Nadu** is the **first state in India** to make a rooftop rainwater harvesting structure **obligatory for every house in the State**, with **legal provisions to punish the defaulters**.

Takeaway. Not encouraged — required, and enforced.

Shillong

The wettest place on earth, and a city short of water.

**Cherapunjee and Mawsynram**, just **55 km** away, receive the **highest rainfall in the world** — yet **Shillong faces acute shortage of water**.

Takeaway. Proof that rainfall and supply are different things.

Gendathur, Mysuru

A village rich in rainwater.

Takeaway. A remote village that solved its own supply.

Recharge, Not Only Storage

The roof refills the aquifer.

The two illustrated forms are recharge through a **hand pump** and through an **abandoned dugwell**.

Takeaway. Modern systems put water back into the ground.

The Meghalaya System

Drip irrigation, made of bamboo.

Takeaway. Precision irrigation, two centuries before the word existed.