Multi-purpose River Water Projects: Exam-ready Q&A

Medium (Application & Explanation)

Answer:

These are large projects that use river water for many purposes at the same time.
Main purposes are irrigation, drinking water, hydropower, and flood control.
They may also support navigation, fish breeding, and recreation.
The main structures are dams, reservoirs, canals, and powerhouses.
Example projects are Bhakra Nangal, Hirakud, Tehri, and Sardar Sarovar.
Such projects store water, control flow, and distribute water to many users.
They reduce monsoon dependence and help regional development.

Answer:

IWRM means managing water resources in a holistic and coordinated way.
It links agriculture, power, industry, and domestic supply.
It focuses on sustainability so future generations have enough water.
It ensures equitable distribution among regions and communities.
It combines traditional methods with modern systems for better use.
Example: Linking large dams with local rainwater harvesting for irrigation.
In India, irrigation canals also feed hydropower stations to save water.

Answer:

The Harappan Civilisation built advanced drainage and storage like the Great Bath.
Tank irrigation in South India stored rainwater in big tanks for fields.
Stepwells (baolis) in Gujarat and Rajasthan stored water and cooled spaces.
Medieval rulers built canals, like Firuz Shah Tughlaq’s Yamuna–Hisar canal.
These systems used local knowledge and community care for maintenance.
They prove a long tradition of collective management and water sharing.
They inspire IWRM by valuing local systems with modern networks.

Answer:

Gravity dams use heavy concrete/stone to resist water pressure. Example: Bhakra Nangal.
Arch dams are curved and push pressure to canyon walls. Example: Idukki.
Earthen dams use compacted earth and are cheaper. Example: Hirakud.
Embankment dams mix earth and rock. Example: Tehri.
Gravity dams suit narrow valleys with strong foundations.
Arch dams suit deep gorges with strong rock sides.
Earthen/embankment dams suit wide valleys with good soil availability.

Answer:

Bhakra Nangal (Satluj): Irrigation, hydropower, flood control in Punjab–Haryana–Rajasthan.
Hirakud (Mahanadi): Irrigation, power, flood control in Odisha–Chhattisgarh.
Damodar Valley: Irrigation, power, flood control, industrial water in Jharkhand–West Bengal.
Sardar Sarovar (Narmada): Drinking water, irrigation, power in Gujarat–MP–Maharashtra–Rajasthan.
Tehri (Bhagirathi): Drinking water, irrigation, power in Uttarakhand.
Indira Gandhi Canal: Irrigation and drinking water in Rajasthan.
These projects support farmers, cities, industry, and regional growth.

Answer:

First, map water demand for farms, homes, and small industries.
Use the dam reservoir for a canal schedule with fair water turns.
Add local rainwater harvesting: farm ponds, check dams, and rooftop tanks.
Promote micro-irrigation like drip and sprinkler to save water.
Connect hydropower to village pumps and cold storage for agriculture.
Form water user groups to ensure equitable sharing and reduce conflicts.
Monitor groundwater recharge by linking canals to percolation pits.

Answer:

Benefits: Irrigation, drinking water, and renewable power for the region.
Risks: Displacement of people, loss of forests, and biodiversity decline.
Social costs: Livelihood loss, culture disruption, and delayed rehab.
Environmental costs: Flow changes, fish migration issues, waterlogging and salinity.
Safeguards: Strong R&R (rehabilitation and resettlement) with land-for-land and services.
Design environmental flows, fish ladders, and catchment treatment.
Create benefit-sharing: local jobs, compensation, and revenue for host communities.

Answer:

Set up a river basin authority with both states and central observers.
Use scientific data: rainfall, inflows, and seasonal needs for both sides.
Fix allocations by season with minimum ecological flow to the river.
Prioritise drinking water, then irrigation, then power in dry months.
Promote efficiency: micro-irrigation, lining canals, and crop planning.
Add drought clauses and surplus-sharing rules for wet years.
Use real-time monitoring and dispute resolution with time-bound decisions.

Answer:

Ancient tanks were local, low-cost, and community-managed.
Modern multipurpose projects are large, centralized, and capital-heavy.
Tanks work well for local farms and groundwater recharge.
Dams give assured supply, power, and flood control across regions.
Hybrid model: Use the dam for back-up supply, and revive tanks for daily use.
Link canals to tank chains; add check dams and percolation ponds.
Manage through local committees under an IWRM plan for equity and sustainability.

Answer:

Count benefits: irrigation area, drinking water, and hydropower capacity.
Count costs: displacement, forest loss, and ecology impacts.
Example: Sardar Sarovar brought water but caused rehabilitation struggles.
Example: Hirakud controlled floods but raised waterlogging concerns.
Ensure strong R&R, ecological flows, and soil salinity control plans.
Add alternatives: rainwater harvesting, demand management, and efficiency.
Approve only if net public good with equity and long-term sustainability is clear.