What does CGWB do and what is the Junior Hydrogeologist's role?

The Central Ground Water Board (CGWB) is the national apex agency for scientific assessment, dissemination, and regulation of India's groundwater resources. A Junior Hydrogeologist conducts hydrogeological surveys, drills and tests exploratory wells, analyzes groundwater quality and quantity data, prepares ground water resource assessments for districts, and issues NOCs for groundwater extraction through Central Ground Water Authority (CGWA) under the Environment Protection Act 1986. CGWB also monitors groundwater levels quarterly and assesses the status of over-exploited, critical, and semi-critical groundwater assessment units across India.

What geology topics are tested in the CGWB hydrogeologist exam?

The exam covers general geology (mineralogy, petrology, stratigraphy of Indian geology including Gondwana formations, Deccan Traps, and Indo-Gangetic alluvial plains), structural geology (faults, folds, lineaments and their role in groundwater occurrence), geomorphology and landforms relevant to groundwater, remote sensing for hydrogeological mapping, and engineering geology. For hydrogeology specifically: Darcy's law, aquifer types (confined, unconfined, leaky, perched), pump test analysis (Theis, Cooper-Jacob methods), water quality assessment (BIS groundwater quality standards), and contaminant transport in aquifers.

How does CGWB enforce groundwater regulations under environmental law?

CGWB enforces groundwater regulation through the Central Ground Water Authority (CGWA), constituted under the Environment Protection Act 1986. Industries and projects abstracting groundwater above 10 cubic meters per hour require NOC from CGWA. EIA Notification 2006 mandates hydrogeological assessment for projects in water-scarce areas. CGWB also advises on groundwater development in areas of arsenic, fluoride, and heavy metal contamination — particularly relevant to East India arsenic belt (Bengal, Bihar, Jharkhand), Rajasthan fluoride belt, and industrial groundwater contamination zones.

What quantitative hydrogeology is important for the CGWB exam?

Important quantitative topics include Darcy's Law applications, transmissivity and storativity calculations from pump test data, Theis equation and Cooper-Jacob straight-line method for confined aquifers, Boulton method for unconfined aquifers, determination of specific yield, water table fluctuation method for recharge estimation, chemical equilibrium calculations for groundwater quality, preparation of Piper diagrams and Stiff diagrams for hydrochemical facies analysis, and basic hydrogeological cross-section construction from borehole data.

What is the groundwater assessment methodology used by CGWB?

CGWB uses the Ground Water Resource Estimation Methodology (GEC 2015) developed by the Ground Water Estimation Committee to assess groundwater availability at the assessment unit (block/taluka/mandal) level. The methodology involves estimating annual replenishable groundwater resource from rainfall, irrigation return flow, and other recharge sources, deducting natural discharge, and calculating net groundwater availability for future use. Units are then categorized as Over-Exploited (>100% extraction), Critical (90-100%), Semi-Critical (70-90%), or Safe (<70%). This framework is tested in detail in CGWB exams.

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CGWB Junior Hydrogeologist Preparation Guide

Central Ground Water Board, Ministry of Jal Shakti

Your Complete Preparation Guide for CGWB Junior Hydrogeologist 2027 — strategy, study plan, tips & more.

DifficultyHard

Total Marks100

Duration120 min

Start Practising Now →Free Mock Tests

Exam Overview

Mode

Online CBT followed by Interview

Frequency

As per vacancy notification

Next Exam Date

2026-10-25

EEligibility Criteria

M.Sc. in Geology/Applied Geology/Hydrogeology with minimum 55% marks. Candidates with knowledge of hydrogeological investigation techniques preferred. Age limit 30 years with standard government relaxations.

ANumber of Attempts

No specified limit; age-bar applies

Study Plan by Subject

Geology

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Hydrogeology

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

General Studies

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Mathematics & Statistics

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Expert Preparation Tips

Master pump test analysis methods — Theis, Cooper-Jacob, and Boulton methods — with numerical practice, as these are core hydrogeology skills tested by CGWB.

Study Indian geology thoroughly: Gondwana coal sequences, Deccan Traps hard rock aquifers, Indo-Gangetic alluvial aquifer system, and hard rock fractured aquifers of peninsular India.

Learn the GEC 2015 groundwater assessment methodology and India's categorization of over-exploited blocks, as CGWB exam directly tests this operational framework.

Review the Environment Protection Act 1986 provisions related to CGWA, groundwater abstraction NOC requirements, and water quality standards for drinking water under BIS standards.

Exam Pattern at a Glance

Section	Questions	Marks	Duration (est.)
Geology	25	25	30 min
Hydrogeology	25	25	30 min
General Studies	25	25	30 min
Mathematics & Statistics	25	25	30 min
Total	100	100	120 min

Important Dates

Registration Opens

2026-08-15

Next Exam Date

2026-10-25

Conducted By

Central Ground Water Board, Ministry of Jal Shakti

Frequently Asked Questions

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