💧Introduction
Water is one of the most dangerous hazards in mining. Sudden inrush of water from old workings, surface sources, aquifers, or heavy rains can cause catastrophic mine inundations. Many of India’s worst mine disasters (e.g., Chasnala 1975) were caused by uncontrolled water hazards. The DGMS (Directorate General of Mines Safety) prescribes strict provisions under the Mines Act, Coal Mines Regulations 2017, Metalliferous Mines Regulations 1961, and DGMS circulars to prevent and control water hazards. Understanding these rules is critical for DGMS exams and for safe mine management.
⚠️ Types of Water Hazards
💡 Prevention & Drainage Systems
📑 DGMS Case Studies (H3)
📝 Quick One-Liners
✍️ Descriptive Model Answer
Q: What are the statutory provisions and preventive measures for water hazards in coal mines?
Answer: Water hazards in mines are regulated under CMR 2017 (Regs. 126–128), which mandate accurate surveys, barrier thickness, pumping arrangements, and preventive boreholes. The main measures are:
🎯 20 MCQs – Water Hazards (DGMS Exam Practice)
Q15.1 The most dangerous source of water hazard in underground coal mines is:
A. Aquifer seepage
B. Old water-logged workings
C. Rainwater inflow
D. Pump failure
E. High humidity
Answer: B.
Solution: Inundations mainly occur from old flooded workings.
Q15.2 Minimum accuracy of survey for detecting old water-logged workings is:
A. 30 m
B. 20 m
C. 15 m
D. 10 m
E. 5 m
Answer: C.
Solution: CMR 2017 requires ≤15 m accuracy.
Q15.3 Sump capacity must be at least:
A. 2 hours inflow
B. 3 hours inflow
C. 4 hours inflow
D. 6 hours inflow
E. 8 hours inflow
Answer: C.
Solution: Regulation 126 requires 4 hours inflow capacity.
Q15.4 Protective barrier thickness between adjacent mines is required under:
A. Reg. 124
B. Reg. 125
C. Reg. 127
D. Reg. 129
E. Reg. 131
Answer: C.
Solution: Reg. 127 covers barrier thickness.
Q15.5 DGMS mandates standby pumps because:
A. Save electricity
B. Handle peak inflow
C. Ensure pumping during breakdown
D. Reduce manpower
E. None
Answer: C.
Solution: Standby ensures safety if main pump fails.
Q15.6 In opencast mines, primary drainage system is:
A. Forepoling
B. Garland drains and sumps
C. Shaft pumps
D. Borehole drilling
E. None
Answer: B.
Solution: Standard OC drainage uses garland drains + sump pumps.
Q15.7 The Chasnala Disaster (1975) was caused by:
A. Fire
B. Gas explosion
C. Inrush of water from old workings
D. Roof fall
E. Slope failure
Answer: C.
Solution: Over 375 miners died due to inundation.
Q15.8 Pumping arrangements are covered under:
A. CMR 121
B. CMR 124
C. CMR 126
D. CMR 127
E. CMR 131
Answer: C.
Solution: Regulation 126 = drainage & pumping.
Q15.9 Which system detects water before drivage?
A. Borehole drilling
B. Gas detectors
C. Fire hydrant system
D. Air shaft
E. Roof bolting
Answer: A.
Solution: Cover boreholes detect water hazards ahead.
Q15.10 TARP stands for:
A. Technical Action Recovery Plan
B. Trigger Action Response Plan
C. Training Action Relief Program
D. Technical Accident Response Procedure
E. None
Answer: B.
Solution: TARP = emergency water hazard management system.
Water is one of the most dangerous hazards in mining. Sudden inrush of water from old workings, surface sources, aquifers, or heavy rains can cause catastrophic mine inundations. Many of India’s worst mine disasters (e.g., Chasnala 1975) were caused by uncontrolled water hazards. The DGMS (Directorate General of Mines Safety) prescribes strict provisions under the Mines Act, Coal Mines Regulations 2017, Metalliferous Mines Regulations 1961, and DGMS circulars to prevent and control water hazards. Understanding these rules is critical for DGMS exams and for safe mine management.
⚠️ Types of Water Hazards
- Surface Water Inflow: Heavy rains, rivers, or surface reservoirs entering through cracks, shafts, or opencast benches.
- Old Workings: Accidental connection with water-logged abandoned workings.
- Aquifers / Water-bearing Strata: Sudden inflow during drivage of headings or shaft sinking.
- Overburden Dumps / Seepage: Water from OB benches or seepage through highwalls in opencast mines.
- Seasonal Hazards: Monsoon flooding in opencast pits.
💡 Prevention & Drainage Systems
- Survey & Plan Control
- Accurate plans showing adjacent old workings (survey within 15 m accuracy).
- Protective barrier thickness (Coal Mines Regulation 127).
- Shaft Sinking & Drivage Precautions
- Fore-poling, borehole drilling, and cover drilling ahead of face.
- Adequate pumping arrangements.
- Pumping & Drainage
- Main pumps with standby units (CMR 2017 Reg. 126).
- Sump capacity ≥ 4 hours maximum inflow.
- Regular inspection of pump houses.
- Opencast Mines
- Garland drains, sump pumps, dewatering wells.
- Bench sloping and catch drains.
- Storm water diversion channels.
- Monitoring & Emergency Measures
- Water gauges, borehole monitoring.
- TARP (Trigger Action Response Plan) for sudden inflows.
- Refuge chambers and emergency escapeways.
📑 DGMS Case Studies (H3)
- Chasnala Disaster (1975): 375 miners killed due to inrush from old workings.
- Kundra Pahar (2001): Fatal inundation in coal mine due to insufficient barrier.
- Opencast flooding (Jharkhand, 2019): Heavy monsoon inflow overwhelmed pit drainage.
📝 Quick One-Liners
- Old water-logged workings → biggest water hazard.
- Survey accuracy: 15 m (CMR 127).
- Protective barrier thickness mandatory between mine boundaries.
- Pumping capacity: Standby pump + 4 hours sump capacity.
- Garland drain + sump system = standard in opencast mines.
- TARP = Trigger Action Response Plan for water inflows.
- CMR 126 → drainage and pumping arrangements.
- DGMS circulars stress survey, boreholes, and risk analysis.
✍️ Descriptive Model Answer
Q: What are the statutory provisions and preventive measures for water hazards in coal mines?
Answer: Water hazards in mines are regulated under CMR 2017 (Regs. 126–128), which mandate accurate surveys, barrier thickness, pumping arrangements, and preventive boreholes. The main measures are:
- Surveys: Plans must show water bodies and old workings with ≤15 m accuracy.
- Barriers: Protective coal barrier thickness left between adjacent mines.
- Pumping: Main and standby pumps, sumps for 4 hours inflow, regular inspections.
- Boreholes: Cover drilling to detect water before drivage.
- Drainage: Garland drains, diversion channels, sump pumps in opencast mines.
- Emergency: TARP, escape routes, and training.
🎯 20 MCQs – Water Hazards (DGMS Exam Practice)
Q15.1 The most dangerous source of water hazard in underground coal mines is:
A. Aquifer seepage
B. Old water-logged workings
C. Rainwater inflow
D. Pump failure
E. High humidity
Answer: B.
Solution: Inundations mainly occur from old flooded workings.
Q15.2 Minimum accuracy of survey for detecting old water-logged workings is:
A. 30 m
B. 20 m
C. 15 m
D. 10 m
E. 5 m
Answer: C.
Solution: CMR 2017 requires ≤15 m accuracy.
Q15.3 Sump capacity must be at least:
A. 2 hours inflow
B. 3 hours inflow
C. 4 hours inflow
D. 6 hours inflow
E. 8 hours inflow
Answer: C.
Solution: Regulation 126 requires 4 hours inflow capacity.
Q15.4 Protective barrier thickness between adjacent mines is required under:
A. Reg. 124
B. Reg. 125
C. Reg. 127
D. Reg. 129
E. Reg. 131
Answer: C.
Solution: Reg. 127 covers barrier thickness.
Q15.5 DGMS mandates standby pumps because:
A. Save electricity
B. Handle peak inflow
C. Ensure pumping during breakdown
D. Reduce manpower
E. None
Answer: C.
Solution: Standby ensures safety if main pump fails.
Q15.6 In opencast mines, primary drainage system is:
A. Forepoling
B. Garland drains and sumps
C. Shaft pumps
D. Borehole drilling
E. None
Answer: B.
Solution: Standard OC drainage uses garland drains + sump pumps.
Q15.7 The Chasnala Disaster (1975) was caused by:
A. Fire
B. Gas explosion
C. Inrush of water from old workings
D. Roof fall
E. Slope failure
Answer: C.
Solution: Over 375 miners died due to inundation.
Q15.8 Pumping arrangements are covered under:
A. CMR 121
B. CMR 124
C. CMR 126
D. CMR 127
E. CMR 131
Answer: C.
Solution: Regulation 126 = drainage & pumping.
Q15.9 Which system detects water before drivage?
A. Borehole drilling
B. Gas detectors
C. Fire hydrant system
D. Air shaft
E. Roof bolting
Answer: A.
Solution: Cover boreholes detect water hazards ahead.
Q15.10 TARP stands for:
A. Technical Action Recovery Plan
B. Trigger Action Response Plan
C. Training Action Relief Program
D. Technical Accident Response Procedure
E. None
Answer: B.
Solution: TARP = emergency water hazard management system.
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