Mines need a Comprehensive Hydrogeological Report for the CGWA NOC and as input to environmental clearance. Reviewers look for seepage estimates they can trace back to field data, and a plan that protects nearby wells and streams.
What the report should contain
- Aquifer geometry from drilling logs and geophysics (ERT, VES), and aquifer parameters from pumping tests.
- Water levels and well inventory across the study area, before and after the monsoon.
- Seepage into the pit for each stage of the mine plan, by empirical methods and a calibrated numerical model where seepage exceeds 500 m³/day.
- The drawdown cone and radius of influence, and the effect on villages, wells and streams.
- A dewatering design, a mine water management plan, and a monitoring network with trigger levels.
From our work
At the Tasra opencast coking coal mine in Jharkhand, stable isotopes showed that 70–80% of sump water is groundwater, which focused the dewatering design on the fractured sandstone. At the Surjagarh iron ore mine in Maharashtra, ERT traced seepage to a perched zone feeding fractures, leading to a five-tier control plan. Read the case studies.
General guidance based on the CGWA guidelines and amendments in force when written. Rules change; we confirm the current position for your site before you apply.