Safe, Semi-Critical, Critical and Over-Exploited Groundwater Areas: What Do They Mean?
- Dr. Anubhav Gupta
- 11 minutes ago
- 11 min read
When an industrial project evaluates groundwater availability in India, one of the first terms it may encounter is the groundwater category of the assessment unit.
A location may be described as:
Safe
Semi-Critical
Critical
or
Over-Exploited
These terms are frequently misunderstood.
A Safe area does not mean that an industry automatically has permission to install a borewell.
Likewise, the words Over-Exploited do not by themselves provide a complete legal answer about whether every form of groundwater abstraction is prohibited.
They are fundamentally groundwater-resource assessment categories.
For industries, however, those categories can become extremely important because they provide an early indication of the stress on the groundwater resource at the location and can influence groundwater planning, regulatory review, water-source strategy, project feasibility and future expansion.
The Central Ground Water Board periodically assesses India's dynamic groundwater resources jointly with State and Union Territory agencies. Its current groundwater-resource portal includes the National Compilation on Dynamic Ground Water Resources of India 2025 and block-wise categorisation under GWRA-2025.
What Is the Stage of Ground Water Extraction?
The four major categories are based primarily on a quantity called the Stage of Ground Water Extraction.
In simplified terms:
Stage of Ground Water Extraction (%)
=
Annual Ground Water Extraction ÷ Annual Extractable Ground Water Resource × 100
CGWB describes the stage of groundwater extraction as the ratio between annual groundwater extraction and the annual extractable groundwater resource of an assessment unit.
This percentage provides a useful indication of the pressure being placed on the groundwater resource.
Imagine, for example, an assessment unit where the annual extractable groundwater resource is 100 units.
If annual groundwater extraction is 55 units, the stage of extraction is approximately 55%.
If extraction increases to 95 units, it becomes approximately 95%.
If groundwater withdrawal reaches 115 units against an annual extractable resource of 100 units, the stage of extraction becomes 115%.
The groundwater-resource situation represented by those three examples is very different.
That is why the categorisation matters.
What Is a Groundwater Assessment Unit?
One important distinction is often missed.
Groundwater categorisation normally applies to an assessment unit, not simply to an entire State.
Depending on the applicable assessment framework and location, the assessment unit may correspond to a block, taluka, mandal, watershed or another defined administrative or groundwater-resource unit.
Consequently, saying:
“Rajasthan is Over-Exploited”
or:
“Haryana is a Critical groundwater State”
is too broad to be useful for an individual industrial project.
Different assessment units within the same State can have very different groundwater conditions.
For industrial decision-making, the correct sequence is therefore:
Identify the project location → identify the relevant assessment unit → check its latest official classification → examine the regulatory implications for the specific project.
CGWB's current resource-assessment portal specifically provides block-wise categorisation under GWRA-2025 in addition to national and State/UT information.
What Is a Safe Groundwater Area?
Under the GEC-2015 categorisation framework, an assessment unit with a Stage of Ground Water Extraction of up to 70% falls within the Safe category.
At a resource-assessment level, this means groundwater extraction remains comparatively lower in relation to the assessed annual extractable groundwater resource than in Semi-Critical, Critical or Over-Exploited units.
But the word Safe can easily be misinterpreted.
For an industrial project, Safe should not be translated into:
“The borewell is automatically allowed.”
Groundwater-resource classification and regulatory permission are related but distinct questions.
Before an industry assumes groundwater can be developed, it should still determine:
the competent groundwater authority;
whether the project is new or existing;
the proposed quantity of abstraction;
the purpose of groundwater use;
the applicable groundwater rules;
existing borewells;
alternative water availability;
water conservation requirements;
monitoring requirements; and
other conditions applicable to the project.
Therefore, Safe is best understood as a resource-condition category, not a blanket groundwater approval.
What Is a Semi-Critical Groundwater Area?
A Semi-Critical assessment unit has a Stage of Ground Water Extraction of more than 70% and up to 90% under GEC-2015.
This represents a significantly greater level of groundwater development than a Safe assessment unit.
For an industrial project, Semi-Critical status should trigger a more careful question:
If groundwater dependence increases in the future, will the project's water strategy remain sustainable?
This is particularly relevant for factories expecting future expansion.
A new manufacturing unit may initially require 50 m³/day of freshwater but eventually increase production, workforce, cooling load, washing operations or utilities.
If groundwater has been assumed to be the default source for every future requirement, the project may develop a water constraint later.
A Semi-Critical classification therefore deserves attention during:
industrial land due diligence;
project feasibility;
water-balance preparation;
borewell planning;
capacity expansion;
rainwater-harvesting planning; and
wastewater reuse studies.
It is an early warning that groundwater should be managed as a constrained resource rather than an unlimited utility.
What Is a Critical Groundwater Area?
Under GEC-2015, a Critical assessment unit has a Stage of Ground Water Extraction of more than 90% and up to 100%.
The distinction between Semi-Critical and Critical is important.
In a Critical unit, groundwater extraction has approached the assessed annual extractable resource.
For a groundwater-dependent industrial project, this can materially increase the importance of:
accurate water-demand estimation;
alternative water-source evaluation;
treated wastewater reuse;
cooling-water optimisation;
rainwater harvesting;
groundwater monitoring;
project-specific regulatory assessment; and
future expansion planning.
A factory proposed in a Critical assessment unit should therefore avoid using a simplistic calculation such as:
Production requirement = 200 m³/day → proposed borewell capacity = 200 m³/day.
The better engineering question is:
How low can the facility's fresh-water requirement realistically be made before the groundwater abstraction requirement is determined?
This is where industrial water auditing and process engineering become directly relevant to groundwater planning.
What Is an Over-Exploited Groundwater Area?
An assessment unit is classified as Over-Exploited where the Stage of Ground Water Extraction is greater than 100% under the GEC-2015 framework.
Conceptually, this means annual groundwater extraction is greater than the assessed annual extractable groundwater resource.
It is the most groundwater-stressed of the four categories discussed here.
For industries, however, one important distinction should be maintained:
Over-Exploited is a groundwater-resource classification.
The regulatory consequences for a particular industrial project must still be checked against the rules and jurisdiction applicable to that project.
It is therefore risky to make either of these blanket statements:
“No borewell can ever be permitted in an Over-Exploited area.”
or:
“Our existing borewell means we can continue increasing abstraction.”
Both conclusions require a project-specific regulatory review.
An industry in an Over-Exploited assessment unit should evaluate its groundwater position particularly carefully before:
purchasing land;
constructing a new borewell;
increasing groundwater withdrawal;
expanding production;
replacing or adding borewells;
renewing groundwater permission;
changing its water balance; or
making groundwater availability a core assumption in project financing.
Safe vs Semi-Critical vs Critical vs Over-Exploited: Quick Comparison
The official GEC-2015 thresholds provide a straightforward technical framework.
Groundwater category | Stage of Ground Water Extraction | General resource interpretation |
Safe | ≤70% | Comparatively lower groundwater-development pressure |
Semi-Critical | >70% to ≤90% | Increasing groundwater-development pressure |
Critical | >90% to ≤100% | Extraction approaching assessed extractable resource |
Over-Exploited | >100% | Extraction exceeds assessed extractable resource |
The table should not be interpreted as a groundwater-permission table.
That distinction is fundamental.
Does Over-Exploited Mean Groundwater Is Physically Exhausted?
No.
The term does not mean that there is literally no groundwater remaining below the assessment unit.
It describes the relationship between annual groundwater extraction and the assessed annual extractable groundwater resource.
Groundwater systems are hydrogeologically complex.
An area may still contain substantial groundwater within its aquifers while simultaneously facing unsustainable extraction pressure.
An industrial borewell may even yield substantial water in a stressed area.
That does not automatically mean the resource is being used sustainably.
This is one reason why borewell yield and groundwater sustainability should not be treated as the same thing.
A high-yielding borewell answers:
How much water can this well currently produce?
Groundwater-resource assessment asks a different question:
What is happening to the groundwater resource across the assessment unit?
Does Safe Mean Groundwater Is Abundant Everywhere in the Block?
Not necessarily.
Groundwater-resource categorisation is an assessment-unit-level indicator.
Actual site conditions may vary because of:
local geology;
aquifer thickness;
fractures;
recharge conditions;
nearby groundwater users;
borewell depth;
well construction;
water quality; and
seasonal groundwater behaviour.
A Safe classification therefore cannot replace:
hydrogeological investigation;
borewell data;
groundwater-level information;
site-specific water-quality assessment; or
project-specific feasibility evaluation.
This distinction becomes increasingly important for large industrial projects.
Why These Categories Matter Before Buying Industrial Land
Groundwater is often investigated too late in an industrial project.
A developer may first evaluate:
land price;
road connectivity;
power supply;
labour availability;
proximity to customers;
industrial infrastructure; and
logistics.
Only after land purchase does the project team ask:
Where will 300 m³/day of water come from?
For water-intensive industries, that sequence can create major risk.
Groundwater due diligence before land acquisition should examine at least:
the latest groundwater classification of the relevant assessment unit;
the authority regulating abstraction;
expected project water demand;
availability of authorised alternative sources;
groundwater abstraction feasibility;
wastewater recycling potential;
rainwater utilisation potential;
future expansion demand; and
likely water-related infrastructure CAPEX.
Groundwater classification should therefore be treated as an industrial site-selection parameter.
Why Groundwater Classification Matters During Factory Expansion
The same problem arises in operating plants.
Suppose an existing factory has permission and infrastructure supporting a particular production capacity.
The company then adds:
another production line;
additional furnaces;
more employees;
a larger cooling system;
additional washing;
a boiler;
expanded utilities; or
new process equipment.
Production capacity may increase substantially while the original water strategy remains unchanged.
Before expansion, the industry should compare:
Permitted groundwater abstraction
with
Current actual groundwater abstraction
with
Projected post-expansion fresh-water demand.
If the assessment unit is already Critical or Over-Exploited, this review becomes particularly important.
Groundwater Classification Should Be Connected to the Industrial Water Balance
An industry's water requirement is not necessarily the same as its freshwater requirement.
Consider a plant with total water circulation of 500 m³/day.
Some of this water may potentially come from:
recovered condensate;
treated STP water;
treated ETP water;
cooling-water recirculation;
RO permeate recovery;
process-water recycling; or
collected rainwater.
The correct objective is therefore not:
“How large a borewell do we require?”
It is:
“What is the minimum technically practical quantity of external freshwater that this facility requires?”
This is precisely why industrial water audits, groundwater regulation and wastewater reuse should be considered together rather than as separate environmental activities.
What Should an Industry Do in a Critical or Over-Exploited Area?
The first response should not automatically be to abandon the project.
Instead, reconsider the water architecture.
Reduce Water Demand
Carry out a detailed water balance and identify:
leaks;
overflow;
excessive washing;
inefficient cooling;
excessive blowdown;
unnecessary freshwater use;
poor metering; and
process losses.
Increase Treated Water Reuse
Evaluate whether suitably treated wastewater can replace freshwater in appropriate applications.
Potential uses may include:
cooling-tower make-up;
flushing;
horticulture;
floor washing; and
selected process applications where water quality allows.
Optimise Cooling Systems
Cooling towers can represent a large freshwater consumer.
Water quality, cycles of concentration, blowdown and treatment strategy can materially change freshwater requirements.
Recover Condensate
Steam-intensive plants may have a substantial opportunity to return hot condensate rather than continuously replace it with freshwater.
Evaluate Rainwater
Large industrial roofs and paved areas can generate considerable seasonal runoff.
Depending on site conditions, rainfall can potentially contribute to:
direct storage;
non-potable use;
recharge; or
reduced stormwater stress.
Consider Alternative Authorised Sources
Municipal water, industrial-water networks, treated sewage and other authorised sources may form part of the project water mix.
Evaluate High-Recovery Treatment Carefully
RO recovery, reject management and Zero Liquid Discharge may be relevant in certain projects, but they should be selected from technical, regulatory and life-cycle-cost perspectives rather than treated as automatic solutions.
Does the Category Determine Whether CGWA NOC Will Be Granted?
Not by itself.
This is perhaps the most important takeaway from this article.
A groundwater category tells you about the resource condition of the assessment unit.
The regulatory decision for a project may additionally depend upon:
competent authority;
location;
industry/activity;
existing versus new status;
groundwater quantity;
proposed use;
alternative water availability;
applicable exemptions or restrictions;
monitoring arrangements;
water conservation;
reuse;
recharge requirements; and
current groundwater regulations.
Therefore:
Groundwater classification answers:
How stressed is the assessed groundwater resource?
Regulatory assessment answers:
What groundwater abstraction, if any, is permissible for this project under the currently applicable framework?
Those are related questions, but they are not identical.
How Should Industries Check Their Latest Groundwater Category?
Industries should use the latest official groundwater-resource assessment rather than rely on an old consultant report, historical NOC, search-engine snippet or copied online list.
CGWB currently provides the National Compilation on Dynamic Ground Water Resources of India 2025, State/UT fact sheets and block-wise GWRA-2025 categorisation through its groundwater resource assessment portal.
A practical review should establish:
1. Exact Project Location
District, tehsil/block/taluka and coordinates where required.
2. Relevant Assessment Unit
Identify which official groundwater assessment unit contains the project.
3. Latest Classification
Check the current assessment rather than assuming an older category still applies.
4. Competent Authority
Determine whether groundwater regulation for the project falls under CGWA or the applicable State framework.
5. Project-Specific Requirements
Only after these steps should groundwater-abstraction feasibility be evaluated.
Can Groundwater Classification Change?
Yes.
Groundwater-resource assessment is periodic.
Changes in recharge, rainfall, groundwater development, irrigation, urbanisation, industrial use and other factors can change the groundwater-resource position between assessment cycles.
That means a project that was located in one category during an earlier assessment may not necessarily remain in that category indefinitely.
CGWB's current resource portal itself publishes successive national assessments for multiple years and now lists the 2025 national compilation.
For industries, this has a practical implication:
Groundwater classification should be rechecked before major expansion, renewal, acquisition or new project investment.
Groundwater Category Is a Decision Signal, Not Just a Regulatory Label
For industrial management, the greatest value of groundwater classification is not the label itself.
It is the decision it triggers.
A Safe area asks:
Is our groundwater strategy still efficient and compliant?
A Semi-Critical area asks:
How will increasing groundwater pressure affect our future requirements?
A Critical area asks:
Can we materially reduce dependence on groundwater before expansion?
An Over-Exploited area asks:
Should groundwater remain a central assumption of this project's water architecture at all?
This is how groundwater-resource intelligence should enter engineering decision-making.
Groundwater Planning for New vs Existing Industries
New Industrial Projects
Before land purchase or major CAPEX commitment, determine:
groundwater category;
jurisdiction;
realistic freshwater demand;
alternative water sources;
recycling potential;
rainwater potential;
groundwater-monitoring requirements; and
future expansion demand.
The objective is to establish whether the site's water strategy is compatible with the project.
Existing Industries
Operating plants should periodically reconcile:
permitted abstraction;
actual abstraction;
meter data;
production;
water balance;
borewell status;
groundwater monitoring;
piezometer records where applicable;
RWH infrastructure;
wastewater reuse; and
expansion plans.
A legacy water arrangement should not automatically be assumed to remain suitable forever.
How SARK Engineers & Consultants Supports Industrial Groundwater Decisions
SARK Engineers & Consultants approaches groundwater as part of the wider industrial water and project system.
Support may include:
Groundwater Regulatory Review
Assessment of groundwater classification, jurisdiction, project status and regulatory pathway.
Groundwater NOC Technical Support
Project-specific technical and documentation support where applicable.
Industrial Water Balance
Determining actual freshwater demand rather than relying solely on gross plant consumption.
Hydrogeological assessment for projects where detailed evaluation is required or technically appropriate.
Measurement of water consumption, losses, reuse opportunities and potential reduction in freshwater dependence.
Rainwater Harvesting and Recharge Planning
Engineering assessment of catchment, rainfall, storage, recharge and stormwater infrastructure.
Wastewater Reuse and Recovery
Evaluation of ETP/STP treated-water reuse and high-recovery treatment options.
Project Groundwater Due Diligence
Groundwater and water-resource assessment before industrial land acquisition, expansion or major project investment.
For a broader project-level view, visit SARK's Groundwater Regulatory Intelligence for Industries in India hub.
Frequently Asked Questions
What percentage is considered a Safe groundwater area?
Under GEC-2015, an assessment unit with a Stage of Ground Water Extraction of up to 70% is categorised as Safe.
What percentage is Semi-Critical?
More than 70% and up to 90%.
What percentage is Critical?
More than 90% and up to 100%.
When is a groundwater area Over-Exploited?
When the Stage of Ground Water Extraction exceeds 100%.
Does Over-Exploited mean there is no groundwater underground?
No. It means assessed annual groundwater extraction exceeds the assessed annual extractable groundwater resource. It should not be interpreted as meaning that the aquifer literally contains no groundwater.
Can an industry automatically install a borewell in a Safe block?
No. Groundwater-resource classification does not itself constitute regulatory permission.
Should groundwater classification be checked before industrial land purchase?
For a groundwater-dependent project, yes. The classification can materially affect water-source planning, project feasibility, reuse strategy and future expansion.
Can an area's groundwater category change?
Yes. Dynamic groundwater resources are periodically reassessed, so industries should refer to the latest applicable official assessment rather than rely indefinitely on historical categorisation.
Regulatory note
Information status: August 2026
Groundwater classifications are periodically reassessed, and groundwater abstraction requirements can vary according to jurisdiction, location, project type and current regulation.
Industrial investment, borewell construction, expansion or groundwater-permission decisions should therefore be based on the latest official CGWB/CGWA or applicable State authority information and project-specific technical assessment.
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