When Is Groundwater Impact Assessment Required for an Industrial Project?

A Groundwater Impact Assessment is one of the most misunderstood documents in industrial groundwater approvals.

Many project owners first encounter the requirement while preparing a groundwater NOC application and assume that it is simply another consultant report to be uploaded to the regulatory portal.

That misses its real purpose.

A properly prepared groundwater impact assessment should answer a much more fundamental project question:

What effect could the proposed groundwater abstraction have on the aquifer, groundwater levels, nearby users and long-term groundwater sustainability?

For some industrial projects, the assessment is a regulatory documentation requirement. For others, even where it is not automatically triggered by a simple threshold, a hydrogeological assessment can still be valuable before major groundwater-dependent CAPEX is committed.

Under the CGWA framework, impact-assessment requirements depend on factors including the proposed groundwater withdrawal, groundwater-resource category and nature of the project. The current CGWA documentation framework identifies impact-assessment requirements for larger industrial withdrawals, while infrastructure projects involving significant dewatering have separate considerations.

What Is a Groundwater Impact Assessment?

A Groundwater Impact Assessment is a technical study of the groundwater system surrounding a proposed or existing project.

It typically examines three connected questions:

1. What groundwater system exists at the site?

This includes:

• regional geology;

• hydrogeology;

• aquifer characteristics;

• groundwater levels;

• groundwater-flow direction;

• recharge conditions;

• groundwater quality; and

• existing groundwater-development pressure.

2. How much groundwater does the project propose to abstract?

The study should connect groundwater withdrawal with:

• production requirements;

• process water;

• utilities;

• cooling;

• domestic use;

• existing abstraction;

• future expansion; and

• wastewater reuse.

3. What could happen after abstraction?

Depending on the project, the assessment may evaluate:

• drawdown around pumping wells;

• changes in groundwater levels;

• influence on nearby wells;

• cumulative abstraction;

• aquifer response;

• sustainability of withdrawal;

• recharge;

• groundwater quality considerations; and

• socio-economic implications.

CGWA's regulatory framework specifically recognises impact on the groundwater regime and socio-economic impacts as part of the impact-assessment concept for qualifying projects.

When Is Groundwater Impact Assessment Mandatory Under CGWA?

This is the question most industries actually want answered.

Under the CGWA framework, projects extracting or proposing to extract more than 100 m³/day of groundwater in Semi-Critical, Critical and Over-Exploited assessment units have been subject to mandatory impact-assessment requirements. The assessment is expected to address the effect of existing or proposed withdrawal on the groundwater regime and socio-economic conditions and is to be prepared through the applicable accredited-consultant route.

Current CGWA document-requirement information also identifies Impact Assessment Reports among the documentation for industrial applications involving groundwater requirement above 100 KLD, with requirements differentiated according to groundwater category and modelling needs.

That means the practical decision cannot be made from withdrawal quantity alone.

The project team should check:

Groundwater quantity+assessment-unit category+project type+current CGWA/State requirements

before deciding what study is required.

Is 100 KLD the Only Threshold That Matters?

No.

It is an important regulatory threshold, but treating it as the only groundwater decision rule would be too simplistic.

For an industrial project, groundwater-impact assessment may become technically important even where the proposed quantity is lower if, for example:

• the site is hydrogeologically sensitive;

• groundwater levels are declining;

• there are many nearby abstraction wells;

• the industry proposes multiple borewells;

• the project is located close to water-dependent communities;

• groundwater quality is problematic;

• expansion is expected;

• the existing abstraction is already significant;

• a State authority imposes additional requirements; or

• environmental-clearance or project-appraisal conditions require further groundwater evaluation.

CGWB emphasises that groundwater regulation must consider differences in groundwater availability and hydrogeological conditions across regions rather than applying a purely uniform approach.

Does the Requirement Differ Between Safe and Stressed Groundwater Areas?

Potentially, yes.

The project should first establish whether its assessment unit is:

• Safe;

• Semi-Critical;

• Critical; or

• Over-Exploited.

The earlier SARK guide on groundwater categories explains that these classifications represent progressively different levels of groundwater-development pressure.

For large groundwater withdrawals, current CGWA documentation distinguishes between requirements for stressed or OCS areas and Safe areas, including impact-assessment and groundwater-modelling documentation in applicable cases.

This is another reason why an industrial applicant should not begin by asking:

“Do we need an impact report?”

The better first question is:

“What is the current groundwater classification and regulatory pathway for this project location?”

That determines the rest of the assessment logic.

What Does OCS Mean in Groundwater Documentation?

OCS is commonly used in CGWA documentation for:

Over-Exploited + Critical + Semi-Critical

assessment units.

These are the groundwater-stressed categories in which larger groundwater withdrawals receive greater scrutiny.

Where an industrial project proposes significant abstraction in an OCS area, the study typically needs to demonstrate more than the existence of a productive borewell.

It needs to examine the impact of continued abstraction on the groundwater regime.

What About Industrial Projects in Safe Areas?

A Safe classification should not be confused with exemption from technical assessment.

Current CGWA documentation for larger industrial groundwater requirements includes impact-assessment and groundwater-modelling requirements in applicable Safe-area applications as well.

The distinction is important.

A Safe assessment unit means groundwater-resource stress is lower at the assessment-unit scale than in Semi-Critical, Critical or Over-Exploited units.

It does not mean:

• every location has abundant groundwater;

• every aquifer is productive;

• every borewell is sustainable;

• there are no nearby groundwater users;

• abstraction will have no local impact; or

• groundwater permission is automatic.

Local hydrogeology still matters.

When Is Groundwater Modelling Needed?

Groundwater modelling becomes useful when simple descriptive hydrogeology is not enough to understand how proposed abstraction may influence the groundwater system.

A model can help simulate questions such as:

• how groundwater levels may respond to pumping;

• how far the cone of depression may extend;

• how multiple wells interact;

• how abstraction may influence nearby users;

• how groundwater levels may change over time;

• how recharge affects the aquifer;

• how different pumping scenarios compare; and

• whether proposed abstraction appears sustainable under assumed conditions.

Current CGWA documentation references impact-assessment reports with groundwater modelling for applicable larger industrial withdrawals.

The quality of a model, however, depends heavily on the quality of its input data.

A sophisticated model cannot compensate for poor borewell logs, uncertain groundwater levels or unrealistic abstraction assumptions.

What Data Is Needed for a Groundwater Impact Assessment?

A useful industrial groundwater assessment usually combines several categories of information.

Project Data

The study should understand:

• project location;

• land area;

• industry type;

• production capacity;

• existing and proposed production;

• project stage;

• groundwater requirement;

• number of borewells;

• existing groundwater abstraction; and

• future expansion.

Water-Balance Data

This should include:

• total water requirement;

• groundwater contribution;

• municipal or other supply;

• process use;

• cooling use;

• boiler use;

• domestic use;

• washing;

• horticulture;

• wastewater generation;

• ETP/STP recovery;

• condensate recovery;

• RO reject;

• recycle; and

• rainwater utilisation.

Borewell Data

Important information can include:

• borewell coordinates;

• depth;

• diameter;

• lithology;

• casing;

• screen intervals where relevant;

• pumping rate;

• pump setting;

• yield;

• operating hours; and

• historical abstraction.

Hydrogeological Data

The study may require:

• geological setting;

• aquifer type;

• depth to groundwater;

• seasonal groundwater levels;

• recharge characteristics;

• groundwater-flow direction;

• aquifer parameters;

• nearby wells; and

• groundwater-quality information.

Monitoring Data

For operating plants, historic data can be especially valuable:

• water-meter readings;

• piezometer levels;

• groundwater-level trends;

• rainfall;

• production;

• groundwater abstraction;

• borewell downtime; and

• groundwater-quality results.

Good historical data can turn an assessment from a theoretical study into a much more defensible analysis of actual groundwater behaviour.

Why the Industrial Water Balance Should Be Prepared Before the Groundwater Study

A groundwater impact study should not begin with an assumed borewell requirement.

Suppose a factory proposes:

150 KLD groundwater abstraction

because its total daily water consumption is approximately 150 KLD.

After a proper industrial water balance, the project may discover that:

• 30 KLD of STP water can be reused;

• 20 KLD of condensate can be recovered;

• 15 KLD of cooling blowdown can be reduced;

• 10 KLD of washing water can be recycled.

The technically practical fresh-water requirement may then be closer to 75 KLD than 150 KLD.

That completely changes the groundwater question.

Therefore, before modelling groundwater impact, the project should first determine:

What is the minimum technically practical fresh-water requirement?

SARK's Industrial Water Audit work is designed around exactly this principle.

Existing Industry vs New Industrial Project

The groundwater-impact question differs between new and existing industries.

New Industrial Project

A greenfield project often has limited site-specific operating data.

The assessment therefore relies more heavily on:

• regional hydrogeology;

• nearby borewell information;

• baseline groundwater levels;

• proposed pumping;

• aquifer characteristics;

• project water balance; and

• predictive assessment.

The objective is to understand what may happen if the proposed groundwater abstraction begins.

Existing Industry

An operating factory may offer a much stronger evidence base.

The assessment can use:

• historic groundwater abstraction;

• borewell operating hours;

• water-meter data;

• production trends;

• groundwater-level records;

• piezometer data;

• rainfall;

• well-yield history; and

• changes in water demand.

This allows a much stronger question:

What has actually happened to groundwater while the plant has been operating?

For renewal or expansion, this information can be extremely valuable.

What Is the Role of a Piezometer?

A piezometer provides groundwater-level information separate from the production abstraction well.

This matters because measuring water level only inside a pumping borewell can make it difficult to separate:

• pumping drawdown;

• well losses;

• regional groundwater decline; and

• aquifer response.

Where groundwater monitoring is required, a properly located observation point can help track the relationship between groundwater abstraction and groundwater-level behaviour.

CGWA's groundwater regulation framework includes monitoring requirements and uses monitoring information as part of groundwater-management and compliance mechanisms.

For industrial projects, piezometer data should ideally be integrated with:

groundwater level + abstraction + rainfall + production

rather than maintained as an isolated monthly number.

How Should Nearby Groundwater Users Be Evaluated?

Groundwater does not follow property boundaries.

An industrial borewell may influence an aquifer that is also used by:

• neighbouring industries;

• villages;

• irrigation wells;

• residential colonies;

• commercial establishments; or

• public water-supply wells.

A groundwater impact assessment may therefore consider the surrounding groundwater-development environment, not merely wells located within the factory boundary.

This becomes especially important where multiple high-capacity wells are operating within the same aquifer system.

The study should examine whether proposed abstraction could contribute materially to cumulative groundwater stress.

What Is Drawdown?

Drawdown is the reduction in groundwater level resulting from pumping.

When groundwater is abstracted from a well, groundwater levels around that well can decline, creating what is commonly described as a cone of depression.

The magnitude and extent of drawdown depend on factors including:

• pumping rate;

• pumping duration;

• aquifer transmissivity;

• storage characteristics;

• recharge;

• aquifer boundaries;

• well design; and

• nearby pumping.

For a large industrial project, the practical question is not merely whether a borewell can yield the required flow today.

The more important question is:

What groundwater-level response is likely if this abstraction continues every day for years?

That is the type of question impact assessment and modelling should help answer.

Why Borewell Yield Is Not the Same as Sustainable Groundwater Abstraction

This distinction deserves emphasis.

A borewell test may show:

Yield = 20 m³/hour.

That tells the project something useful about the short-term performance of the well.

It does not automatically prove that:

20 m³/hour can be abstracted sustainably for the life of the project.

Sustainable groundwater planning must consider the wider aquifer.

A well may initially produce large quantities even while regional groundwater levels are declining.

Therefore:

Borewell yield = well-performance information

whereas

Groundwater impact assessment = aquifer and abstraction-sustainability evaluation

The two complement each other, but they answer different questions.

What Role Does Rainfall and Recharge Play?

Groundwater systems are replenished through recharge.

Depending on local conditions, recharge may come from:

• rainfall infiltration;

• surface-water bodies;

• irrigation return flows;

• canals;

• recharge structures; and

• other hydrological processes.

An impact assessment should therefore examine both sides of the groundwater balance:

groundwater entering the system

and

groundwater being removed from the system.

A project located in an area with relatively high rainfall does not necessarily have high groundwater recharge.

Recharge also depends on:

• soil;

• geology;

• land cover;

• slope;

• drainage;

• urbanisation;

• permeability; and

• aquifer conditions.

This is why rainfall alone is not an adequate groundwater-sustainability indicator.

Does Rainwater Harvesting Automatically Offset Groundwater Abstraction?

No.

For example:

100 KLD groundwater abstraction × 365 days = 36,500 m³/year

A rainwater-harvesting system may recharge some quantity of water, but it should not automatically be assumed that every cubic metre entering a recharge structure offsets one cubic metre of groundwater abstraction.

Losses, runoff, soil conditions, aquifer connectivity and recharge efficiency matter.

Rainwater harvesting is an important part of groundwater-management strategy, but its effect should be evaluated realistically.

What Is the Socio-Economic Impact Component?

Groundwater abstraction can affect more than the project's own borewells.

In groundwater-dependent communities, declining groundwater availability can potentially influence:

• drinking-water wells;

• irrigation;

• agriculture;

• neighbouring industries;

• local water costs; and

• community water security.

CGWA's impact-assessment framework for qualifying projects refers not only to the groundwater regime but also to socio-economic impacts.

This is particularly relevant for large abstraction projects in already stressed groundwater areas.

What Should the Groundwater Impact Assessment Ultimately Answer?

A good report should not end with 100 pages of geology and tables.

It should lead the project team toward clear engineering conclusions.

For example:

Is the proposed abstraction technically sustainable?

What groundwater-level change may occur?

Could nearby groundwater users be affected?

Is the proposed quantity unnecessarily high?

Can freshwater demand be reduced?

Is another water source needed?

Should abstraction be distributed among wells?

What groundwater monitoring should be installed?

What rainwater/recharge measures are appropriate?

What conditions should be monitored after the project starts?

Does future expansion require a different water strategy?

Those are decision questions.

When Should the Study Be Done?

For a groundwater-dependent industrial project, the ideal timing is often before final project water architecture is frozen.

Waiting until after:

• land purchase;

• borewell drilling;

• EPC award;

• equipment purchase;

• plant construction; or

• capacity expansion

can turn groundwater assessment into a compliance-repair exercise.

For large projects, it is more useful to perform groundwater due diligence during:

site selection → feasibility → water balance → groundwater assessment → regulatory strategy → final project design

rather than:

construct project → drill borewell → discover groundwater restriction → redesign water system.

Groundwater Impact Assessment Before Land Purchase

For industries with substantial water demand, groundwater due diligence can influence whether an industrial site is commercially viable.

Before acquiring land, assess:

• current groundwater classification;

• groundwater regulator;

• likely abstraction requirement;

• aquifer conditions;

• nearby wells;

• alternative supply;

• industrial-water infrastructure;

• treated-sewage availability;

• rainfall;

• wastewater-reuse potential; and

• future expansion.

The cost of this early assessment is usually small compared with the financial impact of purchasing a site whose water strategy later proves difficult.

Groundwater Impact Assessment Before Expansion

Existing factories should consider groundwater impact before increasing:

• production;

• cooling capacity;

• workforce;

• boiler load;

• washing;

• utilities;

• process lines; or

• groundwater pumping.

The assessment should reconcile:

existing permitted abstraction

vs

actual current abstraction

vs

future projected abstraction

and determine whether recycling or alternate supply can prevent fresh-groundwater demand from rising proportionately with production.

Groundwater Impact Assessment and Environmental Clearance

Groundwater assessment and Environmental Impact Assessment are related but not identical.

An Environmental Impact Assessment may evaluate a broad range of environmental aspects such as:

• air;

• water;

• wastewater;

• ecology;

• noise;

• land;

• waste;

• risk; and

• socio-economic conditions.

A Groundwater Impact Assessment is specifically focused on the groundwater system and the consequences of groundwater withdrawal or dewatering.

Depending on the project, groundwater studies can form an important technical input to wider environmental-clearance appraisal.

What If the Project Requires Construction Dewatering?

Infrastructure and industrial construction can sometimes require temporary groundwater dewatering for:

• basements;

• foundations;

• deep pits;

• underground tanks;

• utility trenches; or

• below-ground structures.

CGWA's current infrastructure-project documentation identifies an Impact Assessment Report by an accredited consultant in applicable cases where dewatering is involved, with requirements linked to the project and quantity.

Construction dewatering should therefore not be treated as an entirely separate issue from groundwater regulation.

Temporary abstraction can also influence surrounding groundwater levels.

Impact Assessment Should Not Be Prepared From Template Data

One of the biggest weaknesses in groundwater documentation is a report that appears technical but has little project-specific evidence.

A credible study should use actual or defensible data relating to:

• the project;

• the aquifer;

• water demand;

• borewells;

• groundwater levels;

• surrounding users;

• recharge; and

• proposed pumping.

The report should not merely repeat district-level hydrogeology from an old government publication and then conclude that the project will have “no significant impact.”

For a large industrial project, that conclusion should be supported by analysis.

How SARK Engineers & Consultants Approaches Groundwater Impact Assessment

SARK treats groundwater assessment as part of industrial project engineering and water-resource planning, not an isolated regulatory document.

The workflow typically begins with:

1. Regulatory Screening

Identify:

• groundwater category;

• jurisdiction;

• project type;

• existing/new status;

• proposed abstraction; and

• likely documentation pathway.

2. Industrial Water Balance

Determine actual fresh-water demand after accounting for:

• reuse;

• recycling;

• cooling optimisation;

• condensate;

• STP/ETP recovery; and

• rainwater.

3. Hydrogeological Assessment

Study the groundwater setting and aquifer system relevant to the project.

4. Borewell and Monitoring Review

Evaluate existing or proposed groundwater infrastructure.

5. Impact Evaluation

Assess likely groundwater-level and aquifer response under the proposed abstraction scenario.

6. Water-Management Strategy

Recommend:

• abstraction optimisation;

• alternative sources;

• reuse;

• recharge/RWH;

• monitoring; and

• future expansion safeguards.

7. Regulatory Documentation

Prepare the technical output required for the applicable project pathway.

This links the groundwater study directly with the wider Groundwater Regulatory Intelligence for Industries framework.

Frequently Asked Questions

Is Groundwater Impact Assessment mandatory above 100 KLD?

Under CGWA requirements, impact-assessment documentation becomes particularly relevant for industrial projects proposing groundwater extraction above 100 m³/day, with requirements varying according to groundwater category and current documentation rules. Projects in Semi-Critical, Critical and Over-Exploited areas above this level have specifically been subject to mandatory impact-assessment requirements.

Is groundwater modelling always required?

Not for every groundwater project. Modelling requirements depend on the project, abstraction quantity, groundwater category and applicable regulatory documentation. Current CGWA industrial documentation includes groundwater modelling in applicable larger-withdrawal cases.

Can Groundwater Impact Assessment be required in a Safe area?

Yes, depending on abstraction quantity and applicable project requirements. A Safe groundwater category is not itself an exemption from hydrogeological or impact-assessment requirements.

Is a borewell yield test enough instead of groundwater impact assessment?

No. A yield test assesses well performance, whereas an impact assessment evaluates the broader aquifer response, groundwater levels and potential effects of sustained abstraction.

Should a groundwater impact study be conducted before buying industrial land?

For water-intensive projects, it can be a valuable part of technical due diligence because groundwater feasibility can materially affect project CAPEX, operating risk and future expansion.

Does rainwater harvesting replace the need for impact assessment?

Not automatically. RWH can form part of the groundwater-management plan, but it does not by itself establish the sustainability of the proposed groundwater abstraction.

Does an existing factory need impact assessment during expansion?

It may, depending on the revised groundwater requirement and applicable regulatory framework. Even where not separately mandated, expansion is a sensible point to reassess groundwater sustainability and the plant water balance.

Who regulates groundwater impact assessment?

Where CGWA jurisdiction applies, the assessment forms part of the applicable CGWA groundwater-abstraction framework. In other jurisdictions, State groundwater authorities may have their own requirements. CGWB notes that groundwater regulation operates through CGWA guidelines while taking account of varying regional and hydrogeological conditions.