Build an Underground Water Tank with 8000-litre Capacity

The Underground Water tank is a high-quality and quantity tank compared to others. This is one of the best and most excellent water storing solutions for the building.

We can use this type of water tank while conserving space and maintaining an aesthetic view of the home.

With an 8000-liter capacity, such a tank can meet substantial water storage needs.

In this article, We explore step by step guide to constructing a safe and economical underground water tank for supplying 8k liters of water.

We will cover from Planning, estimation, and construction processes as everything related to the underground water tank.

Without wasting time let’s get started:

Planning and Preparation

Planning is very necessary for every project. without planning you will not meet your target and not be able to achieve the goal. So we need to plan and prepare for the underground water tank in the initial phase.

Assessing site conditions

Construction is not an easy job. Without proper planning and design the tank does not meet the standards.

We need the proper data on the soil type, Groundwater level, Terrain structures, and many things related to the Underground water tank.

If we have all the necessary data on the site conditions before starting construction then easily working on the field.

Assessing site conditions is very important before beginning the construction of a water tank.

Obtain permits and Approvals

This is also very important before beginning the construction of the water tank.

We should have full permission for the construction of an underground tank from the local authority and government.

This helps you to easily run the project without any issues.

Check with local authorities to determine if any permits or approvals are required for the construction of an underground water tank.

If we follow Rules and regulations ensure the safety and legality of the project.

Design of Underground Water tank

We should properly design the Water tank from a Qualified Engineer and Architect.

Plan, Elevation, and section should be designed and sizes are necessary from the engineer and architecture.

Engineers and Architecture should have designed the following factors:

  • size of tank
  • Height of tank
  • The capacity of the tank(for example 8000 liters)
  • Size of Reinforcement
  • Ration of Concrete
  • Access point

Excavation and site preparation

If we construct an Underground water tank after the construction of the home is not an easy step.

After we finish the planning and designing, we have to prepare for the foundation.

We need to decide in advance where and in what direction we will build so that we do not regret it later.

Marking and excavation

Now we have to mark the hole and dig the hole according to the marking.

We have to mark the size or dimension and depth as per the design.

For which the depth should go according to the measurement of the outline at the ground level, and then we can make the underground water tank as desired.

We should follow the precautions during the excavation of the foundation to avoid damaging underground utilities or structures.

like footing, sanitary lines, plumbing lines, electrical paths, foundation walls, and other structures.

Compaction and Leveling

Ensure the excavated area is properly compacted and leveled to provide a stable base for the tank.

Compaction prevents the tank from settling or shifting over time.

If the soil is already compacted during building construction they doesn’t require to compact.

After complete excavation according to the dimensions surface should be clear from debris and cutting soil.

Construction of the Water Tank

The planning phase is completed, and now we are going through the real construction field.

We should execute all the details from the design. Like concerning, Bar bending, formwork, etc.

Selection of Construction Materials

This is very necessary for the construction of a water tank for quality work.

We should select high-quality materials that are suitable for underground use.

Reinforcement, cement, sand, and aggregate should be necessary high quality.

These materials offer durability and resistance to corrosion.

Building the tank Structure

If the footing is necessary according to the design first we should execute footing for the base for the share wall.

After that, a 2″ brick should be solling. First-class or second-class brick should be used for brick solling at the same level.

If the brick solling is completed 3″ plain cement concrete is necessary. So PCC is required above the brick.

After completing brick solling and PCC then we should construct a 4″ or 9″ brick wall according to the nature and soil.

Construct the brick wall around the periphery as you can see in the picture.

After that Reinforce structure is necessary to withstand soil pressure and external loads. So that sharewall should be necessary after the completion brick wall.

For that tank capacity of 8000 liters, we should construct a 4-5″ share wall. We make a 4″ share wall for an 8k liter capacity underground water tank.

Note: Verticle reinforcement and horizontal reinforcement spacing should have a minimum of 6″ c/c.

We use 8mm to 10mm reinforcement for the vertical member (sharewall).

Installation of inlet and Outlet Pipes

Install inlet and outlet pipes to facilitate the filling and draining of the tank. Position these pipes to ensure efficient water flow and easy access for maintenance.

The proper plumbing system is necessary for the inlet and outlet. We can use GI Pipe, PPR pipe, and CPVC pipe as a plumbing system. For that professional plumber should be hired.

Waterproofing and Insulation

Apply a waterproofing membrane to the interior surfaces of the tank to prevent water leakage. Ensure proper sealing around pipe penetrations and joints.

Insulation is provided in the tank to minimize heat loss or gain depending on the climate.

Insulation helps maintain water temperature and reduces energy consumption for heating or cooling. This is not necessary but if you insulation system the water is not affected by the climate conditions.

Backfilling and Covering

Carefully backfill the excavated area around the underground water tank, layering soil and compacting.

Proper strength Cover should be used in the Tank Access to withstand normal load on it. If possible concrete tank cover is used.

Soil filling is in thin layers to avoid damage to the tank walls. Pay attention to proper drainage to prevent water accumulation around the tank.

Once backfilled, cover the tank with soil and landscape the area as desired. Proper grading to divert surface water away from the tank and prevent erosion.

Maintenance and Monitoring

Periodically inspect the tank for signs of damage, leaks, or deterioration. If any issues are found promptly to prevent further damage and ensure the longevity of the tank.

Schedule regular cleaning and maintenance of the tank to remove sediment and debris that may accumulate over time. Inspect and maintain inlet and outlet pipes to ensure proper function.


Building an 8000-liter capacity underground water tank requires careful planning and skilled construction. Strictly follows the regulatory standards. By following this guide you can successfully create a reliable water storage solution for your beautiful home. Remember to consult with professionals and obtain necessary approvals throughout the process to ensure a successful outcome.


What materials are commonly used for constructing underground water tanks?

Common materials include reinforced concrete and fiberglass, chosen for durability and resistance to corrosion.

How deep should an underground water tank be buried?

The depth varies depending on factors like soil type and local regulations but typically ranges from 1.5 to 2 meters.

Do underground water tanks require waterproofing?

Yes, applying a waterproofing membrane to the tank’s interior surfaces is essential to prevent water leakage.

How are inlet and outlet pipes installed in an underground water tank?

Inlet and outlet pipes are strategically positioned during construction to ensure efficient water flow and easy access for maintenance.

Is insulation necessary for underground water tanks?

Insulation is optional but beneficial, helping to maintain water temperature and reduce energy consumption for heating or cooling.

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