How many gallons of water are stored in a water tower?

Water towers are a crucial part of many municipal water systems. Their primary purpose is to store and pressurize water for distribution throughout nearby homes and businesses. But just how much water do they actually hold? Let’s take a closer look.

What is a Water Tower?

A water tower is an elevated structure that is used to store a large supply of drinking water high above the ground. This stored water acts as a reservoir to meet the water demands of a community. The height of the tower provides the pressure to distribute the water. The water stored in the tower is connected to the mains water supply system.

Water towers come in different shapes, sizes, and designs. Some common types are spherical towers, fluted towers, composite towers, and standpipes. Modern water towers are often constructed using steel or reinforced concrete. Older towers were frequently built from wood.

The key components of a water tower include:

  • Water tank – Stores the water supply.
  • Support structure – Elevates the tank high above the ground. This is often a steel or concrete shaft.
  • Piping – Connects the tank to the water distribution system.
  • Valves – Controls water flow in and out of the tank.

Water towers are built tall so that gravity can provide the pressure to distribute water to homes and businesses in the vicinity. The elevation produces a minimum pressure of 35 to 55 psi as the water flows downhill through the distribution pipes.

Why are Water Towers Necessary?

Water towers serve several important functions in a municipal water system:

  • Pressure Maintenance – The height of the water tower provides pressure to the water pipes. This allows water to flow freely through the distribution system.
  • Water Storage – They provide a reserve supply of water to meet short term high demand periods. Often used to meet peak daytime needs.
  • Emergency Supply – The water volume in the tower acts as a backup in case pumps fail or pipelines break.
  • Water Quality Maintenance – The constant filling and emptying of the tank improves water quality by preventing stagnation.

Without water towers, many municipal water systems would struggle to provide reliable water access to local homes and businesses. The towers are an important backup water supply.

How Much Water do Water Towers Hold?

The amount of water stored in a water tower can vary considerably. It depends primarily on the size of the tank, which ranges from 50,000 gallons up to 2,000,000 gallons. Here are some typical water tower capacities:

  • 50,000 gallon water tower
  • 100,000 gallon water tower
  • 150,000 gallon water tower
  • 200,000 gallon water tower
  • 300,000 gallon water tower
  • 500,000 gallon water tower
  • 1,000,000 gallon water tower
  • 2,000,000 gallon water tower

Most municipal water towers store between 100,000 gallons and 500,000 gallons. Very large capacity tanks over 1 million gallons are more common in major cities.

The specific water volume needed depends on the population size served and their daily water demands. As a general rule, the tower should hold enough water to meet the average daily consumption rate.

Let’s say a town uses 500,000 gallons per day. The water tower for this town would need to store at least 500,000 gallons. It may store more (such as 750,000 gallons) to provide a safety buffer.

Typical Water Tower Capacities

Here are some approximate tank capacities for water towers based on the population served:

Community Size Water Tower Capacity
Village up to 5,000 50,000 to 100,000 gallons
Town up to 10,000 100,000 to 300,000 gallons
Small City 10,000 to 50,000 200,000 to 500,000 gallons
Medium City 50,000 to 250,000 500,000 to 1,500,000 gallons
Large City over 250,000 1,000,000+ gallons

These capacities are general guidelines. The exact size depends on the water demands, storage time requirements, fire flow capacity, and pressure needs.

Design Factors That Determine Water Tower Size

Several key factors go into determining the optimal size for a municipal water tower:

  • Average and peak water demands – Daily consumption rates dictate the base storage volume. Peaks require extra capacity.
  • Equalization storage – Extra supply to meet short term high demand periods.
  • Fire protection reserves – Capacity to pump water for fire emergencies.
  • Pressure requirements – Adequate water pressure depends on sufficient elevation.
  • Emergency storage – Backup supply in case of power failures or main breaks.
  • Regulatory requirements – Local policies may require specific storage volumes.
  • Operational factors – Tank refill time and water age impact size.

By analyzing these factors, civil engineers can determine the optimal tank size and tower height when designing a new water tower system.

Typical Water Demands

The below table provides typical water usage amounts for different types of residential and commercial consumers. This data helps size water towers to meet local demand.

Consumer Type Gallons per Capita per Day
Residential Homes 50 to 80 gallons
Schools 10 to 20 gallons
Hospitals 300 gallons
Hotels 100 to 150 gallons
Office Buildings 15 gallons
Restaurants 35 gallons
Industrial Plants 25 to 50 gallons

Multiplying the number of each consumer type by the typical per capita demand provides the overall water volume needed in an area. This is an important factor in water tower design.

Water Tower Construction Materials

Early water towers were made of wood staves and hooped together with steel cables. But modern water towers today predominantly use steel or reinforced concrete for construction.

Here are some of the most common materials used to build current water towers:

  • Steel – Steel water tanks provide great strength at relatively low costs. Many tanks have an interior coating to prevent corrosion.
  • Concrete – Reinforced concrete makes very durable towers. But concrete is more expensive than steel.
  • Fiberglass – Fiberglass tanks are strong, lightweight, and corrosion resistant. But upfront costs are high.
  • Plastic – Plastic tanks are inexpensive options for very small water systems. Not suitable for large towers.
  • Composite – Some modern towers use a steel core for strength with an outer composite shell.

Steel is the most popular choice today based on strength, price, and easy construction. Paint coatings help prevent corrosion on steel water tanks.

Common Water Tower Designs

While simple cylindrical designs were once standard, there are now many interesting water tower shapes and styles:

  • Spherical – A round ball-shaped tank that provides equal pressure in all directions.
  • Conical – Cone top tanks that slope inward to save steel costs.
  • Fluted columns – Decorative cylindrical towers with fluted draining panels.
  • Standpipes – Tall skinny tanks that maximize elevation and pressurization.
  • Composite tanks – Steel core with a decorative outer facade.
  • Reservoirs – Rectangular reinforced concrete structures.

The specific design is chosen based on storage needs, structural requirements, aesthetics, and cost.

Water Tower Costs

Constructing a new water tower represents a major capital expenditure for a municipality. Costs vary greatly based on the size, design, and location. But some typical price ranges include:

  • Small 50,000 gallon water tower – $200,000 to $300,000
  • Medium 250,000 gallon water tower – $500,000 to $1,000,000
  • Large 1,000,000+ gallon water tower – $2,000,000 to $4,000,000+

Many factors affect the overall project costs:

  • Size of tank
  • Tower height
  • Materials
  • Foundation requirements
  • Special coatings
  • Water quality
  • Labor rates
  • Accessibility

Ongoing maintenance is also required to keep water towers in good working condition. This includes regular inspections and periodic repainting.

Water Tower Funding

There are various options to fund new water tower projects, including:

  • Municipal bonds
  • State revolving loan funds
  • Federal grants and loans
  • Private equity partnerships
  • Revenue bonds
  • General budget funds
  • Utility customer fees

Most water towers are financed through municipal bonds, revenue bonds, or state revolving funds. Grants are highly competitive.

Water Tower Maintenance

Regular maintenance is crucial to keep water towers in good working condition. Typical maintenance activities include:

  • Inspections – Check for corrosion, leaks, safety issues.
  • Cleaning – Remove silt and debris buildup.
  • Testing – Sample water quality for safety.
  • Backflow prevention – Ensure no contamination enters.
  • Painting – New coatings prevent rust and corrosion.
  • Valve and pump servicing – Keep critical components in good repair.

With proper maintenance, most modern steel water towers can last 50 years or longer before needing rehabilitation or replacement.

Interesting Water Tower Facts

  • The first elevated water tank was built in 1866 in London.
  • Chicago built the first large-scale water tower system starting in 1869.
  • Early water tanks were made of redwood staves held together with steel cables.
  • The most common water tower design today is a spherical steel tank on a steel tower.
  • The first spherical water tank was built in Germany in 1928.
  • The tallest water tower in the world is the J-ville Water Tower in Indiana at 212 feet tall.
  • Water towers are sometimes nicknamed “peach towers” due to their shape.
  • Many towns paint logos or decorative scenes on their water towers.
  • The EPA regulates water towers as part of public drinking water systems.
  • Some towns have turned historic water towers into museums.

Frequently Asked Water Tower Questions

How does water get to the top of a water tower?

Water is pumped up to the tower tank from wells, treatment plants, or ground storage reservoirs using electric pumps. Check valves keep the water from backflowing down.

How does water leave the tower?

Gravity provides the pressure for water to leave the tower. Outlet valves open to allow water to flow into the distribution system. The height provides adequate pressure.

Can water towers run dry?

Yes, water towers can run dry if water usage outpaces the refill rate. Operators monitor tank levels to prevent this. Very low tank levels can allow air into the system and temporarily reduce pressure.

Do water towers ever overflow?

Water towers have overflow pipes near the top to prevent overflow. If the tank fills too high, excess water exits through the overflow outlet.

Are all water towers actively used?

Some water towers have been decommissioned over time as distribution systems change. But most active towers provide an important role in maintaining consistent water service.


Water towers are an iconic sight across many towns and cities. While often taken for granted, they provide crucial water storage and pressurization functions. Typical capacities range from 50,000 gallons in small towns up to over 2 million gallons in major cities. By understanding water demands and pressure requirements, civil engineers can design appropriately sized water towers to reliably deliver water.

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