What is Dewatering and How do Dewatering Pumps Work?

Excess water is one of the worst things that can happen to a contractor eager to start a new job. This is why dewatering processes are so crucial to the preparation of construction sites. If the ground water levels are not handled properly, dewatering may delay project completion and cost you more money. There are various methods, techniques, and equipment are effective against these problems. Similarly, Florida dewatering has been the main problem at many construction sites.

In this article, we will discuss the details of dewatering, and various methods and pumps used for dewatering.

What is Dewatering?

A dewatering process involves removing groundwater or surface water from an area. In construction, dewatering is essential in creating drier and stable soils for site preparation and foundation excavation by lowering the surrounding water table.

Dewatering allows for stable excavation conditions, improves the sturdiness of the soil, and guarantees the welfare of workers. It is important to consider a wide range of methods when removing a small quantity of water in low lying excavations (about 1.5 m in depth) as well as controlling a substantial volume of water in deeper excavations (about 3 m in depth).

Methods Of Dewatering

A variety of information sources should be considered when making your decision. Consider the technical and construction site inspection and risk estimation conducted as part of your construction project. Consult with local authorities for any additional information you might need.

The four popular, effectively used methods for construction site dewatering are deep wells, eductor wells, sump pumping, and wellpoints. These practices can be independent or combined subjecting to the characteristic of the soil and underground water setup. Here we are going to look at how sump pumping works.

Purpose of a Dewatering Pump


A dewatering pump is a diffusing pump used wherever you need to eliminate water. You can use the pump at construction sites, waterfront properties, tunnels, mines, and establishments where you need to remove unnecessary water.

The kind of dewatering pump employed depends on what kind of fluid you will pump. If you need to filter water with granules, use a drain pump with a filter that blocks large stones from entering the pump. If you want to process water with solids, the dewatering sludge pump is an excellent option.

The dewatering pump does exactly what its name suggests: it removes water from a particular location and transports it to another. As a result, your home, business, or work site will remain dry.

How it Works

A dewatering pump works the same way as any other pump. Like a centrifugal pump, a dewatering pump utilizes a bladed impeller to begin and maintain the water’s movement.

Liquid flows into a smaller section of the impeller called the impeller eye. A diffuser, which looks like a cone-shaped discharge nozzle, is then used to direct water flow. The water’s velocity is reduced during this process, and the water flow’s energy is converted to pressure energy. A seven-to-ten-degree angle is then used to dispose of the water efficiently. An electric motor is most commonly used to facilitate the dewatering process, although some pumps use different motors.

Types of Dewatering Pumps

A productive dewatering process requires a dependable pump to lift water from below ground. Several dewatering pumps are available in the market including submersible pumps, centrifugal suction pumps, and well-pointing piston pumps.

Choosing the correct kind of dewatering pump is dependent on several aspects, such as the nature of underground water, the water depth, the local topography, the neighborhood habitat (metro or rural), and the discharge distance required for water.

An overview of the key features of each pumping system is provided below.

In a Submersible pump, the pump unit is lowered (partly or completely) in the liquid it is pumping. Submersible pumps propel the liquid to a surface release pipe. Submersible pumps have the leverage of being installed at the same surface as the water (instead of high above it). Moreover, a submersible pump generally needs less space for operation.

Another variety of pumping units is the Centrifugal suction pump. In this category of the pump, the unit is stationed above the ground. Hence, it necessitates an extended pipe for suction (or inlet tube) to be hauled into the water below. It brings the groundwater to the unit on the surface via centrifugal force. An outlet pipe then discharges the water, often into a dewatering pond or tank, far from where the pumping was done.

One more option for a dewatering pump is a Well-point Piston pump. The pumps offer automatic self-priming and are displacement pumps. This indicates that these pumps can work with water, air, or a combination of the two instead of using a different pump.

These pumps can function dry without endangering the unit. Around the job site, individual wells (known as well points) are drilled. Each well-point is typically 40 to 50 mm wide and varies in length based on the depth of excavation. These well-points are attached to a surface mounted, automatic self-priming pump.

Sump Pumping is a reliable choice in various situations, as well as the most effortless, economical, and successful method for dewatering.

Sumps are holes or areas underground (farther down than basement level) where water is accumulated and transported away for dumping. A foundation pit is fitted with drains and sumps on one or more sides or edges. Groundwater is gathered by the drains and dispatched into the sump. Once in the sump, it is steadily evacuated.

Sump pumping utilizes gravity instead of force. This technique is used in hollow excavation sites, where the soil has excessive gravel and sand and or gravel composition. If the excavation site is substantial, this system can utilize a trench and a slender, confined sump alongside the excavation site. The groundwater seeps into the excavation area, where dewatering pumps can easily remove it.

How to Pick the Perfect Dewatering Pump

A dewatering pump is useful in construction, removing greywater floods from basements or backyards, and even for cultivation purposes, including draining and transporting water from submerged fields.

Dewatering pumps are often used in construction, for removing greywater floods in basements or yards, and even for agriculture. You can also use a dewatering pump to drain a swimming pool. Fire departments use a dewatering pump in houses or apartment complexes to clear flooding and small rubble or even extinguish wildfires near water bodies.

Contacting a reputable company can help you with all your equipment needs. Find a good dewatering solution that is a reliable source for pump rentals and other professionals for your Florida dewatering needs.

Essential Dewatering Pump Requirements

As with all the other things, researching prior to buying or renting is important to get exactly what one needs. Check out these important requirements for water pumps.

1. Inlet Sizes

Dewatering pumps have different inlet sizes available from 1-inch to more than 4-inches. All of them work the same way, regardless of size. The difference in size means the bigger pumps can get the job done more quickly. You must use the same sized inlet or suction hose your pump has.

2. Dewatering Pump Low-Oil Switchoff Feature

All dewatering pump engines require lubrication to operate efficiently. This is achieved with engine oil, preventing the engine from malfunctioning. Dewatering pumps equipped with the low-oil switch off features automatically shut off when they detect a decrease in oil pressure, averting sudden damage.

3. Dewatering Pump Roll-Cages

A roll-cage can shield the pump if it topples or something falls on it. Using roll-cages on a construction site also gives cranes the ability to lift dewatering pumps.


Dewatering is an essential consideration for construction project managers in any project’s early planning, excavation, and foundation stages. As a reputable construction professional, you can ensure a solid foundation for your project, protect the environment, and prevent erosion. Florida dewatering can be a real problem if you are planning to start a construction project. The above given details will help you find out the type of dewatering method or pump that is most beneficial for your project.