What Kind of Pump to Drain a Pool: A Complete Guide for Homeowners

Draining your swimming pool is an essential maintenance task that becomes necessary for a variety of reasons—winterizing the pool, making major repairs, or changing pool water due to chemical imbalances or contamination. However, selecting the correct type of pump is crucial for efficiency, safety, and avoiding damage to your pool equipment or property. With a range of pump options available, including submersible, above-ground, and sewage pumps, understanding the differences helps homeowners make informed decisions. This in-depth guide walks you through the best pool drainage practices, types of pumps suited for the job, and factors to consider when choosing the right equipment.

Understanding Pool Drainage Needs

Before exploring pump options, it’s vital to understand the conditions under which draining a pool is necessary:

Common Reasons to Drain a Pool

• Repairing structural damage such as cracks or leaks
• Maintaining proper water chemistry that can’t be corrected through treatments
• Winterization in colder climates
• Replacing pool liners or updating pool surfaces

Different scenarios may require different types of pumping equipment and drainage strategies.

Pool Drainage Challenges

Draining a pool introduces several technical and practical difficulties:

• High volume of water – Most pools hold thousands of gallons, requiring high-throughput pumps.
• Proximity to underground utilities and structures – Draining too quickly can affect nearby septic systems, foundations, or cause groundwater buoyancy.
• Water disposal regulations – Municipal and environmental codes may restrict where and how pool water can be drained, particularly due to chlorine content and heavy metals.

These points underline the importance of choosing the right equipment and following local guidelines.

Types of Pumps for Draining a Pool

While there are numerous pump types available, not all are suitable for draining a pool. Below is a breakdown of the most effective kinds:

1. Submersible Sump Pump

Overview

Submersible sump pumps are commonly used in basements to manage groundwater, but they can also be useful for draining shallow pools or collecting basins where the pump can be placed directly into water.

Pros

• Compact and portable
• Relatively affordable
• Easy to set up

Cons

• Lower flow rate (not suitable for large pools)
• Shorter operational time
• Risk of overheating if used for prolonged drainage

2. Pool-Specific Drain Pumps

Overview

Manufacturers offer electric or gas-powered pumps specifically designed to drain swimming pools. These pumps are usually part of a broader pool maintenance toolkit and come with long hoses, high flow capacity, and portability features.

Pros

• Designed for efficient water removal
• High flow rates (e.g., 60–120 gallons per minute)
• Often equipped with a filtration discharge option

Cons

• Higher initial cost
• May require professional support for optimal setup

3. Trash Pumps

Overview

Trash pumps are heavy-duty devices built to handle not only clean water but also water containing small debris such as sand, twigs, or leaves. These pumps are commonly used in construction or emergency flood situations and are a reliable option for pool drainage.

Pros

• Excellent for larger or contaminated pools
• High flow rates (100–250 gallons per minute)
• Durable and versatile

Cons

• Generally noisy and heavier
• Mainly gas-powered, which increases operational costs

4. Centrifugal Pumps

Overview

Centrifugal pumps operate by converting rotational kinetic energy into hydrodynamic energy to move water. These pumps are often used in industrial applications and are ideal for draining large commercial pools.

Pros

• High flow capacity (ideal for large draining jobs)
• Energy-efficient when operated correctly
• Flexible hose and discharge options

Cons

• Require priming before operation
• Potentially less portable than submersible or trash pumps

5. Water Transfer Pumps

Overview

Water transfer pumps, often powered by electricity or solar, are designed specifically for moving large volumes of water from one point to another. These pumps can be ideal for draining smaller to medium-sized pools when sustainability or energy cost is a concern.

Pros

• Energy-efficient operation
• Designed for clean water only, ensuring better filtration
• Useful in environmentally sensitive areas

Cons

• Suitable only for dechlorinated water
• Slower operation compared to industrial pumps

Choosing the Right Pump: Key Considerations

Here are the main factors to consider when selecting a pump for draining your pool:

Pool Size and Water Volume

Large pools (over 20,000 gallons) will demand pumps with higher flow rates, often measured in gallons per minute (GPM). Trash pumps and industrial-grade submersibles are the best choices for large above-ground or in-ground pools.

Drainage Location

Consider where the water will be expelled. Options may include storm drains, dry wells, or local waterways—each with specific regulations. Pumps with long discharge hoses or mobile bases are optimal here.

Pool Water Clarity

If your pool contains debris, using a trash pump with appropriate solids-handling capacity ensures smooth operation without clogging.

Power Source and Convenience

Gas-powered pumps tend to deliver faster drainage but come with higher noise levels and operational costs. Electric pumps are often preferred for quieter and more controlled draining in residential areas.

Time Constraints

Some pool owners may prefer to drain their pool overnight, while others may have more flexibility. Trash and centrifugal pumps significantly reduce draining time, especially for large pools.

Regulatory Compliance

Before draining your pool, check your local municipality’s regulations. Some areas require you to:

• Dechlorinate the water before discharge
• Avoid direct discharge to natural water bodies
• Prevent runoff onto neighboring properties

Ensure your pump setup and drainage plan comply with these standards to avoid fines or legal issues.

Proper Techniques for Pool Draining

Using the correct pump is just one part of the process. Proper execution is equally important for efficient and safe drainage.

Step 1: Prepare the Pool

Before initiating the draining process, ensure the following:

• Turn off all electrical components associated with the pool.
• Adjust water chemistry to neutral levels (especially chlorine) if required by local authorities.
• Remove any large debris from the pool surface to prevent clogging.

Step 2: Choose and Set Up the Pump

Select a pump that’s suitable for the water volume and quality. Position the pump on level ground and connect the discharge hose to your intended drainage outlet.

Step 3: Start Draining

Turn on the pump and monitor it regularly. Ensure the discharge area is free of obstructions and water is flowing smoothly. Some pumps may require periodic priming or adjustment based on water level.

Step 4: Monitor Water Level

Avoid draining the pool too quickly. For in-ground pools, leaving a few feet of water in the bottom can prevent structural issues caused by hydrostatic pressure or groundwater intrusion.

Step 5: Turn Off and Retrieve

Once drainage is completed, turn off the pump and disconnect all hoses. Allow the pump to cool down before storing it in a dry location.

Recommended Pumps for Draining Residential and Commercial Pools

Below is a comparison table of top-rated pumps ideal for pool drainage based on various use cases:

Choose a pump that aligns with your pool’s specific needs, including discharge requirements, budget, and operating time.

Maintenance and Safety Tips for Pool Drainage Equipment

Proper maintenance of drainage pumps ensures longevity and reliability. Here are some tips for pump care:

Regular Cleaning

After each use, clean the pump impeller and housing to remove any debris or sediment buildup, particularly after draining a contaminated pool.

Inspection and Lubrication

Check for wear and tear on seals, gaskets, and electrical connections. Lubricate moving parts according to the manufacturer’s instructions to avoid mechanical failure.

Winterization

In colder climates, store electric pumps in temperature-controlled environments and drain all water from gas-powered units to prevent internal damage due to freezing.

Safe Operation

Always follow the manufacturer’s safety instructions. Avoid using pumps near flammable materials, and use GFCI-protected outlets for electric pumps to reduce electrocution risk.

Conclusion: Choose the Right Pump for Your Pool Drainage Needs

Draining your pool, whether for maintenance, repairs, or seasonal changes, requires careful consideration of the pump type, size, and applicable regulations. A submersible sump pump might suffice for a small above-ground pool, but larger, in-ground pools may need a trash or centrifugal pump to handle the volume and potential debris. Understanding your pool’s specific features—such as water volume, location, and local guidelines—empowers you to choose the most effective pump for the task. Equally important is proper operation and maintenance of the pump to ensure efficiency and safety throughout the drainage process.

By following this comprehensive guide, you’ll be well-equipped to make an informed decision on “What kind of pump to drain a pool” and execute your drainage project with confidence, efficiency, and compliance.

Can I Use a Regular Water Pump to Drain a Pool?

Yes, you can use a regular water pump to drain a pool, but it’s important to choose the right type and size. Most standard water pumps, such as utility or sump pumps, are capable of handling pool water. However, they may not be as efficient or fast as pumps designed specifically for pool draining. When using a regular pump, ensure it can handle continuous operation and has the appropriate inlet and outlet sizes for your hose setup.

It’s also crucial to consider the pump’s capabilities regarding water volume and head pressure. Pool water can be quite heavy, especially when moving it over long distances or uphill. If you’re draining a large in-ground pool, a utility pump with high flow rates (measured in gallons per minute) is your best bet. However, for small above-ground pools or spas, a smaller pump may work just fine. Always disconnect the pump once the pool is drained to avoid damage from running dry.

What Is the Best Pump to Drain an In-Ground Pool?

The best pump to drain an in-ground pool is typically a high-capacity submersible pump or a dedicated pool pump with a built-in drain function. Submersible pumps are especially effective because they can be placed directly into the pool, reducing the effort needed to prime them. These pumps often offer strong flow rates and are designed to run efficiently for extended periods, which is essential for draining large volumes of water.

For homeowners who need to drain their pool regularly, investing in a pump with automatic shut-off features or a built-in timer can help prevent overflow or dry operation, which can damage the pump. Additionally, models with a self-priming function or dual-speed settings provide more versatility and energy efficiency. It’s also wise to pair the pump with heavy-duty hoses that can withstand prolonged outdoor use and resist UV degradation.

How Long Does It Take to Drain a Pool with a Water Pump?

The time required to drain a pool with a water pump depends primarily on the pump’s flow rate and the pool’s size. A pump that moves 7,000 gallons per hour, for example, can empty a 21,000-gallon in-ground pool in approximately 3 hours if operating at maximum efficiency. Smaller pumps, such as those commonly used for sump basins, may only pump between 1,000 to 2,500 gallons per hour, significantly extending the draining time for larger pools.

Factors like hose length, elevation changes, and water viscosity can also impact draining time. Running the pump at an upward angle or through a long hose will decrease its effectiveness. To speed up the process, minimize elevation changes and use the largest hose diameter compatible with your pump. Also, make sure to clean or replace any filters before starting to prevent clogs that might slow down water flow.

Can I Use My Pool Pump to Drain the Pool?

In many cases, a standard pool pump can be used to drain the pool, but it’s not usually the most effective method. Pool pumps are primarily designed for filtering and circulating water, not for emptying the pool completely. However, if you need to drain a small amount of water—such as lowering the level for winterizing or maintenance—your existing pump might work when connected to the waste line on the filter valve.

Using a pool pump for extended draining can cause it to overheat or wear out prematurely, especially if it runs without adequate water intake. To properly drain your pool, it’s recommended to use a dedicated transfer pump or sump pump that can handle continuous operation and higher volumes over time. These pumps are built for the specific purpose of moving large quantities of water efficiently and safely.

Do I Need a Submersible Pump to Drain My Pool?

While a submersible pump is not strictly necessary, it is often the most efficient option for draining a pool. Submersible pumps are designed to operate underwater, allowing them to effectively pull water from the deepest parts of the pool without requiring a manual priming process. This makes them ideal for tasks like completely draining a pool for repairs or winterization.

However, if you’re looking to drain only a small section of the pool or lower the water level slightly, a non-submersible pump like a utility pump or shop-vacuum system might be sufficient. These types of pumps are suitable for less intensive draining tasks but may struggle with high-volume or deep-water situations. Ultimately, choosing between a submersible or non-submersible pump depends on the scope of your draining project and how often you need to perform this task.

How Do I Choose the Right Pump Size for Draining My Pool?

Choosing the right pump size for draining your pool involves evaluating both the volume of your pool and the pump’s output capacity. Start by calculating the total gallons of water in your pool. Multiply the average width by length and average depth, then multiply that number by a factor that corresponds to the pool shape (rectangular = 7.5, round = 5.9, oval = 6.7). Once you have the total volume, look for a pump that can handle that water load efficiently.

Pump output is measured in gallons per minute (GPM) or gallons per hour (GPH). Larger in-ground pools benefit from pumps with higher GPM ratings, which help reduce downtime and labor. Also, consider the distance and height the water needs to be pumped, as this affects pressure and flow. For example, if you’re draining uphill or over long distances, a more powerful pump will be required. Always check the pump’s specifications and match them to your task to avoid unnecessary strain or underperformance.

Can I Drain Pool Water into My Yard or Sewer?

Draining pool water into your yard or sewer depends on local regulations and the condition of the water being drained. Chlorinated pool water can harm plants, soil, and aquatic life, so it’s usually unsafe to discharge it directly into your yard or storm sewers without proper treatment. Many municipalities also prohibit the disposal of chlorinated water into public sewer systems without prior approval.

Before draining your pool, consult your local water authority or environmental protection office to understand the guidelines in your area. If you plan to drain the water onto your property, ensure it is properly dechlorinated and that the discharge point allows water to be absorbed gradually without causing erosion or flooding. Dry wells, permeable surfaces, or connecting to a designated drainage ditch are safer options that comply with many local rules and protect the environment.