Winterizing your swimming pool is a critical task that determines the condition of your pool come spring. One of the most common and often misunderstood steps in this process is how far to drain your pool water before the cold hits. Draining too little can lead to costly winter damage, while draining too much may expose pool components unnecessarily to the elements. In this guide, we’ll walk you through everything you need to know to drain your pool correctly for winter.
Why Draining a Pool for Winter Is Necessary
Before diving into the depth question, let’s understand why drainage is an essential part of winterizing your swimming pool. In regions where freezing temperatures are common, water left in the pool can freeze, expand, and potentially cause cracks in the pool walls, plumbing lines, and equipment. Additionally, fluctuating water levels due to ice can create stress on the pool structure. Draining to the correct level helps prevent this damage, protect filtration systems, and reduce the chances of problems such as algae blooms or equipment failure during the off-season.
But, not all pools require the same treatment — your local climate, pool type, and cover system play a deciding role in how far you should drain the water. The key is to drain enough to avoid ice damage without risking damage to the pool itself — particularly crucial for vinyl liner pools and above-ground models.
How Far to Drain Your Pool Based on Pool Type
Pool type plays a major role in determining the appropriate water level for winter. Here’s a breakdown of recommended drainage levels for the most common pool types:
In-Ground Concrete (Gunite or Shotcrete) Pools
Concrete or gunite pools are extremely durable, but proper winterization is still essential. For these types of pools:
- Experts generally recommend draining the water level about 6 inches below the tile line or skimmer opening.
- This helps prevent ice from lifting or damaging the tile while allowing for adequate winter water coverage to protect the pool structure.
- In climates with mild winters, pool owners might not need to lower the water level as drastically, relying instead on a solid safety cover to manage seasonal freezing.
Vinyl Liner In-Ground Pools
Vinyl liner pools are among the most sensitive to improper water levels in winter. If the water is too high, freezing can damage the liner and structure; if too low, the liner may shrink or warp.
- Proper drainage for vinyl liner pools involves lowering the water level to between 4–6 inches below the skimmer.
- In some setups, automatic winter pool covers or mesh covers are installed over the lowered water level, so water levels are adjusted accordingly to accommodate the cover system without sagging.
Above-Ground Pools
Above-ground pools lack the structural support of in-ground installations, which means they are more susceptible to damage from ice expansion or external pressure (like snow or water weight).
- Draining is crucial, but not always mandatory depending on how the cover is used.
- Most recommendations suggest lowering the water level **at least 12–18 inches** from the pool rim.
- Many above-ground pool owners use a mesh safety cover, allowing snowmelt and rainwater to pass through, rather than rigid covers that require precise water levels.
- If using a solid cover, the water level is typically lowered more substantially, by up to 12 inches below the top rails or according to the manufacturer’s instructions.
Climate Considerations: How Cold Is Too Cold?
The next major variable in deciding drainage levels is the climate in which your pool is located. In places that experience sustained freezing — like New York, Michigan, or Canada — the need to lower water is much greater than in milder areas such as California or South Carolina.
Areas with Consistent Freeze Cycles
If you live in a region where freeze-thaw cycles are common, your risk of ice damage increases significantly. This means water levels in the pool should be set low enough to allow for ice expansion without damaging the pool structure or equipment.
- Drain to approximately 4–6 inches below skimmer (in-ground) or 12–18 inches down for above-ground pools.
- Ensure all skimmers are properly winterized (plugged).
- Use pool antifreeze in plumbing lines to further protect against freezing.
Mild Winter Zones (Non-Freezing Areas)
In warmer climates, the primary concern switches from freezing to water evaporation and debris buildup. In parts of Florida, Arizona, or Southern California:
- Draining may only be necessary to a depth of 2–4 inches below the skimmer.
- You may not need to use antifreeze in the lines.
- The main purpose is to protect equipment and install a durable cover, rather than full drainage.
How Your Pool Cover Affects Winter Drainage Needs
Choosing the right pool cover — and understanding how it works — can heavily influence how much water you need to drain during winterization. The two main types are solid safety covers and mesh covers, each with different requirements.
Mesh Covers: Advantages and Drainage Tips
Mesh covers allow rainwater and snowmelt to pass through into the pool, reducing the risk of water pooling on top. This makes precise water level less crucial.
- These covers don’t require aggressive drainage.
- Water levels can remain higher — around 2–4 inches below the skimmer.
- Mesh covers are ideal for areas with regular rainfall and snow as water drains away automatically.
Solid Covers: What You Need to Know
Solid vinyl covers are designed to completely seal the pool surface and require careful pre-winter setup, including proper water levels and leaf netting to support collected debris and ice.
- Water levels must be lowered much more for effective placement and weight support (6+ inches below skimmer lines for in-ground).
- These covers often require water bags or anchors to support snow and debris, preventing sagging into the pool.
- Improper water levels combined with poor drain-off may result in sagging that can damage the cover and risk the liner or pool walls.
Common Mistakes in Winter Pool Drainage
Draining your pool without full understanding of the various influencing factors is where most missteps occur. Learn how to avoid the most common errors:
Draining Too Far, Too Fast
Some pool owners mistake “lower is better” for maximum protection. However, this can backfire.
| Mistake | Result |
|---|---|
| Draining below manufacturer’s recommended levels. | Increased risk of liner shrinkage, wall collapse in vinyl pools, or hydrostatic pressure damage. |
| Neglecting to plug or winterize pool returns and skimmer lines. | Exposed pipes can crack during freezing weather without proper water levels or antifreeze. |
Draining Too Little
Not adjusting for the specific needs of your pool cover or regional freezing is another frequent winterization blunder. When the water is left too high, even during milder winters, seasonal temperature shifts can stress equipment and create overflow with rainfall or snowmelt.
Ignoring Local Weather Forecasts
Weather patterns are shifting. Sudden freezes or unseasonably warm temperatures may affect how your pool handles the winter. It’s important to stay up-to-date and adjust care routines accordingly.
Preventative Maintenance Steps Alongside Drainage
Draining alone won’t protect your pool throughout winter. Here are key steps to ensure full protection:
Shock the Pool Before Lowering Water Levels
Before any drainage occurs, test and balance pool water chemistry. Shock the pool to eliminate any lingering algae spores, and lower alkalinity and pH levels as recommended for winter.
Plumbing and Equipment Winterization
Draining helps, but if the plumbing isn’t winterized, freezing water can still cause cracks and leaks. Use an air compressor or blower system to drain lines and install skimmer plugs and gizzmos to prevent freezing.
Install the Proper Cover System
Whatever water level is selected, the right cover must be installed tightly and securely to withstand the weight of snow and ice and prevent debris from entering.
Regular Check-Ups During Winter
If you have the ability, visit your pool occasionally during winter to check for cover sag, water accumulation, or snow buildup that needs removal.
How to Lower Pool Water the Right Way
Knowing how far to drain is only half the equation — you also need to execute the step properly.
Step-by-Step Water Drainage Process
- Balanced pool water using test kits.
- Backwash or clean filters to reduce stress on the system in winter.
- Use a submersible pump or solar cover to roll away and begin draining water.
- Keep track of drop using a marked pole or string line to monitor progress.
- Ensure all equipment is turned off and winterized once target levels are achieved.
Knowing When to Stop
It’s easy to get carried away with lowering your pool during winter prep. Monitoring the depth as you drain is critical — especially when the water reaches 4 inches below the skimmer for in-ground pools or 12 inches below the rails on above-ground models. Use a tape measure or water level tool if needed.
Final Water Level Checks
Once drainage is complete, double-check the levels using a pool water level indicator or manually with a measuring device. Confirm that the levels align with:
- Manufacturer or industry guidelines.
- Local climate conditions.
- Cover type and setup requirements.
Conclusion
The right answer to “How far down should I drain my pool for winter?” depends on a combination of pool type, climate, and the type of winter cover you use. Following industry standards with attention to local conditions ensures that your pool remains safe, leak-free, and easier to open when spring arrives. Whether you own a gunite in-ground pool in Michigan or an above-ground in Missouri, proper water level management is one of the most important steps in pool winterization.
By understanding all factors — and avoiding costly mistakes — you protect your investment and ensure a smooth start to the next swimming season.
Why is it important to drain a pool correctly for winter?
Properly draining your pool for winter is essential to prevent damage caused by freezing temperatures. Water expands when it freezes, which can crack pool tiles, damage pipes, and even warp the pool structure if not adequately addressed. By draining the water to the appropriate level, you reduce the risk of ice formation in critical areas and allow for the effective use of pool covers and winterizing chemicals.
The correct drainage level depends on the type of pool you have—whether it’s an inground or above-ground pool—and the type of cover used. In general, you should drain the water just below the skimmer and return jets to avoid any freeze-related issues. However, over-draining can be just as harmful, leading to structural problems due to hydrostatic pressure from groundwater. That’s why it’s important to follow guidelines specific to your pool type and local climate.
How far should I drain an inground pool for winter?
For an inground pool, the recommended drainage level is usually about 6 to 8 inches below the skimmer. This allows water to be safely lowered away from sensitive equipment while still providing enough water to balance hydrostatic pressure from groundwater beneath the pool. However, if you’re using a solid winter cover, you may need to keep the water level slightly higher to support the cover and prevent debris accumulation in the deep end.
It’s also important to consider your geographic region and the severity of winter conditions. In colder climates where ice forms thickly, additional lowering might be beneficial. In milder climates, especially those without freezing temperatures, a minimal drop in water level may be sufficient. Always remember to winterize plumbing lines with a blower or compressor and install an air pillow under the cover to absorb ice expansion.
How far should I drain an above-ground pool for winter?
Above-ground pools typically require a different approach due to their construction and exposure to winter elements. The recommended practice is to lower the water level to about 1 to 2 inches below the bottom of the skimmer. Lowering it further could cause the walls to collapse inward, especially if the pool is exposed to heavy snow or ice. It’s critical to maintain structural integrity while preventing water from freezing inside the plumbing lines.
Additionally, pool owners using an off-season cover should ensure that the water level supports the cover without submerging it excessively. In some cases, manufacturers provide specific guidelines for your model of above-ground pool, so following those instructions closely is advisable. Winterizing chemicals should be added beforehand to keep the water balanced, and the cover should be secured properly to prevent debris and animals from entering.
Can I drain my pool completely for the winter season?
Draining your pool completely is generally not recommended, especially for inground pools, as it can lead to serious structural damage. Without water, the pool may shift or pop out of the ground due to hydrostatic pressure from the water table beneath it. Additionally, an empty pool is vulnerable to wind damage, liner tears in vinyl pools, and warping or cracking of concrete or fiberglass surfaces due to temperature fluctuations.
There may be situations where partial or total draining is necessary—for example, during major repairs or in extremely warm climates where freeze-thaw cycles are not a concern. In such cases, it’s strongly advised to consult with a pool professional to determine if it’s safe and what protective measures should be taken, like installing relief valves or using supports. If you must drain significantly, timing it near the beginning of winter should be avoided to reduce risk exposure.
What steps should I take after draining my pool for winter?
After draining your pool to the recommended level, the next step is to effectively winterize your equipment and plumbing lines. This includes blowing out the plumbing lines with a pool blower or air compressor to remove all water and prevent freezing and expansion inside the pipes. Use non-toxic antifreeze in the lines if necessary, especially in colder climates. Then, remove and store any removable equipment like pumps, filters, and heaters in a dry, warm location to avoid damage.
Once the plumbing is secure, clean the pool thoroughly and balance the water chemistry before installing the winter cover. A properly installed winter cover—whether solid or mesh—will protect the pool from debris, minimize algae growth, and preserve the drained level throughout the season. You may also want to add an air pillow under the cover to absorb the pressure of ice expansion. Routine checks during the winter can help ensure the cover remains intact and water levels stay balanced.
What if I live in a region with mild winters? Do I still need to drain my pool?
If you live in a mild climate where temperatures rarely dip below freezing, you may not need to drain your pool as significantly as someone in a colder region. However, it’s still a good idea to lower the water level slightly, especially if you’re installing a winter cover. This helps reduce stress on the cover and keeps the water free of leaves, dirt, and other debris that can accumulate during the off-season.
Even in warmer areas, proper winter maintenance is crucial. Water chemistry should be balanced and stabilized to avoid algae growth and staining. A mesh safety cover is often sufficient in these climates, since it allows rainwater and melting snow to pass through while keeping large debris out. In some cases, you may even continue using a solar cover to retain warmth. Regardless of your climate, preparing your pool for reduced use ensures easier opening in spring.
Can improper draining affect my pool’s water chemistry in spring?
Yes, improper draining can lead to major imbalances in your pool’s water chemistry when you reopen it in the spring. If too much water is removed, concentrated chemicals left behind can become overly potent or stain the pool surface. Alternatively, if you leave the water too high, rain or meltwater can dilute the chemical concentration, causing algae and debris buildup that must be treated post-winter.
Beyond just chemical balance, not draining enough can leave skimmers or jets exposed to freezing, leading to internal damage that affects filtration once the pool is back in use. Inaccurate winterizing may also result in a need to drain and refill the pool unexpectedly in spring due to poor water condition. That’s why careful water lowering, proper chemical treatment before closing, and a secure winter cover are key to a smooth reopening process.