Draining a swimming pool is not just about removing water—it’s a process requiring careful planning, preparation, and adherence to safety and environmental guidelines. Whether you need to drain the pool due to water quality issues, structural repairs, or a major renovation, this guide provides an in-depth understanding of how to empty your pool safely, efficiently, and legally in Australia.
Why Would You Need to Drain a Pool?
Emptying a pool should not be taken lightly, as it can affect the pool’s structural integrity, water chemistry balance, and even the surrounding environment. Here are the most common reasons why pool owners may need to undertake this task:
1. Extensive Repairs and Maintenance
Some repairs, such as fixing cracks in a concrete pool or replacing tiles, require a completely dry surface. Resurfacing or replastering the interior of a pool is another scenario where draining is unavoidable. An example could be that a homeowner in noticed significant cracks along the pool walls caused by shifting ground. Draining the pool allowed professionals to seal the cracks and stabilise the structure.
2. Severe Water Quality Problems
Sometimes, chemical imbalances make the water unsafe for swimming. Issues like high levels of total dissolved solids (TDS) or cyanuric acid that exceed 100–150 ppm can render the water unmanageable. Heavy algae infestations, often caused by poor filtration or insufficient chlorine, may also necessitate starting fresh with a refill. In severe cases of algae infestations or significant chemical imbalances, it may be necessary to drain the water to properly address the issue. Pools in regions with hard water, such as Perth, are prone to mineral build-up. High calcium levels can contribute to scaling and deposits that disrupt water chemistry.
3. Calcium or Metal Stains
Stubborn stains caused by calcium, copper, or iron can often require draining to properly clean and restore the pool’s surface. However, it is important not to leave an empty pool for prolonged periods to avoid structural damage. In areas like Perth, where bore water use is common, pools frequently develop rust-coloured metal stains. Draining allows for the application of specialised cleaning agents that can’t be used in a filled pool.
4. Environmental Considerations
Draining your pool can be a sustainable choice when performed correctly. For instance, repurposing the water for irrigation or ensuring safe discharge into a sewer system reduces the environmental impact. its worth noting that frequent draining can lead to structural issues like cracking or “pool pop” (where the pool lifts out of the ground). Always consider alternatives, like partial draining, before opting for a full empty.
Draining a pool comes with inherent risks, many of which are preventable with proper planning:
Hydrostatic Pressure
Hydrostatic pressure occurs when groundwater builds up beneath your pool, creating an upward force that can “pop” your pool out of the ground, particularly with fibreglass or concrete pools.
Preventive Measures:
- Open hydrostatic relief valves to allow groundwater to flow into the pool and relieve pressure.
- Check groundwater levels, especially after heavy rain, and wait for conditions to stabilise.
Structural Damage
Empty pools are exposed to sunlight and temperature fluctuations, which can damage the interior surface, particularly vinyl liners or plaster. Ground pools, in particular, face the risk of structural damage due to hydrostatic pressure when left empty.
Pro Tip: Schedule draining and refilling within a 1–2 day period to minimise exposure.
Environmental Impact
Improper drainage into stormwater systems can harm local ecosystems, introducing harmful chemicals like chlorine, salt, and algaecides to waterways.
Example:
- A local council require pool water to be dechlorinated and discharged only into sewer systems to protect the environment.
How to Prepare for Pool Draining
Proper preparation is crucial to avoid mishaps and ensure compliance with Australian regulations. Follow these steps before you start:
1. Turn Off All Electrical Equipment
- Power down pumps, heaters, and automatic systems to avoid electrical hazards during the draining process.
2. Check Local Regulations
Disposing of pool water improperly can result in fines. Contact your local council or water authority to determine the best disposal method. Typically, pool water must be dechlorinated before being drained into the sewer system.
Eg pool water to has to have chlorine levels below 0.5 ppm before disposal. Use a chlorine neutraliser or let the water sit for 2–3 days to allow chlorine to dissipate naturally.
3. Inspect Hydrostatic Relief Valves
Locate and test all hydrostatic relief valves to ensure they are functioning properly. These valves are critical for managing groundwater pressure beneath the pool.
Additionally, using a sump pump is important to manage groundwater pressure effectively.
4. Gather Necessary Tools
Prepare the following:
- Submersible Pump: A pump capable of handling high volumes of water.
- Discharge Hoses: Long enough to reach an approved drainage site.
- Safety Gear: Non-slip shoes, gloves, and eye protection.
- Water Meter: To monitor the flow and volume of drained water.
- Cleaning Supplies: Vinegar, descaler, or spa cleaner for calcium and mineral deposits.
Pro Tip: Avoid using extension cords with pumps to minimise electrical risks.
When to Drain Your Pool
Timing is critical when draining a pool. Poor timing can lead to unnecessary risks or complications:
1. Ideal Weather Conditions
- Drain during dry weather with temperatures between 12°C and 29°C. Avoid hot or rainy conditions that can either cause surface damage or exacerbate hydrostatic pressure.
2. Avoid Heavy Rain Periods
- Wait at least two weeks after significant rainfall to ensure groundwater levels subside, reducing hydrostatic pressure risks.
3. Schedule Supervision
Draining a pool can take 8–16 hours. Supervise the process to avoid issues like hose disconnections, pump overheating, or flooding.
Step-by-Step Guide to Draining a Pool
Follow these steps to drain your pool efficiently:
Step 1: Setting Up the Submersible Pump
- Place the pump at the deepest part of the pool.
- Secure hoses to a designated drainage point, ensuring the hose slopes downward for efficient flow.
- Before starting the pump, ensure that all drains are clear and functioning properly.
Step 2: Start the Pump
- Turn on the pump and monitor its operation. Adjust the hose position as needed to ensure steady water flow.
Common Problems:
- Slow Drainage: Check hoses for kinks or blockages.
- Pump Overheating: Pause the pump to allow it to cool if it becomes hot.
Step 3: Monitor and Adjust
- Continuously supervise the process to ensure the pump doesn’t run dry or malfunction.
Step 4: Final Water Removal
- Use buckets or a wet-dry vacuum to remove the remaining water that the pump cannot reach.
Cleaning and Maintenance After Draining
Once the pool is empty, use this opportunity to perform deep pool cleaning and necessary repairs:
1. Deep Clean the Pool Shell
- For calcium stains, use a vinegar solution or a commercial descale. Rust or metal stains may require specialised products.
- Scrub under the lip and in hard-to-reach areas to remove build-up.
2. Inspect for Damage
Look for cracks, leaks, or signs of wear on fittings and plumbing. Address these issues promptly to prevent further damage.
Inspecting the pool’s structural integrity is crucial to prevent future issues.
Example:
- A homeowner in Canberra discovered hairline cracks in their concrete pool after draining. Quick patching with epoxy resin prevented further deterioration.
3. Complete Repairs
- Fix tiles, regrout, or resurface the pool as needed. Ensure all repairs are completed within 1–2 days to avoid structural risks.
Refilling the Pool Safely
Refilling the pool is just as critical as draining. Follow these steps to avoid complications: Refill your pool promptly to avoid damage from external factors like sunlight.
1. Replace Hydrostatic Relief Valves
- Securely close all relief valves to prevent groundwater seepage during refilling.
2. Gradual Refilling
Use garden hoses to refill the pool slowly. A water meter can help track the fill rate and avoid overflows. Monitoring the water level during the refilling process is crucial to prevent overflows.
3. Balance Water Chemistry
- Test and adjust pH, alkalinity, and calcium hardness. Add chlorine in increments to ensure safe swimming conditions.
Pro Tip: In areas with hard water, like Perth, use a water softener to minimise calcium build-up during refilling.
Case Study: Effective Pool Draining in Practice
A family in Perth noticed severe calcium deposits along the walls of their fibreglass pool. After consulting local regulations, they drained the pool into an approved sewer system, scrubbed the surface with a commercial de-scaler, and refilled it within 24 hours. Using a water softener during refilling helped reduce future calcium build-up, and the pool was restored to pristine condition.
Conclusion
Draining and refilling a pool is a complex process requiring careful planning, compliance with local laws, and attention to detail. By following this guide, you can address water quality issues, structural repairs, and deep cleaning effectively while ensuring your pool’s safety, longevity, and environmental responsibility.