How To Drain Your Pool Safely And Effectively
Draining a residential swimming pool requires careful calculation of hydrostatic pressure, local municipal discharge regulations, and surface protection measures to prevent structural collapse or liner damage. Most concrete, vinyl-liner, and fiberglass pools should only be completely emptied every 5 to 7 years to correct severe chemical imbalances, high total dissolved solids (TDS), or to perform major repairs.
Pre-Operation Planning and Equipment Checklist
Before initiating the drainage process, evaluating your pool's structural type, local environmental laws, and the condition of the surrounding water table is critical. Improperly managed pool water discharge can cause property erosion, sewer system overloads, or legal violations due to elevated chlorine and algaecide levels.
- Essential Gear and Tools: Submersible utility pump capable of moving at least 2,000 gallons per hour (GPH), heavy-duty discharge hose matching the pump's outlet diameter, garden hose for rinsing, stiff-bristle pool brush, neutralizer chemicals, and heavy-duty pliers or wrenches.
- Prerequisite Knowledge and Standards: Check local municipal codes regarding chlorinated water disposal (many cities require dechlorinating water down to zero parts per million before routing it to the storm drain or sanitary sewer). Verify that the local water table is low; heavy seasonal rains or high water tables can cause an empty pool to "pop" or float out of the ground due to hydrostatic pressure.
- Budget and Duration Benchmarks: Renting or purchasing a quality submersible pump costs between $80 and $250. The physical drainage process typically takes 12 to 24 hours depending on pool volume and pump flow rate, with an additional 12 to 48 hours required for refilling.
Step-by-Step Pool Drainage Workflow
Step 1: Dechlorinate and Test the Discharge Destination
Test the swimming pool water using a reliable DPD test kit or electronic photometer to measure free chlorine, combined chlorine, and pH levels. If chlorine is present above 0.1 parts per million, add a chemical chlorine neutralizer (such as sodium thiosulfate) according to the manufacturer's dosage instructions. Allow the water to circulate for two hours, then retest to ensure all sanitizers are fully depleted to protect local flora, fauna, and storm water systems.
Warning: Never discharge untreated, highly chlorinated, or heavily salted pool water directly onto neighboring properties, sensitive garden beds, or natural waterways, as this violates environmental protection statutes and destroys vegetation.
Step 2: Position the Submersible Pump and Discharge Hose
Lower your electric submersible utility pump into the deepest section of the pool, ensuring it sits level on the main floor without tipping over. Connect the heavy-duty discharge hose securely to the pump outlet using a metal hose clamp. Route the discharge end of the hose to an approved drainage point, such as a cleanout connected to your home's sanitary sewer system, or a heavily sloped yard that can absorb large volumes of water without flooding structures.
Pro-Tip: Tie a secure, heavy-duty nylon rope to the handle of the submersible pump before lowering it into the water; never lift or lower the pump by its electrical power cord, as this stresses the internal wiring and creates a severe shock hazard.
Step 3: Initiate Drainage and Monitor Water Levels
Plug the submersible pump into a Ground Fault Circuit Interrupter (GFCI) protected outdoor electrical outlet or use a heavy-duty outdoor extension cord connected to a protected indoor circuit. Monitor the pump continuously during the initial hour of operation to verify consistent water flow and check for kinks in the discharge hose. Depending on your pool's capacity, expect the process to run overnight; check the pump every few hours to ensure it is not running dry, which will burn out the motor.
Step 4: Scrub Interior Walls and Vacuum Debris
Once the water level drops to approximately one foot remaining in the deep end, unplug the pump and remove it from the basin. Use a stiff-bristle pool brush suited for your pool surface (nylon for vinyl and fiberglass; stainless steel for concrete/gunite) to scrub away settled algae, scale, and organic residue before the mud dries. Rinse the loosened debris toward the remaining puddle, and use a wet/dry utility vacuum or manual sump pump to remove the final inches of sludgy water.
Step 5: Begin the Refill Process Immediately
For vinyl-liner pools, you must begin refilling the pool with fresh water immediately after the final sludge is removed to prevent the vinyl material from shrinking, cracking, or pulling away from the coping tracks. For concrete pools, avoid letting the bare plaster bake in direct, high-intensity sunlight for extended periods, as rapid thermal expansion can cause structural cracking and delamination. Place garden hoses directly into the deep end of the pool and monitor the water level until it reaches the normal skimmer midpoint.
How To Drain Above Ground Pool With Main Drain at Nathaniel Ackerman blog
Pool Drainage Methods and Technical Parameters
| Drainage Method | Primary Equipment | Best Suited For | Risk Factor | Approximate Time |
|---|---|---|---|---|
| Submersible Utility Pump | Electric pump, discharge hose | All pool types (concrete, vinyl, fiberglass) | Low-to-Moderate (if monitored) | 12 to 24 Hours |
| Main Drain Hydrostatic Valve | Existing main drain plumbing | Concrete/Gunite pools with operational hydrostatic relief valves | High (risk of ground settling/floating) | 8 to 16 Hours |
| Municipal Tanker Truck | Professional pumping service | Emergency de-watering or commercial installations | Low (handled by professionals) | 2 to 4 Hours |
Common Site Failures and Field Fixes
- Root Cause: The pool shell floats or lifts out of the ground during or immediately after drainage.
- Actionable Fix: Always verify local groundwater tables before draining. If high groundwater is present, install a de-watering well point system outside the pool perimeter to lower the surrounding water table, or hire a professional hydrologist.
- Root Cause: Vinyl liner wrinkles, shrinks, or pulls out of the coping track during the refill process.
- Actionable Fix: Ensure no more than 1 to 2 inches of water are left standing when finishing the drain, and begin refilling immediately. If wrinkles appear as water covers the deep end floor, use a soft push broom to gently sweep the vinyl toward the walls while the water is only a few inches deep.
- Root Cause: Submersible pump motor stops running prematurely or trips the GFCI breaker.
- Actionable Fix: Check the pump intake screen for leaves, hair, and debris clogs. Ensure the electrical extension cord is rated for outdoor use and does not exceed recommended gauge lengths, which causes voltage drops and thermal overloads.
Frequently Asked Questions
How often do I actually need to drain my swimming pool?
Most residential pools only require a complete drain every 5 to 7 years. You should only drain the pool if you are experiencing severe Total Dissolved Solids (TDS) exceeding 2,500 ppm, persistent calcium hardness levels above 500 ppm that resist sequestering agents, heavy metal contamination, or if you need to perform structural plaster repairs or vinyl liner replacements.
Can I drain my pool completely on my own?
Yes, homeowners can drain their own pools using a rented or purchased electric submersible pump, provided they follow safety guidelines regarding electrical connections and local water discharge laws. However, concrete pools with faulty hydrostatic valves and vinyl-liner pools in high water table areas carry significant structural risks and are best managed by experienced pool service professionals.
What happens if I leave a vinyl pool empty for too long?
Leaving a vinyl-liner pool empty for more than 24 to 48 hours causes the vinyl material to rapidly contract and shrink in ambient heat. Once the material shrinks, it loses its elasticity, cracks along the seams, and pulls permanently out of the top track, requiring a complete structural liner replacement.
Is it safe to drain a pool into my backyard lawn?
Draining a pool directly onto your lawn is generally unsafe unless the water has been completely dechlorinated down to 0 ppm and adjusted to a neutral pH between 7.0 and 7.8. High chlorine concentrations, high salt levels in saltwater pools, and algaecides will immediately kill grass, destroy ornamental plants, and saturate the soil to the point of creating destabilizing mud pits around your home foundation.
Ensure your pool maintenance regimen protects your investment by consulting with certified local water management professionals before undertaking complex structural de-watering projects. Contact our expert team today to schedule professional pool evaluation and maintenance services tailored to your specific backyard environment.
