Can I drain my pool water on the lawn?

Table of Contents

Quick Answer

You can drain your pool water on the lawn in most cases, but you need to be careful about a few things. The main concerns with draining pool water on the lawn are the effects of the chemicals, excess water, and temperature. As long as you drain the water slowly, spread it out, and don’t do it too often, draining on the lawn is usually fine. Test the water first and neutralize chemicals if needed.

Overview of Draining Pool Water on the Lawn

During swimming pool maintenance, you may need to drain some or all of the water from the pool. This could be for cleaning, repairs, closing down for winter, or other reasons. A common question is whether you can drain this water onto the lawn. In most cases, draining pool water onto the lawn is fine, but there are some important factors to consider:

Pool chemicals – Chlorine and other chemicals may damage grass and plants if too concentrated

Water temperature – Very cold or very warm water can shock grass
Water volume – Large amounts of water may lead to puddling or runoff issues
Frequency – Draining onto the same spot too often may cause problems

As long as you drain the pool water slowly, spread it out over a large area, neutralize chemicals, and don’t do it too often, draining onto the lawn is usually not harmful. But it’s important to take precautions.

Effects of Pool Chemicals on Lawns

The main concern with draining pool water on the lawn is the effects of pool chemicals, especially chlorine compounds. Here is how common pool chemicals impact grass and plants:

Chlorine – Excessive chlorine can burn and discolor grass. But at normal pool levels, it does not pose major issues.

Muriatic acid – This lowers pH and too much can alter soil pH over time.
Sodium bicarbonate – Baking soda raises pH. Excessive amounts could potentially alter soil.
Algaecides – High copper or silver levels may build up over time.

Salt – From saltwater pools. Excess salt can damage grass and plants.

The key is to test and neutralize the water first if chemical levels are very high. Also dilute any effects by draining slowly and spreading water out over a large lawn area.

Water Volume Concerns

When draining thousands of gallons of pool water onto a lawn, the sheer volume of water can cause some issues:

Puddling water – Low spots may gather excess water that takes time to absorb.
Runoff – Water may run off onto sidewalks, driveways, other property.
Erosion – Fast running water erodes and displaces soil.

Muddy conditions – Too much water leaves very muddy areas.
Grass damage – Prolonged submersion can suffocate grass plants.

You can prevent these volume issues by draining water slowly, using a discharge hose to spread water out, and alternating discharge spots.

Water Temperature Concerns

If there is a large difference between the temperature of the pool water and the outdoor temperature, it could shock or stress the grass. Situations to watch out for include:

Hot tub or very warm pool water drained in winter or fall.
Icy cold water drained in early spring before grass is growing.

Any sudden, drastic temperature changes to grass.

Test water temperature before draining. If there is a wide disparity, wait for temperatures to align closer before draining onto lawn. Or alternate with garden areas that can tolerate variances better.

Frequency and Location

When draining a pool onto a lawn, you don’t want to overload the same spot over and over. Alternate discharge points around the lawn’s perimeter to spread out any effects:

Wait several weeks in between draining onto the same spot.
Slowly move the discharge hose around the lawn’s edge to spread water out.
Alternate between front yard one time and backyard the next time.

Use a spray attachment to spread water out even more.

Spacing out where you drain water each time prevents buildup of chemicals or overwatering in one spot.

How to Drain a Pool onto a Lawn Safely

Follow these steps when you need to drain a pool onto the lawn:

Step 1 – Test Chemical Levels

Using pool test strips, test the chemical levels in the pool water you will be draining:

Check chlorine, pH, alkalinity, and cyanuric acid (if used).
Compare to ideal levels. Chlorine should be under 5 ppm.

Add appropriate chemicals to neutralize if any levels are very high.
Retest until the water is balanced.

This prevents discharging water with excessive amounts of chemicals.

Step 2 – Inspect the Lawn

Walk around the lawn area:

Look for very dry, water-starved areas to avoid.
Find any soggy spots that hold water already.

Plan discharge points to spread water out evenly.

Choose turf areas in decent condition and able to absorb extra water.

Step 3 – Be Ready to Adjust Flow

When ready to start draining, have full control over water flow:

Use pool pump and filter valves to adjust outflow volume.
Attach a discharge hose to direct water where needed.
Have someone man the hose and monitor drainage.

Shut off water immediately if any issues arise.

This allows maximum control to prevent flooding or runoff.

Step 4 – Drain Water Very Slowly

Start draining at a very slow rate of flow:

Truly a trickle, like 1-3 gallons per minute.
Allows soil and grass to absorb water instead of pooling.
Prevents washed out areas from fast flowing water.

Gives time to redirect hose if needed.

Once everything is handling water well, the flow rate can be increased moderately while still monitoring closely.

Step 5 – Spread Water Out Over Lawn

As you drain, move the hose around to different spots:

Slowly sweep discharge hose side to side.
Gradually make passes around edge of the lawn.
Alternate between front and back yard sections.

Use a spray nozzle to help disperse water.

Spreading water out prevents saturating one area.

Step 6 – Inspect During and After

As the pool drains, keep checking for issues:

Monitor for any puddling or runoff.
Look for muddy areas starting to form.
Ensure water isn’t collecting anywhere.

Stop and adjust flow rate if needed.

Then check the lawn the next day for very soggy or discolored patches. Take notes to improve process next time.

Special Precautions for Saltwater Pools

Saltwater pools use salt chlorine generators instead of regular chlorine. The sodium chloride levels make the water brackish. When draining a saltwater pool onto the lawn, keep these precautions in mind:

Test sodium chloride level and dilute if very high.
Discharge onto tougher grass varieties like St. Augustine or Bermuda.
Divert water if discharging onto sensitive plants.

Rotate discharge points to prevent salt buildup in soil.
Flush the area with fresh water after draining.

The salt can be healthy for the grass in moderation but take steps to prevent excess buildup.

Alternatives to Draining Pool Water on the Lawn

If you decide that draining the pool onto the lawn may cause issues, consider these alternate options:

Drain Onto Garden Beds or Trees

Gardens, flower beds, trees, and shrubs can often tolerate excess water and chemicals better than turf grass. Some options:

Direct water onto vegetable gardens.

Discharge into areas with trees, bushes, or shrubs.
Use for newly seeded annual flower beds.
Water grass alternatives like clover ground cover.

Just be sure to spread it around and not overload any section.

Allow Pool Water to Evaporate

For partial drains or lowering water levels, you can simply allow the water to evaporate naturally over time if conditions permit:

Turn off the pool pump so water is still.

Allow natural evaporation to slowly lower water level.
Remove pool cover to speed up evaporation.
This takes longer but concentrates chemicals in remaining water.

Evaporation works best in hot, dry, sunny weather.

Drain Into Sewer System

Many sewer systems allow pool drainage as long as chemicals are below certain thresholds and water is metered slowly. Check with your local sewer department on regulations in your area. Proceed with caution to prevent backflow issues.

Hire a Pool Draining Service

Professional pool companies can pump out old water and dispose of it properly offsite for you. This is safest for the environment but does have an associated cost.

Key Takeaways on Draining Pool Water on Lawns

To summarize the key points on discharging pool water onto a lawn:

Test and neutralize chemicals first, especially chlorine.
Drain very slowly to allow absorption into the soil.

Spread water out over a very large area.
Alternate draining locations around the perimeter.
Monitor flow and stop immediately if issues arise.

Be extra cautious with saltwater pools.
Don’t do it too often at the same spot.

When done properly under the right conditions, draining pool water onto the lawn is usually fine. But take steps to prevent damage or unnecessary stress to the turf. Consider alternatives if conditions aren’t optimal.

Conclusion

Draining your swimming pool water onto the lawn is permissible in most cases with some precautions taken. The main concerns are excess chemicals, water volume, temperature fluctuations, and frequency. Test the water for chemical balance first. Then drain extremely slowly onto the lawn while moving the discharge hose around to spread out over the largest area possible. Monitor closely for any issues arising. Alternate between the front and backyard each time you drain the pool. This will minimize any risk of damage to the grass. Consider diverting water to garden beds or evaporating naturally if the lawn cannot handle the drainage. With a careful approach, you can safely reuse pool water for irrigation without causing harm to the landscape.