Can I drain my Ottawa pool onto my lawn or will the chlorine kill the grass?

No, you should not drain chlorinated pool water directly onto your lawn — the chlorine concentration in pool water (typically 1-3 ppm) is high enough to damage or kill grass, especially if the water pools in one area rather than being distributed evenly. Even small amounts of chlorinated water can cause brown spots and dead patches that take weeks or months to recover in Ottawa's short growing season.

The chlorine in pool water is specifically designed to kill organic matter, which includes the beneficial microorganisms in your soil and the grass itself. When you drain thousands of gallons of chlorinated water onto your lawn, you're essentially giving your grass a chemical burn. This is particularly problematic in Ottawa because our growing season is already compressed — grass damage from chlorinated water in late fall means your lawn won't have time to recover before winter dormancy, leaving you with dead spots until the following spring.

The safe approach is to let the chlorine dissipate before draining. Stop adding chlorine to your pool and let the levels drop to 0.1 ppm or lower before draining — this typically takes 3-7 days depending on sunlight exposure and water temperature. You can speed the process by adding sodium thiosulfate (available at pool supply stores) which neutralizes chlorine instantly. Test the water with pool test strips to confirm chlorine levels are near zero before draining.

When you do drain, distribute the water over a large area rather than concentrating it in one spot. Consider draining to the street (check City of Ottawa bylaws first) or into a storm drain if available. For partial draining — like lowering water levels for winter closing — the smaller volume is less likely to cause damage if spread over a wide area of established lawn.

Be especially careful with saltwater pools — the salt content can be even more damaging to grass and soil than chlorine alone. Salt buildup in soil can prevent grass from absorbing water and nutrients, creating long-term damage that's harder to remedy than chlorine exposure.

If you're planning a full pool drain for liner replacement or major repairs, professional pool contractors typically have pumps and hoses to direct the water to appropriate drainage areas away from landscaping.