Swimming Pool Draining Tips

How to safely drain your swimming pool
September 12, 2023

Safe Swimming Pool Draining Tips Offered as Summer Closes

MSD encourages residents to drain pools in a safe, environmentally friendly way


Homeowners may soon begin to drain their pools as summer days come to a close. Proper draining of swimming pools is essential to the health of our local waterways and good relations with your neighbor. 

“Water containing chlorine can kill fish and other aquatic life in creeks and streams,” states MSD MS4 Program Manager Colette Easter. The average pool has a chlorine concentration that is 10 times higher than some aquatic life can withstand. MSD recommends that a pool sit for at least 10 days after chemical treatment before draining any water. 

Improper draining can also become a nuisance for residents and their neighbors by causing basement flooding, a backup, or flooding of yards. Homeowners may slowly drain chlorine-free water to a grassy area in their yard if it is large enough to absorb the water. Or, they can drain into a sanitary sewer cleanout if one is available on their property.

Please follow these guidelines when draining a swimming pool: 

  • Do not drain your pool during or up to 48 hours after a rain event.

  • Dechlorinate your swimming pool water before draining it. The pool should sit at least 10 days after chemical treatment before draining any water. 

  • Test the pool water to ensure that it is essentially chlorine-free before draining (about 0.1 parts per million total chlorine). Bubbling, cascading, or other forms of aeration will help to remove chlorine from water. 

  • The pool’s pH should be in a normal range of 6 to 8 before draining. 

  • Drain to a grassy area of the yard if it is large enough to absorb the water, or into a sanitary sewer cleanout, if one is available on the property.

  • Discharge water slowly, at no more than 30 gallons per minute, to prevent soil erosion, flooding, or damage to adjacent properties, including backups into homes and businesses.

For more information, visit LouisvilleMSD.org/WaterQuality or call MSD Customer Relations at 502.540.6000 with your pool draining questions.