Ways to Drain Water From an Inground Swimming Pool

Using the right draining technique will ensure a safe and easy process.Swimming pool and pool house image by Jim Mills from Fotolia.com

If your in-ground swimming pool requires major repair or needs its total dissolved solids (TDS) stabilized, you may need to drain the water. While the project is potentially time consuming and environmentally hazardous, if you carefully select the best draining procedure for your pool, there´s no reason you cannot safely and easily empty it. However, to best avoid any problems, such as pressure imbalances with surrounding land, consult with a professional before beginning.

Using Main Drains

Most, though not all, pools feature one or more "main drain" elements. These are found on the swimming pool floor, situated at the pool's deepest point. Generally, they function as suction units that transport water into a pipe leading to a pump and filtration system before recycling the water back into the pool. The main drain is identified visually by its cover with grid-like holes. You can also feel the gentle suction of a main drain in operation. While the main drain's purpose is not usually to drain the pool as you would drain a bathtub, in many models it is also used to empty the pool of water.

Instead of the main drain, many pool owners prefer to use a submersible pump, a trash pump or a pool cover pump to drain out their pool water. According to Wet Head Media, trash pumps offer the quickest drainage at a reasonable price. As of 2009, you can rent trash pumps from rental stores for under $100. Typically, a trash pump works with hoses with diameters of 3 inches or greater. Pool cover pumps tend to have slimmer hoses and can take somewhat longer to drain, ranging in drainage speeds from 170 to 1800 gallons per hour.

While some pumps offer extremely fast draining times, the Southern Nevada Water Authority recommends using low-volume pumps with rates between 12 and 15 gallons per minute (or 720 and 900 gallons per minute). For any higher rates, you must remain extremely vigilant to prevent problems. Whatever pump arrangement you use to drain the pool, you must also decide on the way you will dispose of the drained pool water. One way of responsibly draining, recommended by the Environmental Protection Agency, is to seek permission from local sewer operators or treatment plants to empty the water directly into the sanitary sewer system so that it is cleaned and reused. Another way of disposal, less practical in many areas, is to discharge the water into a place where it won´t contaminate local surface waters. It´s also advisable to dechlorinate the water before drainage to incur minimum contamination repercussions. Ideally, drain the water slowly into an area of dirt directly above your home´s sewer clean-out line to help reduce its copper and chlorine levels. In no circumstances should you drain directly into storm drains, which in many communities run directly into local streams and waters.