It may be an extremely rainy season, you might be the victim of a small landslide or construction could be going on around your home--any of these things could have caused your swimming pool to become mud-contaminated. You can clean it with a powerful pump, some muriatic acid wash and a little bit of elbow grease.
Contact your city and ask them where to drain off your mud-contaminated swimming pool water--to the streets (which may lead to the ocean) or to the sewers. If the water is so thick with mud that its outpouring would only clog up the streets or the sewer, it would be best to drain out to the yard.
Shut off the electricity that is charging any underwater pool fixtures, such as the pool light, the filter or the heater. These items can be damaged if the water supply is suddenly cut.
Place pump and motor on the swimming pool deck as close to the pool as possible. Connect the intake hose to the vacuum head on the pump.
Throw the intake hose into the mud-contaminated pool.
Connect the output hose on the other side of the pump's vacuum head.
Position the output end of the hose where you need the grimy liquid to drain--into the street, into the sewer or into the yard.
Clean out as much muddy water as you can. The intake hose will be transferring the murky water until it becomes too heavy with mud. Do not let it try to transfer the cumbersome mud for too long or you may burn out the motor and the pump.
Shovel out the remaining mud at the bottom of the pool after you have drained off the watery mud. Scoop all this mud into the wheelbarrows. Dump these loads of mud from the wheelbarrows into your yard or into a vacant lot nearby.
Scrub your pool clean of any mud that is still clinging to your swimming pool shell. Now is a good time to clean your pool with an acid wash.
Mix 3 parts water to 1 part clean muriatic acid. Wash your entire pool down with the muriatic acid wash.
Fill your pool back up with water. Place your garden hose in the bottom of the pool and turn the water on as high as it will go. This process can take several hours.