Electric water pumps are more convenient & quite often portable, quieter & economical to buy and to run than petrol driven pumps. Electric water pumps are great for a number of situations such as emergencies, or where they need to be run indoors and fumes would be a concern. Submersible water pumps are sealed against water ingress and can completely submerged below the surface of the water safely. Combined with a float switch they can be left to come on automatically and cut out out again when the water level drops to a preset level. Many sub pumps can pump floating solids and are suitable for dirty water.