You can find a lot of prior similar questions with responses in the Foundation link right under your question - also in the Home > Basement Waterproofing link in Browse Projects, at lower left.
Commonly this is not serious, and can be solved with either grout injection, or with a fast-setting mortar or epoxy grout on the interior wall, followed by pressure grouting if there is pressure behind the water that prevents direct grouting. in minor cases just a crack sealing mortar or a urethane sealant like Thoro makes will solve the problem if there is no buildup of water behind it.
It is also possible that this is a crack that fractured a water pipe or you have a leaking pipe that just happens to be showing up in the crack, though unlikely. Look where your hot and cold water pipes come in to the washer, and if possibly the source and water is coming out all the time, try turning off the water supply to those pipes (likely entire house will have to be shut off) for awhile and drain the water out of those pipes and see if the flow stops - if so, then broken or leaking pipe. If keeps coming in, then groundwater or surface water running down the foundation wall and in through the crack.
When refilling pipes, be sure to unhook washer and flush the air out of the pipes BEFORE reconnecting the washer - otherwise the air hammer can damage the valves in the washer and possibly split the hoses. Have seen that happen several times.
