Clean up muddy water left after hurricane
What I've done in the past for mud and other messes is to start with a garden hose to move the mud, using a basic sprayer head. You spray in an arc across the floor and try to get the water &amp; mess flowing in the direction you want.  You can use the squeegee broom mentioned by brhans to help with this. The water not only helps liquefy the mess to make it easier to flow away, but the movement and pressure does the work of moving it for you. You don't even need a pressure washer to get most things clean this way.

If you get really good at this, you can not only get large amounts of mud/mess off the floor, but you can get nearly 100% of it off. I've used the technique so much and figured it out so well that mops were essentially unnecessary for several things I've had to clean off floors. Getting the water to move correctly will prevent puddles and will leave not much more standing water than a mop will.
How thick and/or how large an area it is you need to work with determines your starting point. If it's not thick and not a large area, start at the farthest point away from your exit or drain. This gives you the best shot at getting it done in the fewest passes. And don't worry about trying to clean it all in one pass. With something as messy as mud, it'll likely take several passes, even if there's not much there.
If it's a lot of mud/gunk or it's a large area, start closer to the exit or drain. This allows removal of sections of mess and helps prevent it from flowing back on your already cleaned sections.
If it's really thick, as in more than an inch, then you need to shovel it out first, using a flat bladed shovel, like the image below, or a snow shovel or scoop shovel. Depending on where you need to get it, a wheel barrow, like Jim Stewart mentions, could do the trick. If you can't get one through a door, then 5 gallon buckets can work in a pinch.


Images included for example only.