Regrading involves leveling your yard and changing how the water flows to make the path the water takes longer, thus slowing the water down. Slower water has a higher chance of being filtered into the ground and it does not erode (see homepage for an explanation) as much as faster moving water does. Rock features spread the water out over a larger area as opposed to channeling water in a narrow swale or ditch, which allows more of it to seep through pervious surfaces and decreases erosion. Rock features can also stop sediment in the water that would otherwise pollute waterways. You may want to hire a professional for these changes, but you could do them yourself.