Excessive silt in underpass

I notice someone else has kindly reported the lighting failure in this underpass, but to make matters worse, there is a thick layer of silt/mud in the underpass. It's like walking through an almost dry river bed. As the lights are out, you can't even see the best path to walk, in order to avoid the deepest/wettest parts. Please can this be cleared up? The other underpass (crossing under the dial causeway, but at the other end of the school play field) to the park could also do with a clean up please, but it's not as bad as this one.