Highways problems such as potholes, flooding, overgrown vegetation, fallen trees, damaged kerbs, footpaths and verges can be reported on-line to West Sussex County Council (WSCC).
You can set up an account or you can file a report without logging in:
See file a report about potholes.
Alternatively, the WSCC Roads and Transport Team telephone number is 01243 642105.
You can also report problems anywhere in the country. See https://www.fixmystreet.com/