radio network using xbee S3B' s, data to webpage

Hi, I’ve been asked to look into a job where customer wants to monitor irrigation outlets, 20-30 sites spread over an area of approx 30km end to end, at this stage only 2 digital inputs are to be monitored, data to be read on a web-page as gate open / gate closed.
I was thinking of Arduino serial-connected to Xbee S3B at each site in a mesh network. Not too sure how to get the data from the network of radios to the internet, i.e. what hardware is required.
Any advice?