If you go to the first page of A20 Diary, it literally says water will be worked on in A21. They had initially said that they wanted to fix it in A20 but, since it will take a lot of work, they pushed it to A21. You should read the deveopment diary if you want to hear what the developers are doing or what their plans are rather than spewing nonsense.
That is caused by not all of your A19 files being deleted…..been posted about many times and in each case a correct cleaning and reinstall fixed this. You should bring up the game launcher, click on Tools tab, check everything then hit clean. Uninstall the game. Delete 7 Days and The Fun Pimps folders from steam apps->common and app data->roaming(or local, I forget) if present. If you had a mods folder it must be deleted. To be extra sure, pull up Regedit and search for any reference to 7Days and The Fun Pimps and delete. Before reinstalling, be sure that none is selected under betas tab then reinstall. If you do this and you generate that same map seed and your map still looks like that, then it is indeed a bugged rwg and should be reported in the Bug Report section so they can fix it.