Across:
   7. Looked irate, but happy to be round about (6)
   9,10. 11 provided such poor water for the old HWS (3 3 2 3 6)
  11. Old water supply surges (5)
  13. Severely sad folk sometimes do as oddly stupid children (7)
  15. see 26dn
  17. Article on Ellison composition resembling earlier work (3 9 3)
  19. He might wear horns and do 'cluck' dance (7)
  21. Not entirely a pain in the ear to indulge (7)
  23. see 16dn
  24,27,28. Doom half-creature to sod in such setting? (3 6 2 6 6)
Down:
   1. Notwithstanding that limited, dismal thought... (8)
   2. ...bring child up... (4)
   3. ...to be a scholar and a virile male with masculine DNA (5)
   4. see 22
   5. Blokey and rough - one lost to evil (10)
   6. Contaminated fuel? Do readjustment (6)
   8. He prosecutes socialist crimes and those that test the limits (10)
  12. Preference for inadmissable material DA removed (10)
  14. Superficial affectation ruined hen / cock pix? (10)
      Rooster and hen pictures ruined by such superficial affectation?
  16,23ac. Suggest coming back with girl - no spicy dish (3 5)
      Invite to join with girl - no spicy soup in return
      A log sank sadly for invite
      Invite to join in firing koala guns - no turning back
  18. Ranks as a failed state (8)
      State of chaos: in no time a raft sank
  20. Joy of loud tulip blooming all about (6)
  22,4,25. Old tars hired for such appointment? (5 3 4)
  26,15ac. Took on more fuel and perhaps used up precious time (3 7)