text: Improved Polders | CivFanatics Forums
  Improved Polders 1.0
  Improved and reworked polders.
  Seilven Chieftain
  Seilven submitted a new resource:
  Improved Polders - Improved and reworked polders.
  Seilven, Mar 14, 2019
  Been thinking about this for awhile, and you nailed it.
  Something I was pondering was and added function so that polders shield any low lying lands from flooding the way flood barriers do, as well as an added improvement "artificial island" which unlocks along with floodbarriers and is available to all civs but you get a tech boost if you build at least three polders (small advantage for playing the Netherlands).
  Artificial islands can be built anywhere in coastal waters, and when seasteads are unlocked they can then be built on ocean tiles as well. They can also be used to "resurrect" drowned tiles.