If a wetland is drained or a dam is built to control the flow of water, fish can be impeded on their migration to spawning and breeding grounds (Roggeri 77).
(a wetland; is drained; ) (a dam; is built; to control the flow of water) (fish; can be impeded; L:on their migration to spawning and breeding grounds)
a wetland a dam fish
is drained is built can be impeded
to control the flow of water
L:on their migration to spawning and breeding grounds