Depending on the fish in the stream, you might not have to kill them off; saving $$ and time. Most stream fish aren't adapted to ponds, and while they will live in a pond, they won't thrive and most likely won't even spawn.

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).