WindowRock, welcome to the forum. Good to have another Coloradan join the fun. There are still fewer of us posting than the number you can count on one hand.
I'm a bit south of you near Dolores; I'm guessing by your forum name you are near Junction and the Colorado National Monument?
You will get many, many ideas and answers from the forum regulars. Give us ideas about your goals for the lake. We'll call it that, as it's over 10 acres.
Get ideas of the water quality, fertility(possibly very low), temperatures throughout the year at depths from the surface to maybe 15' down. Can you see any vegetation whatsoever in the water?
Because there are common carp in the BOW, I'm assuming it is either considered a warm water or cool water, not a cold water pond. You might try sampling a few times for other fish. Try a worm baited small hook under a bobber, a couple of artificial lures such as a Rapala and a Panther Martin, and something for catfish after dark. Could fish possibly come up the outflow from the river during high water events? There could be small populations of just about anything that lives in the Colorado.
Junipers (aka cedars), cottonwoods, Siberian elms all will make good cover for fish. It's considered better to anchor trees so they don't move around to where you'd rather not have them.
And when you way the mining operation dewaters the lake, do you mean they pump nearly or all the water out of it? If that's the case, then when it is dewatered, that would be the appropriate time to kill off the carp and anything else if they are present.
