Like 80 proof said, Japanese millet on bare banks may be the best bet. It is normally planted in late summer when your water will probably be at its lowest. It needs to be sown on bare soil. It won't germinate underwater. The millet is an annual and will need to be planted each year, but if you have vegetation year round, then you may be looking at algae problems. But then again, with a 1-12 foot depth you might not grow enough to worry about algae because most vegetation won't grow past 3-4 feet.