Planting Grass for Filtering Water:

I have a lot of water coming into my pond through a 12" inlet pipe. This pipe comes off of a creek that is fed from a near by corn field as well as other parts of my land that drain into it. The creek is maybe about 300 - 400' long with a few twists and turns (i've never actually measured) and is about 2' in depth in most areas. Most of the time and especially in the spring, water is flowing and a bit turbid / muddy by the time it makes it to my pond. The pond water always clears up in a few days but after a good rain the incoming water makes it muddy again. During the summer months when the creek is dryer I was wondering if it would be possible or worthwhile to try to plant grass or some type of vegetation in the creek so that it will filter some of the water before it dumps into my pond? Any ideas?

I have something similar that during heavy rains the water would carry dirt, sand and clay into the pond. This would not only turn my water color muddier but would overtime reduce the size of my pond by filling in an area with all of the dirt. So, I dug a hole about 15' deep and 30' long and 30' wide just above where the water entered the pond. Called it a sediment pond. It has reduced the amount of dirt being moved into my big pond and may help to reduce the dirty water. I have raised FHM's along with some cnbg and some GSH's in the sediment pond. They don't do all that well when the water is turbid in the sediment pond but I have grown out a few and add them to the pond.
It is working when it comes to reducing the dirt that did enter the pond because I have to dig it all out every other year because the sediment pond is full of dirt.

growing grass will help reinforce the banks but its not going to significantly reduce the amount of sediment reaching your pond.....you need to slow the water down to do that. A sediment pond is the best way to deal with the muddy runoff

I agree with TGW1...a sediment pond is your best but on reducing the soils being brought in during rain events.

As for grass....it would help if the water ran over a wide strip on land, but in a creek, if there is anyplace grass would grow, it will be growing there already...