Hello,
I have a 3.5 acre pond that has a pretty steep hill leading up to the pond bank in a main area that we use to view the pond. It is about 12 feet down the hill and about 10 feet of drop. This bank is problematic for me as it always grows up in weeds and saplings and it's very unsightly and impossible to mow. I have been thinking of spraying the hillside with roundup(careful not to get near the water, then weedeating and raking the hillside, cover it with landscape cloth, anchor it the probably add some boards to run horizontally (to help hold in the mulch) then add 4" of wood chip mulch.
This would solve several problems but I worry that the run off of water that filters through the mulch may be to high in nitrogen. I know that wood chips above ground enhance the ground. Not sure about the pond though. I plan to add aeration but have not yet. The pond does get a little FA. There is also a lot of duck weed and some American pond weed and coon tail. I don't want to cause a negative reaction. Any thoughts on this?
Thanks,
gethooked
3.5 acre lmb, wc, bc, bg & re

I would look for an ornamental grass as a less risky solution. I have used amur silver grass on very steep hillsides but be careful. It is not allowed in some areas because it is invasive. It spreads by roots, so it is only good if you can keep it contained by mowing (or using herbicides like glyphosate) around edges. Also, this grass gets tall (over 6 feet on my place) and might block your view, but has ornamental value in all seasons. This grass also burns hot like most grasses, so be careful it is not planted where catching fire would cause damage. It does form a monoculture once established and prevents everything else from growing.

Other solutions:

https://www.nrcs.usda.gov/wps/portal/nrcs/detail/il/home/?cid=nrcs143_023569

IME as the wood chips decay, vegetation will grow right on top of the landscape cloth. The chips could also add tannins as the water filters thru. IMO I would use stone/rip rap.

+1 on the stone. Two layers of 4" plus rock cover will reduce the plant growth and make spraying with weed killer much easier and cost effective (once you get over the cost of the rock). I also like the idea of killing off the slope and getting a more desired plant to take over, but you will likely continue to fight the tree saplings unless your plant of choice is thick and tall (like 3 or 4 feet tall).

I'm afraid that mulch would end up washing into the pond under heavy down pours and it only takes a couple of years before mulch breaks down an turns into some fantastic top soil for more plants to grow, not to mention the nutrient load it would add to the BOW.

As others have said Rock would be the best way to go.

I have an experiment going currently using 4"-6" of hay on the back side of my dam. It has stopped the erosion/weeds and as it decays we are spriging coastal brumuda. While the hay looks ugly the brumuda that is coming in/spreading is a deep rich color of green.

Can you post a picture of the area?