Run off from farmers field killing my fish

[bethbrooks12]

Does anyone out there know of what we can do to keep the run off from the farmer's field from damaging our pond and killing our fish? We have repeatedly ask the farmer to please come up with a solution. He was suppose to get a grant from the Govt (us USA TAXPAYERS) to fix the barrier between his field and our land. We stocked our pond with over $2000.00 worth of bass , cat, gills and amurs. We lost alot of them after a rain that washed his chemicals into our pond.

What can we do? We have been told that we can not change the flow of water. If we did , it would flood his field.