If you haven't planted grass on the exposed sides of the pond, do so ASAP. Until the fresh dirt is covered, any precipitation will wash more mud into the pond. Mulching over the seed with straw or hay will help speed up grass growth and should cut down a little on mud from runoff all by itself.

"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
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