Answer:
It depends on whether your land encompasses the stream or abuts it and how it was described in the deed description. If the stream is on your land in most jurisdictions in the US you cannot make any changes in the stream that would have any negative affect of the other land owners downstream. You cannot divert the water or block it in any way. Water rights are generally addressed by state laws. In the eastern part of the US those rights are referred to as riparian rights. In the Western part they are more commonly called usufructuary rights.