Big Sandy River
It may require an interstate compact to address the weatershed issues in the Big Sandy River basin. A river commission that reflected the acreage of the watershed by state would have roughly 50% representation from Kenucky, 25% from Virginia, and 25% from West Virginia. If defined by population within the watershed, Kentucky might have 60% of the vote while the other states had 20% each.
Links
Rivers of Virginia
Rivers and Watersheds of Virginia
Geography of Virginia