Does classification (wild, scenic, or recreational) have any affect on a federal reserved water right?

No. The United States determines the quantity necessary to protect flow-dependent outstandingly remarkable values.

 

Water law is a complex legal area, and water rights are a highly contentious issue. Whenever a water allocation issue arises, a river manager should consult with staff with water rights expertise and, as necessary, seek legal counsel.

Source
Interagency Wild & Scenic Rivers Council