N.H. Rev. Stat. Ann. § 487:39

The general court finds that landscape changes and recreational and other uses of rivers and their watersheds have placed increasing stress upon the state's rivers, posing a threat to water quality and the continued support of designated uses. The general court recognizes the need for adequate data to identify the status of and trends in water quality as a basis for action, to restore, preserve, and maintain the state's rivers so that these significant environmental, recreational, and economic assets will continue to benefit the social and economic well-being of the state's citizens and support healthy ecosystems.