A Numerical Index of Stream Health
As part of the Clean Water Act (CWA) (Section 101(a)), it is the obligation of each state to monitor and assess the chemical, physical, and biological conditions of streams within its boundaries. Therefore, states are required to consider the “biological integrity” of their waters when developing stream monitoring procedures (Berry and Dennison 2000). Biotic indices are accepted by the Environmental Protection Agency (EPA) as a method for assessing the biological health or condition of wadeable streams (Barbour et al. 1999).