CBLA Perennial Stream Determinations
The Perennial Stream Field Identification Protocol defines procedures for making field determinations between perennial and intermittent streams based on the combination of hydrological, physical and biological characteristics of the stream.
The North Carolina Division of Water Quality manual for identifying perennial and intermittent streams.
Chesapeake Bay Ordinance Guideline for Determining Water Bodies with Perennial Flow
US Army Corps of Engineers Wetlands Delineation Manual