See below for overviews of two-stage ditches and self-forming channels:
Approaches to Enhancing Ecosystem Services in Modified Headwater Channel Systems (fact sheet)
Building Better Ditches (fact sheet)
Building Better Ditches: The Self-Forming Channel (fact sheet)
Ecological Services of Constructed Two-Stage Agricultural Ditches (conference paper)
Steep slope and potential bank failure in a conventional ditch (left); vegetation establishment in two-stage ditch (right); aerial view of two-stage ditch (bottom).