The Keyline® Plan is a method of land design for soil and water conservation developed by Australian farmer and engineer P.A. Yeomans in the 1950's, and practiced widely throughout Australia ever since. My training in this design system came from Keyline® design's modern day emissary, Darren J. Doherty of the Regrarians (www.regrarians.org). This series is Andrew Millison's simple introduction to the design system, beginning with the very basics: understanding landforms to determine the potentials that each landscape possesses.
https://www.andrewmillison.com/
https://permaculturedesign.oregonstate.edu/