Participated in the full session with David Ahlgren during the PNW Permaculture Convergence. Great experience to be there for the layout and construction of the swale.  David is a great interactive instructor genuinely insterested in sharing, both ways. Good feedback on my questions.  In just the first 90 minute block of instruction, I'd gained enough to make all the attendance worthwhile. I'm glad I'll be able to visit Camp Singing Wind and see how the swale progresses, and I'm freshly enthused to tackle some earthworks projects at our place.