Recently I had the opportunity to check out the earthworks performance where I installed a mainframe design in January 2015. I was contacted to sort out the dam wall and spillway as the client was concerned about its safety due to very little free board between the high water mark and the top of the dam wall.
Also installing two levelsill spillways on each backflood swale 1, as a primary spillway charging the lower dam and the other what I like to call an emergency spillway set 100mm higher than the primary spillway, this allows water to safely cross through a pipe to charge the lower dam and in big rain events safely allowing water to exit over the emergency spillway.
While on site with the machine I installed a lovely crossing dam replacing the exciting pipe at a gully crossing creating a real feature for the site that not only looks great and is functional and has been credited as an excellent ecological niche for increasing biodiversity and habitat.
If you want to learn more from David Spicer check out some of his courses here:
2 day Introduction to earthworks https://www.permacultureworks.org/permaculture-earthworks-course/
5 day earthworks course with Geoff Lawton https://www.permaculturenews.org/courses/earthworks-water-harvesting/
This earthworks course is a hands-on course that will help you design and implement water harvesting strategies on your property. Also, this course gives great value to enhance any serious consultant’s portfolio to have confidence when supervising contractors.
In this course, you will learn the theory and practice of Permaculture Earthworks – learning site design skills, surveying and directing earthmoving machines to establish dams, swales, terraces, access roads and more.