The Permaculture Earthworks Handbook
Reviewed by Lorenzo Costa
When we study permaculture design and regenerative systems, we learn from the beginning that everything, from roads, access and structures at the bottom line are related to water. We deal with water to limit erosion, to build water retention in the soil, and to create water storage systems. Water is third on the list of Yeoman’s scale of permanence and this is no coincidence.
Water is not an easy subject, water is energy and life, and it can even be destructive if misunderstood and misused. Yet Douglas Barnes has been able to share a complex subject in a clear and easy way. When we think of water our first thought is: water flows downhill, but does it only do that? As designers in permaculture or regenerative projects, we learn to read water’s paths on the landscape.
This book is an essential, easy to read handbook to enable us to start working with water in all its complexity. It focuses on water cycles, hydrology, geology and climate, and then passes on to list different solutions and always includes cost/effectiveness analysis. Water in this erratic changing climate is becoming ever more important. Wars and conflict break out because of water, and have done so historically. Douglas Barnes reminds us about the importance of water in every civilization, recalling the story of Petra in Jordan. As designers this has to trigger our interest in researching ancient water harvesting and storage systems of the regions where we live.
Simple solutions for water harvesting are always the best. We can use permaculture design to understand what sort of system we need on a site. This is how the author helps the reader grasp this complex subject. Permaculture design breaks down complex questions by applying simple principles and helps us understand how to put water to use in different ways, as it is energy in evolution. Douglas Barnes reminds us throughout the handbook that water harvesting, from interception to storage, has to be done with caution. There is a chapter specifically on siting and building risks, but throughout the book he reminds us that certain earthworks require the presence of professionals. Every earthwork carries a potential risk.
We also need to consider the surrounding neighbors and the wider ecosystem. When designing, we can’t think only of what happens on our properties, we have to consider the bigger picture. Harvesting water has consequences, and overharvesting is an issue we can’t ignore. As the author says, “… water is yours to make use of, then pass on for others.” Often we forget this and focus only on ourselves, but being part of the ecosystem is observing and understanding the needs of the whole system.
Douglas Barnes describes a number of water storage and interception earthworks, from ponds and dams, passing through to swales, net and pan systems, and more. It is a pity though that the author goes into great depth on classic permaculture earthworks – swales and dams – that I consider best suited for big projects, but just skips through other solutions that could be of more interest to smaller projects – ponds are dealt with in just a few pages. Designing, siting, and forming dams and swales is a complex subject, and one that plenty of people will want to know, but a handbook should focus on a range of solutions with similar depth.
The interesting bibliography at the end of every chapter however, points the reader to more resources on specific topics that are briefly summarized in the book. Perhaps there is another book in him relating to smaller water systems! The book gives a range of tools for the designer to use, from laser levels and lidar mapping, to machines (bulldozers and excavators). There are also tools and advice for evaluating cost/effectiveness in relation to different systems.
The Permaculture Earthworks Handbook is full of practical knowledge and inspiration for ongoing research on a central issue for all of us: water.
Lorenzo Costa is a permaculture farmer living in Tuscany.