DesignEarthworks & Earth ResourcesGeneralSwales

Swale Calculator Spacing Tool

Douglas Barnes of permaculturereflections, who is a sustainable designer from the countryside in Tweed Ontario, has created a great tool that can be used to help with Swale implementation.

This calculator, located on his website here, addresses Swale spacing that has been a perennial question in Permaculture. This calculator turns the problem on its head and gives you the best estimate for spacing based on swale size.

Why calculate spacing?

Installing swales costs time, energy, and money. Over-installation of swales is a waste of resources. Under-installation is a missed opportunity. If you want to have an optimal system, you’ll need to calculate spacing. The good news is that now it’s easy with our calculator!

How spacing works

This calculator assumes you want to capture the maximum amount of water available on a site. There are plenty of times where you will not want to do this. Make sure you know whether swales are going to be helpful or harmful. See An Introduction to Swales and When Swales Can Kill for more information.

Remember that the figures given by the calculator are a guide. The will be an inherent margin of error. Spacing is based off the assumptions that your contour lines are going to be roughly parallel (they won’t be in the real world), and that your catchment area is going to be rectangular in shape (or at least an area with parallel edges). In practice, you might face an irregularly shaped catchment area. The calculator can still serve as a rough guide for you in these instances.

This calculator starts with the cross-sectional area of your swale. In other words, you design the size of the swale, and this calculator tells you the optimal spacing for that size.

The Permaculture Research Insitute

PRI Zaytuna Farm functions as a model farm (in development) and permaculture training facility. Geoff and Nadia Lawton, world-renowned permaculture educators and consultants, lead the project. Much of Geoff and Nadia’s time over the last few years has been spent away from the Institute, consulting and helping set up projects in diverse locales around the world. Seeing the worldwide demand for knowledgeable permaculture consultants and teachers increase exponentially, as fuel and fertiliser prices skyrocket and the effects of climate change, soil depletion and water shortages begin to hit hard, priority and focus is now shifting back to the Institute, where growing the training program will increase the output of quality teachers to help fill the growing need for them.

Leave a Reply

Your email address will not be published. Required fields are marked *

Check Also

Close
Back to top button