Submitted by Debbie Willis on behalf of the Grounds Committee
Permaculture Potential #2: Water Management
Welcome to Permaculture Potential! This is a column from the Grounds Committee; we are excited to help educate co-op members (and ourselves!) about permacultures principles and techniques, with the eventual aim of proposing more permaculture projects to membership. This week we're talking about something that has been on many of our mind's lately, as our sidewalks cover with ice and Sunnyhill Lane fills with puddles: water management.
What is water management, permaculture-style?
Permaculture always focuses on whole systems, and manages inputs and outputs in a way that ensures the health of the whole ecosystem. In permaculture, water is optimally used while respecting the overall health of the watershed. We must always be mindful that water is an essential resource.
At Sunnyhill, we have issues with water on pathways and flooding in the common area and so we on the Grounds and Planning and Development committees feel that it is worthwhile to explore the possibility of managing and using this plentiful resource—wonderful water—in ways that could be productive and beautiful for every member of the co-op. These are all dreams for now; I want to stress that we don't yet have concrete plans or detailed knowledge of what might be possible at the co-op. But in the name of education, I want to give you a general sense of how permaculture approaches an abundance of water like we are fortunate to have at Sunnyhill.
Two approaches:
There are two basic strategies of water conservation and management on a permaculture property: storing water in the soil and diverting surface water to dams, ponds and/or tanks for later use.
First we want to slow, spread, and sink water as it falls from the sky into the soil.
Following this, the secondary goal, as Ben Falk writes in Resilient Farm Homestead, are to: capture as much water as is reasonably possible, store that water for dry periods, and distribute that water when necessary across the site.
1) Let's talk about the first objective: slowing and sinking water. We want to disperse the flow of water so it can infiltrate into soil, turning runoff into soak-in. Essentially, we want to make the water stroll, not run, through the landscape and for this we must shape the land in a way that facilitates getting water into the ground and storing it there. In permaculture, one harvests water in this way by directing it through terraces, seasonal rain gardens and ponds, water-infiltration swales, slow moving waterways, and dry creeks. Slowing and sinking the water allows it to feed trees and plants, produce food, and create lush, self-sustaining landscapes appropriate for leisure—children playing, adults sitting under the shade of trees, green-thumbs who want more space to garden.
See below for an image of swales:
(You can also see wonderful examples of swales in the film The Biggest Little Farm, where they make use of the technique in their orchard.)
2) Once you’ve made the best use of the fallen rainfall and stored that water in the soil, you’ll get runoff as the field capacity of soil is reached. (You might get this runoff straight away if your site’s watershed is in a bad shape.) At that point, you begin diverting and storing that water on the surface in ponds, rain barrels, and tanks. Please see below for an image of a permaculture pond:
Right now, many feel that we have a water "problem" at Sunnyhill. By using permaculture principles and design, we may be able to change that problem into an opportunity. This is something that the Grounds Committee and Planning and Development will be exploring to improve our sustainability score for funding as plans for the new-build unfold, with the aim of presenting a cogent and realistic plan to members.