Designing Roads as Water Features Using Scale of Permanence

The Misunderstanding About Where to Put a Road

There's a misunderstanding about where to put a road on the land. Most often we draw artificial lines on the landscape based on straight lines for our implements, aesthetics, or the views we want from our front porches. We think of roads purely as access. But a road is decidedly a water feature.

We all recognize this intuitively when the deluge starts flowing across our roads, perhaps cutting across, incising or simply turning them into a slippery mess. The question is whether we can be more purposeful in how we approach them from the beginning.

Understanding Scale of Permanence

Over 50 years ago, P.A. Yeomans developed what he called Keyline, or the Keyline Plan. It was designed for the development of agricultural land, based first on his conception of what soil is, how it developed naturally and how it can be further developed by applying the Scale of Permanence to the overall design of the landscape.

The Scale of Permanence is pretty much what it sounds like. It's approaching the land and designing it according to how readily each layer of design can be manipulated. Some things, like climate, can hardly be manipulated at all. Geography can be manipulated only slightly but falls in the category of foundational layers that are most difficult to change. Therefore all designs should embrace them and strive to work within the given framework in an effort to complement it, rather than fighting it.

Regrarians and the Order of Infrastructure Layers

Regrarians, developed by Darren Doherty, adopted the work of Yeomans, expanding and refining it to work in different contexts in any landscape. The following layers are in order of permanence: infrastructure and development layers first, including Water, Access, Forestry, Buildings, Fencing, and Energy.

Water comes before Access in this order. That means we consider natural water flows before we decide where and how to build our roads. Every situation is different, but this sequence keeps us from forcing preferences that ignore the landscape.

Planning Roads to Align with Natural Water Flows

We often fail to think of roads as a water feature. But it decidedly is one. In Keyline design, roads should align with natural water flows rather than cut across them in straight lines that create problems during rain.

By planning access roads with the Scale of Permanence in mind, we can build them to work with the flow of water and help push it where we want it, with minimal erosion. This prevents the incision that happens when water cuts across or along a road the wrong way. The best designs take the complete context into account before the blade starts cutting up the landscape.

The Outcomes for a Resilient Landscape

When we design roads as water features using the Scale of Permanence and Keyline, we work in harmony with what we're given instead of against it. Few of us can start with a clean slate, but we can all start somewhere by changing the way we do things.

This approach can result in a much more resilient landscape, greater production, higher carrying capacities, and healthier animals. The healthier landscape tends to smooth out the highs and lows of weather as it adapts the land to take the greatest advantage of the climate.