Surface Runoff

The most unknown and underappreciated infrastructure at "Polyface Central" (what we call the home farm as opposed to nearby rental properties) is the 12 miles of buried 1 1/4 inch water line along the edges of our fields.

At today's prices, just the polyethylene pipe is $50,000 in value, not counting installation labor and pond construction.  

Ponds?  In many parts of the U.S., ponds are prohibited because they're deemed "hoarding" water.  If I inventory water on my property, it deprives others of that water, some say.

I'd like to explore that mentality with all of you, our loyal patrons, and share our convictions. You can decide which approach is most helpful for our neighbors, our ecology, and our Earth.

Many environmentalists have taken this position and lobbied state governments to criminalize pond building.  

To my knowledge, the worst two states are Colorado, which even bans rain barrels, and California, which prohibits digging anything bigger than a bathtub.

Landscape water, or what I'd call nature's hydrologic inventory, comes in many forms:  underground aquifers, waterways (creeks, streams, rivers), and natural springs.  

These are all part of the commons,  enjoying shared ownership since no single person or land manager put them there.  These commons sources originate somewhere, traverse a property, and then exit to somewhere else.

Furthermore, these commons are finite.  An aquifer holds only so much water in sand pits and caverns underground.  

Wells punch into this inventory and suck water out.  

Springs only generate a certain amount of flow.  Ditto for rivers and streams.  

You can measure the flow of a river.  

In all of these, if enough people suck water out, they cease to exist.  

One of the biggest river systems in the world is the Murray-Darling in southern Australia; in the 1800s, ocean-going steamships sailed 500 miles inland on this magnificent river.  Today, it doesn't even make it to the ocean because farmers and cities draw from it along its course and finally eliminate it.

In the 1930s, an Australian mining engineer named P.A. Yeomans, looking at the dry Australian landscape, took a revolutionary view.  He dared to think of surface runoff as completely different than the commons.  

His thinking greatly impacted Bill Mollison and David Holmgren, fellow Australians, who in the late 1960s developed Permaculture.  

American novelist and farmer Louis Bromfield at his Ohio Malabar Farm copied this thinking by building a series of small ponds that he admonished other farmers to duplicate to eliminate flooding on the Ohio and Mississippi Rivers.

That's a tall order, to be sure, but here is the rationale.  

Roughly one-third of all raindrops arrive either too fast or too much (or both) to be absorbed by the soil.  This is a global reality regardless of climate.  In a given year, the average landscape, whether used for agriculture or wasteland, absorbs two-thirds of its rainfall.  The other one-third becomes surface runoff; in many cases, this generates a flood.

The point is that those one-third of raindrops do not benefit where they land and don't benefit where they go.  They can become catastrophic if too many join together downstream.  Every flood is an accumulation of surface runoff.

By categorizing surface runoff differently than commons water, we can devise a response plan to minimize the devastation caused by those escaping and cascading raindrops.  The answer is ponds to catch surface runoff.  At Polyface, we've built more than 20 ponds for precisely this service.  These don't impede creeks and rivers; they simply hold surface runoff.

A bone-dry valley in July might collect enough surface runoff from a snow melt in January to fill a 3-inch pipe for several days.  That's a lot of water.  

One valley flowing into another into another and collecting into a stream, eventuates into a destructive torrent.  

To get an idea of how much water we're talking about, in our Shenandoah Valley of Virginia, we receive 30 inches of rainfall a year.  One-third of that is 10 inches.

One acre-inch (one inch covering one acre, which is roughly a football field without the end zones) is 30,000 gallons; 10 inches is 300,000 gallons.  That means each acre we own at Polyface Central generates about 300,000 gallons of surface runoff water per year.  

We own nearly 1,000 acres, which translates to 300,000,000 gallons.  That's just our farm.  Add the neighbors, and you can see these numbers become astronomical.

Pre-European, North America was roughly 8 percent water due to beaver dams (ponds).  Today, we're below 4 percent water.  All those dams created protections from flooding.  They served multiple purposes: reducing volume and velocity in a flood, catching silt from any soil being washed away; wildlife nesting and watering availability; evapotranspiration encouragement for healthy cloud formation, and overall hydrologic function.

One of the core Permaculture principles is that every raindrop should stay as close to where it falls for as long as possible.  Slowing down gravitational raindrop flow is an overarching goal of redemptive landscape design.  

This is one area where human ingenuity and mechanical prowess can massage the landscape into far better function than original landforms.  

A "no touch" policy that exists in too many areas, like wilderness areas and other government-owned land, is not a recipe for ecological enhancement.  The beavers aren't coming back 200 million strong.

But with strategic excavation and judicious design, we can build hydrologic redemption into the landscape, hydrating it for dry times and protecting downstream neighbors from catastrophic flooding.  

Yeomans challenged farmers with two notions: eliminate surface runoff and never end a drought with a full pond.  In other words, catch those escaping raindrops and then apply them to parched soil during dry times.

Writing and designing before the advent of cheap polyethylene pipe, his systems all depended on off-contour ditches, or swales, to duct the water from the pond out to farm fields.  

I had the privilege of visiting one of his farms in Australia about 25 years ago, and the genius was clear to see.  

Today, with pipe and extremely efficient pumps, we can move water uphill without excavating gentle ditches.  The concept is the same and the benefits identical. Yeomans' book Water for Every Farm is still the go-to classic in innovative thinking about water on farms.

Imagine if this concept were implemented on the nation's interstate system.  Instead of cutting ridges and filling valleys, placing culverts in the bottom to drain water away, each of those valley fills could be a pond dam.  Moving the culvert to the top of the fill still offers drainage, but with the same amount of earth moving, you get a pond for your effort instead of a dry valley.  

All along the interstate, ponds would offer flyways for birds, flood control for the landscape, and irrigation options for farmland.  That's called redemptive land care.

At Polyface, we've been investing in ponds for decades and intend to continue doing so until we reach that magnificent beaver number:  8 percent.  We're not even at 1 percent yet, so we have a few lifetimes to go.  

Thank you for taking the journey with us. Your participation in our land mission enables our healing hands to caress the landscape.  

Joel