Water Wise Permaculture - Tour/Class This Sunday!

Here comes the rain, and finally! A full .1 inches for the week! (as of this writing) Of course, most traditional garden vegetables require 1 inch per week, but at least it's something.

 

So far this year, the unseasonal heat and unusual dry have had us gardeners in S.W. Michigan working over time keeping their plants watered and wilt-free. 

And yet, 90% of our garden has received no irrigation this year. We have yet to water any of our established forest garden or hedgerow areas. The small amount of irrigation we have done has mostly come from collected rain water and recycled water. 

And that's because we've relied on a full set of stacked redundant tools and Permaculture strategies to create a water-wise garden, starting with an overall site water managememt design. 

And while these strategies are fully "research-based," tested and reliably proven, they are very different from the watering and irrigation strategies promoted by most conventional agriculture/horticulture. 

Because, while many of those "flashy" irrigation systems look impressive, in the real world, analysis of industrial-style irrigation systems has often found that results don't live up to predictions, especially when overall societal costs and impact is taken into consideration. Industrial irrigation depletes aquifers, salts soils, causes soil depletion, and contributes to polluting water ways. Assessments of overall societal Return On Investment (ROI) make it difficult to demonstrate a positive value for irrigation systems. http://www.iwmi.cgiar.org/assessment/files_new/research_projects/CASocioeconomicImpacts_Intizar.pdf

But even without taking into consideration broader societal sustainability, analysis of micro-level ROI for gardeners and farmers has been difficult to positively document, with University studies finding it difficult to recommend industrial irrigation systems. Even highly efficient drip irrigation systems improved profitability by only $7/acre. Sub-surface irrigation, the Rolls Royce of irrigation systems, increased profitability by over $150/acre, but costs, maintenance, and installation were considered to be prohibitive. The costs to anything other than a massive operation simply aren't worth the fuss! And just wait until one of these systems has a problem, which could easily erase years of profitability. 

http://www.sjrwmd.com/technicalreports/pdfs/SP/SJ97-SP9.pdf

It is possible to design very specific drip and soaker irrigation for select crop systems, as part of a whole water-wise design, that are useful, cost-effective, and save time, but as the research indicates, it requires some thoughtful analysis and design. 

Meanwhile, Permaculture offers a suite of water-wise gardening tools that can are low-cost, easy to implement and maintain, and have a proven ROI. Some of them are arguably free, and actually save time! 

These strategies include things like deep mulching, gardening in permanent ground covers, contouring garden beds to catch and store their own water, and managing overall site water resources to get the water to where the plants need it most. 

All of these strategies like mulching and bed design are "holistic" and "stack functions." For example, mulching improves watering, but also fertility, weeding and pest control, so they have compounded benefits, gaining us a higher return, with a lower investment. 

According to Cornell, gardens with just a few inches of mulch have been documented to require half the water, 2/3rds less time weeding, and create 8 - 13 degrees cooler soil temperatures. http://www.gardening.cornell.edu/factsheets/mulch/mulchland.html

Which is why Bill Mollison famously quipped: if you take the money you were planning to use on irrigation and put into mulch instead, you'll get twice as far and be happier for it, too." Of course, we can even grow our own mulches, making it a free option. 

Meanwhile, 4 inches of organic mulch has been found to be as effective as 1 inch of compost for building soil, and building good soil with lots of organic matter is another great water-wise strategy. A 1% increase in soil organic matter can make your watering go further, increasing plant-available moisture between 25 - 44%, turning an inch of rain into 1.44 inches. In one study, this decreased irrigation from 48 seasonal waterings to 36. Each additional percent of organic matter had a similar effect! 

https://www.northernwater.org/docs/WaterConservation/ConservationGardens/DeveloingDroughtResist.pdf

And while saving water and time are valuable in themselves, these Permaculture strategies improve produce quality, too. Rather than simply supplying the minimal plant water requirements as drip irrigation does, these strategies regulate soil moisture, which has a significant effect on the quality of a lot of produce, including tomatoes and peppers, which can get blossom-end rot from inconsistent soil moisture, leafy greens which will bolt in hot dry soils, and many root vegetables that can become woody without consistent moisture. 

If you're interested in learning a whole suite of Permaculture strategies for water-wise gardening, we'll be offering a class this Sunday at 9:00 am. We'll cover perspectives including Bill Mollison, Rosemarry Morrow, Toby Hemmeway and Geoff Lawton. We'll discuss Permaculture's "5 fold path" to water, compare various "water storage" systems by effectiveness and ROI, and share the simple equations that can help us decide the right size for swales, rain gardens, and water barrels. We'll also tour our gardens and see how we implemented these strategies here. And we'll even share some resources on water-saving and recycling, and grey-water systems. Suggested donation, $25. 

Introduction video: https://www.facebook.com/l.php?u=https%3A%2F%2Fm.youtube.com%2Fwatch%3Fv%3DGOXhuHsH9WA&h=zAQHnx2zd&enc=AZMxJGSpmrJTn8YCTzhY8LviAQmio8bDmU-qkmUyscyC2CnLbnmfQ8xbbM-AqnlbNoew4kjHe399Q9fBVF_aqKxQ495sFqskq1x7dDF05Xnmcq9QkWIItyAz7WORa5hVvvlMbmeX8lgw_5tMquJFqN1_Vc7zG6_lKaCYkcG_Na1Vyg&s=1

Space limited, to register, contact Mike, at lillie.house.kzoo@gmail.com. 

Gee, that's Swale! Resources for Permaculture Swales in Michigan

"Swales" are one of the most common water-harvesting devices used by Permaculturists. 

Like most Permaculture techniques, the use of swales is extremely site-specific, so I'd like to give a few tips and thoughts about using them in my biome, the Great Lakes region. If you aren't already familar with swales, here's a great "basic" introdcution from PRI: http://permaculturenews.org/2012/05/16/swales-the-permaculture-element-that-really-holds-water/

(Water-harvesting micro-swale/ditch system at Lillie House)

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The impact of swales can be nearly miraculous, especially in dry, wet tropical or Mediterranean climates where rain comes infrequently in large events and run-off is a big problem. But, as respected Permaculture teacher Patrick Whitefield points out, they might not always be appropriate: 

http://patrickwhitefield.co.uk/one-permacultures-holy-cows-death-swale/

In the Great Lakes region, we get most of our precipitation in the Fall and Spring, though we're lucky to get ample water through most of our growing seasons. Our relatively short growing season means there's a large advantage to having well-drained garden beds that warm up quicky and can be planted early in the season. Some areas in our biome may also have mucky clay soils that get easily water-logged. So a few indicators you might want to include swales in your design would be:

1. You have to deal with excess water from hardscape features such as a roof. 

2. You're on a slope and you know you have a problem with erosion or losing water to run-off. 

3. You want to establish a tree-based system like a food forest or orchard. 

4. You have a lot of land to deal with and you need to collect water from a large area using "extensive" methods that are easy to implement. 

Some counter-indications might be: 

1. You already have trees where you want swales. 

2. You have mucky soils and already expereince problems with draining. (Though in some special cases swales could actually improve drainage.)

3. You have a very steep slope or no slope. 

4. You only have a small area to work with (as we'll see when we do the math below, a swale will be a better tool if you have a collection area of least 20 feet or more.) 

If swales don't seem to make sense, there are other means of water collection and infiltration, such as ponds, "passive swales" (wood debris gabions layed on controur,) infiltration basins, keyline plowing, wicking beds, etc. For example, at Lillie House we use a network of a wide variety of tools to intensively manage water on our urban site. 

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Once you've decided to use swales, put some thought and planning into their design. Poorly designed swales do more harm than good. Make sure you get the size right. I have seen swales "blow out" because they were too small for the water they're meant to handle. These "swales" do the opposite of the Permaculture water mantra: slow it down, spread it out, infilltrate it--they actually concentrate water and direct it, possibly right towards your basement or favorite crop! 

On the other hand, I've seen swales that were too large, completely destroying the landscape hydrology and infiltrating water so deeply that no plant will ever have a chance at getting to it. Over-sized swales can also be a trip hazard and a danger to humans and wildlife passing through the garden. I know of a whole set of swales right next to sidewalks where kids live and play, that look like 3-foot deep death pits. These were installed by a "professional landscaper," positioned where they'll only ever get about a gallon of water in a major rain, but are super-sized to hold hundreds of gallons at once! I've even seen some "swales" dug below the water table, becoming permanent ponds. 

Worst of all, I've seen a few projects (in person, and AT LEAST a dozen more online) where folks dug deep swales right through established forest they intended to keep, needlessly wasting energy and harming the forest floor and roots of their trees to no benefit at all, as established forests in our region are reliably as good at harvesting and infiltrating water and stopping erosion as a swale!    

To size your swales, there are several tools that can help you out. University extentions often have recommendations specific to their regions on sizing rain gardens, which essentially perform the same function of catching water and infiltrating it. 

For most people, the rain-garden alliance is a good place to start: http://raingardenalliance.org/right/slope

Their tools will let you play around with your soil type, slope and catchment area. For example, assuming a clay loam soil, and a spacing of 20' between swales, it suggested a volume of 7.2 cubic feet per linear foot, or about 1,5' deep and 4' wide. On sandy soil, it recommended much smaller swales, just 3 cubic feet of volume.

(The basic math is pretty simple to figure out if you want to do it yourself. You need to know the size of your catchment area (in square feet) multipled by .6 will tell you how many gallons of water you'll collect for each inch of rain you receive. Next you'll need to test the infilltration rate of your soil. These two pieces of information will tell you how much water your swale needs to hold. Finally, 1.3 cubic feet will hold 10 gallons of water.) 

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This set of rotted wood swales is fed by our downspout and is planted with water-loving plants including Marshmallow and Valerian. In heavy rains, water cascades down the side of this system and into another set of swales. 

In our small-sale urban environment, with sandy soils, these little swales are hardly noticeable during the growing season, yet they're just the right size for the job. Though they looked small at first, I have never seen them be over-burdened, even in the heaviest rains.