The History of Rainwater Harvesting

When you consider the range of high tech rain harvesting equipment available today - from specialty diverters that remove debris from the water before it reaches the tank, to the high strength resin tanks that can hold hundreds or thousands of gallons, to powerful electric pumps that put the water right where we need it - it’s tempting to think of rain harvesting as something new. But in fact, capturing and storing rainwater in cisterns goes back thousands of years - to the neolithic age, when waterproof lime plaster cisterns were built into the floors of homes in Southeast Asia. 

By 4000 bce, rainwater storage tanks were a crucial component of the emerging water management techniques used in dry-land farming.

Ancient cisterns have been discovered in Israel, including one dating to around 2500 bce with a storage capacity of 60,000 cubic feet. It had been carved from solid rock, and lined with large stones sealed with clay to ensure it stayed watertight.

During the Minoan period (2,600 - 1,100 bce) large cisterns were used on the island of Crete to collect and store rainwater, including one at Myrtos-Pyrgos dating from 1700 bce, with a capacity of over 2,400 cubic feet. 

Around 300 bce, farming communities in what is now Pakistan, Afghanistan, Iran, and India harvested rainwater for agriculture and other uses. Notable collection tanks in this region include the Shivaganga tank, which collected rainwater from the Brihadeeswarar temple in Indai, and the Vīrānam tank, which was 16 km long and had a capacity of 1,465,000,000 cubic feet.

Romans excelled in rainwater harvesting and built entire cities with the infrastructure to divert rainwater into large cisterns to be used for drinking, bathing, washing, irrigation, and livestock. In Pompeii, rooftop water storage cisterns were commonly used before construction of the aqueducts in the first century bce, and for centuries, Venice depended on rainwater harvesting, because the lagoon that surrounds the town is brackish and undrinkable.

The ancient residents of Venice built insulated collection wells that allowed water to percolate down specially designed stone flooring where it was filtered by a layer of sand, then collected at the bottom of the cistern. Later Venice imported water by boat from nearby rivers, but these storage tanks were vital for times when the city was under siege by an enemy and cut off from the mainland. 

The enormous Sunken Palace cistern, in modern day Istanbul, was made to capture rainwater from the streets above, and still exists today. It’s so large that boats can sail in it.

In the 16th century, the terms ‘soft’ and ‘hard’ water were coined by early settlers of North America, who began to use rainwater for laundry instead of mineral-rich ‘hard’ water. When they washed with ‘hard’ water, the soap would react, causing a build-up to occur, unlike when they used soft rainwater, The harvested rainwater allowed the soap and dirt to wash off much more easily than the hard water, which reacted with the soap, causing build-up.

In fact rainwater harvesting was so important in certain frontier areas, that both settlers and natives would not have been able to survive without it.

How to Use the AHS Heat Zone Map

Most growers’s have some notion of the cold hardiness zones and what they mean. Thanks to cold hardiness zone map, for example, we know that a tropical variety that might survive winter Tampa won’t stand a chance in West Virginia.  But have you ever considered how much heat a plant variety can tolerate before deciding to grow it? 

While extreme cold can kill a plant overnight, death from extreme heat is gradual and can take much longer - sometimes years. Signs of heat damage can appear in various parts of the plant ; buds wither up, leaves fade to brown or white as their chlorophyll drains away, and leaves shrivel and become the target of insect attacks. A plant stunted from heat damage may even survive in a chlorotic state for several years, but when atrophy reaches a certain point, growth enzymes are deactivated and the plant dies.

Use the Heat Zone Map the same way you use the Cold Hardiness Map : locate the zone you live in and use that number code when selecting plants. The the map’s twelve zones show the average number of days each year that a region experiences temperatures over 86 degrees - called ‘Heat Days’. This is the temperature at which plants begin to suffer damage from heat. The zones range from Zone 1 (less than one heat day) to Zone 12 (more than 210 heat days).

Many plant varieties have now been coded for heat tolerance - the same way they’ve been assigned a cold hardiness zone that indicates tolerance for cold. Eventually the heat zone designations will be paired with cold hardiness zone designations in garden catalogs, nurseries, and reference books. The first two of the four numbers assigned to each plant variety indicate the cold hardiness zone, while the last two indicate the heat zone. So for example, a plant listed as 3-9, 8-2 could be safely planted outdoors year round in zone 7. 

Just remember that the heat zone ratings assume that a plant’s roots have received an adequate supply of water, and even a short period of drought can distort the accuracy of the coding system. Certainly some varieties are more drought resistant than others, no plant can survive becoming completely dehydrated. Herbaceous plants are about 85% water and woody plants are about 50% water, and it’s essential that plant tissues contain enough water to carry out photosynthesis. 

Juliette Lane's U-Shaped Kitchen Garden

Juliette Lane’s new home adds grace and charm to an already beautiful Myers Park street, lined with towering oak trees. It’s apparent that every detail on the property was carefully considered, from the very placement of the home and its color palette, to the careful design and arrangement of landscape plantings. And while an organic garden may not have been in the original landscape design drawing, with the simple relocation of a few shrubs, we opened up a level, south-facing area right beside the detached garage. In fact it was a perfect location for a organic garden ; lots of sun, close to the kitchen and just a few feet away from a water supply. Plus the white painted brick wall behind the garden will absorb heat during the day and radiate it back onto the plants on cold nights, creating a ‘microclimate’ that can warm the air around the plants several degrees.  

To maximize growing space within the area, we built Juliette’s Kitchen Garden in a U-shape - 3’ wide, 9’ across the back and 6’ on each side. The garden is 18” tall - the typical height of a chair seat or bench. This makes gardening much more comfortable, and also helps keep out rabbits.

Our Kitchen Garden design is made with rough sawn red cedar, which shows the rugged, unique texture of hand milled lumber. Untreated red cedar is naturally resistant to deterioration from moisture and insects, which makes it the ideal choice for outdoor projects involving cultivation, like raised beds, chicken coops, compost bins and greenhouses. 

We filled the garden with an OMRI listed soil blend of pine bark fines, mushroom compost and Sta-Lite PermaTill. These small pieces of slate have been heated and expanded in a kiln, and they help increase soil quality in raised beds by improving drainage and aeration. Once the garden is completely filled with soil, we mix in a generous amount of Espoma Plant-Tone - the gold standard of organic amendments for many years.

Simple, Savory, Sautéed Leafy Greens

Sure, there are plenty of clever ways to prepare leafy greens like kale, chard and collards, but sometimes simple and fast is what the situation calls for. Here’s a timeless and tasty recipe for cooking almost any leafy green variety, that will help put dinner on the table faster and with less fuss.

3 lbs kale, chard, or other leafy green

4 garlic cloves, coarsely chopped

4 tbsp olive oil

3 tablespoons red wine vinegar

Strip the leaves from the stems, and cut away any tough midribs in the leaves. Coarsely chop the greens, and rinse & drain thoroughly. 

Heat the oil in a large pot over medium high heat.  Add the greens to the pot, stirring frequently so that they’re evenly cooked. After softening the greens for about a minute, season them with salt , stir in the garlic, and cover. After just a few minutes - once all of the greens have wilted down -  remove from heat, stir in the vinegar and serve.

For a fast and easy meal, prepare some pasta while you sauté the leafy greens, and toss them together, along with a little more olive oil and a ladleful of pasta water.

Calculate Your Potential Rain Harvest

There are plenty of good reasons to catch and store rainwater, and people have been doing it for thousands of years. But have you ever wondered just how much water flows down your home’s roof when it rains?  Well, you could flex those grade school mathematics skills and make the computation based on the size of your house and amount of rainfall. Or you could click here to use a simple automatic rain harvesting calculator courtesy of North American Rain Systems. Happy Harvesting!