Here are my highly personal notes on Chapter Ten: Water From Another Time in Peter Bane’s The Permaculture Handbook (2012). Any misrepresentations of Bane’s words or work are mine alone and completely unintentional. Notes on each chapter linked here.
“Aquaculture is of growing importance worldwide to supplement static or declining supplies of wild-caught fish. This trend will only accelerate. The small farm would do well to develop some aquatic systems for yield. Some easy crops to grow on a small scale include water chestnut (Eleocharis dulcis) and watercress (Nasturtium officinale). A small kiddy pool of four-foot diameter is sufficient for a small crop, which can be fertilized periodically with a little urine. Yields of water chestnut can reach 0.4 lb per square foot. It can
also be grown in combination with channel catfish, the health and yield of which it seems to improve” — Peter Bane
An eighth of an acre of garden (5,500 square feet) needs 3,000 gallons of water per week in the growing season.
We need to have two or more good sources of water and the ability to conserve and reuse it: “Water we fail to collect and water we use and release all returns to soil and streams. To drought-proof our landscapes we must develop the soil as a water storage by building up its carbon content.” But water in soil isn’t available for things like drinking, washing, fire control, etc; for that, we need fluid water in tanks and ponds.
Well water that needs to be pumped is the least resilient of all water sources, because it depends on electricity; it’s “only our access to cheap fossil fuels [that] enables us to pump huge volumes of water today (roughly half of U.S. cities are supplied from wells), but agriculture dependent on deep wells is a doomed proposition.” Water tables are falling, ground water is polluted (Bane mentions fracking here).
Rainwater catchment should be the primary source of water except maybe for large properties in the arid West. Catch, concentrate, filter, store securely, release. Don’t drink the water from galvanised roofs, or roofs with galvanized nails, though (they have zinc, which can be toxic when concentrated). Best roofs for drinking water are metal, clay or concrete tile, wooden shakes, or sod. Grit from asphalt roofs can be filtered. Need 20 feet or more between roof and large tree canopies if you’re collecting roofwater (to keep waste materials from insects, small mammals, and birds from landing in it). Divert the first few gallons of rain away, because it’s debris-laden (it’s just cleaned the roof); you can buy a first-flush diverter or make one. Bane discusses at some length the materials and designs of water tanks from rain barrels to large storage tanks.
Store it high. Release it clean. Match quality to purpose. Slow the flow (with swales, dams, etc) and follow the wave.
Water’s function in a landscape: Hydrate soil; generate energy; pond for microclimate buffer; recreational pool/pond; livestock water; human water; irrigate crops; aquaculture; wildlife habitat.
Calculating runoff (p. 163): 5/8 roof area (in square feet) x depth of rain (in inches) = gallons of runoff.
The water cascade [Several of these seem like they’re saying the same thing in different words?]:
Discarded tap water: Water lost when getting a shower hot can be used to all washing purposes. If it has soap in it, it can be used for handwashing, bathroom cleaning, laundry, toilet flushing.
Bathwater: Warm and a little sudsy, can be used for hand cleaning clothes or prewashing clothes (“just throw them in the bathtub before you get out, stomp around a little, and rinse later”).
Laundry water: There’s lots of it, with some soap, soil, and trace amounts of body wastes. Use it to water trees, fruit crops, lawns, ornamentals.
Dishwater: Use for spot watering of gardens, flushing toilets.
Shower Water: Put a bucket under the tap while the shower is warming up. Use it for flushing the toilet or cleaning the shower.
Greywater: Water from sinks, showers, dishwashers, laundry. Most of it can be used on the landscape. “Greywater should not be exposed to human contact more than 12 hours after initial use.”
There’s a section on wastewater treatment and filtering, another on using water economically.
Aquaculture: Rice-fish-duck polyculture. Water chestnuts, water cress. p. 173. Suggestions for improving pond yield. p. 174-75. Plus a list of about 25 aquatic species (fish) for ponds.
I skimmed a lot of this chapter. There are more photos and sketches in this chapter than in most of the others.
Featured image (top image) is a crawdad in an aquarium in the Montshire Museum in Norwich, VT, March 2017. You could grow them for food.