Water Harvesting for Drylands and Beyond Vol 2 Notes

• <UL> Introduction Chapter 1: Assessing Your Site, Choosing Your Earthworks, and Tips Chapter 2: Berms and Basins Chapter 3: Terraces Chapter 4: French Drains Chapter 5: Infiltration Basins Chapter 6: Imprinting Chapter 7: Mulching Chapter 8: Reducing Hardscape and Creating Permeable Paving Chapter 9: Diversion Swales Chapter 10: Check Dams Chapter 11: Vegetation Chapter 12: Greywater Harvesting Epilogue Appendix 1: Patterns of Water Flow and Erosion with their Potential Water-harvesting Response Appendix 2: bunyip water levels and A-frame levels Appendix 3: Water-harvesting earthworks calculations Appendix 4: Plant Lists and requirements for Tuscon, AZ Appendix 5: Sizing Kitchen Resource Drain (KRD) in Arizona Appendix 6: Resources References </UL>


• Preface


• Before and after santa cruize river pictures, 1900 and 2006 [Pdf pg 31]


• 16 billion acress of the world are dryland, 47.2% of Earth's land, 20% of the world lives in drylands


• Introduction


• 1" of rainfall = 0.623 gallons per square foot catchment surface


• 10 mm of rainfall on 100 square meters of catchment = 1000 liters


• "When the Rivers Run Dry" by Fred Pearce = "Harvesting the rain was once a worldwide technology on which millions of people depended. Every locality had its own system. Almost everyone did it. " ^5


• Negev Desert in Israel, 100 mm annual rainfall, can grow dry-farmed pomegranates, almonds, figs, peaches, carob, and grapes. ^7


• Dryland fields that harvest rain typically yield 2-7 times more than those that do no ^8


• Mosquitoes need 3 days in standing water, proper earthworks will drain away into the soil within 12 hours, and typically not more than 1


• Automatic timer watering: irrigation uses 47% more than by hand, drip irrigation uses 16% more,


• ~30% of potable water in US single family residence is used for outdoor irrigation ^12


• hot dry climates can be worse, Albuquerque NM 40% goes to irrigation^13, San Diego/Denver/Phoenix use over 50% ^14


• by harvesting rainwater for landscapes could reduce total potable water consumption 30-50%


• typical indoor use 30% of potable water for flushing toilets,


• the animals supported by the land by weight are less than the weight of the worms, bacteria, fungi, and other soil creatures. [by putting water into the landscape, you increase its carrying capacity, the more life IN the soil, the more life can be supported on the soil.]


• Fig I.5, soil pyramid,


• more organic matter in soil holds more water, less than 1% OM is bad, 2%+ can require up to 75% less irrigation


• shade soil with mulch or plants, can reduce evaporation by 60%+ ^19


• irrigation leads to salt buildup, 25 million acres of farmland around the world become lost to salt annually ^22


• Michael Evenari in Negev Israel, found rain harvesting fields decreased salinity over time to the point where they could grow moderately salt sensitive plants like apricots, almonds, and carob ^23


• fig I.9/10 same place in India one with salt one without [pdf 50]


• 1930s Civil Conservation Corps projects


• 5% of the electricity consumed in the US is used to move water ^25


• no need for synthetic fertilizers, pesticides, herbicides, and green waste hauling when water is harvested and on-site nutrients recycled


• "The Weather Makers" say 55% of US domestic energy is used in heating/cooling homes, costs $44 bil


• Thar desert, world's most populated, village of Laporiya, Project in Alwar District of Rajasthan, 5 dry rivers revived perennial water flow after 650 villages build 3000 small earthen check dams and implemented a community-led forestry project tto "responge" the watershed,


• Chapter 1: Assessing Your Site, Choosing Your Earthworks, and Tips


• "Food from Dryland Gardens" by David Cleveland and Daniela Soleri


• Table 1.1 Guide to Water-Harvesting Earthworks [pdf 70-71]


• termites, earthworms of the drylands


• Chapter 2: Berms and Basins


• make the base of the berm 4 times the height on average, measured from the bottom of the basin


• sandy soil needs thicker, while clay soil can be a little thinner


• many small berm and basins spread out (in desert) for drought-tolerant plants, a few larger berm and basins for thirsty exotics, Concentrate the water or spread it out, still capture the same amount


• build to hold a large storm's rain, 2-3 inches in Tuscon AZ


• Box 2.2[pdf 99] to find volume of water a berm and basin will hold: VOLUME = 0.5 x WIDTH x DEPTH x LENGTH VOLUME x 7.48 gal/ft^3 = gallons


• Box 2.3 spacing distance, runoff coefficients [pdf 100] Impervious paving/roof: 0.85-0.95 Healthy Sonoran Desert uplands: 0.20-0.70 (avg 0.30-0.50) Bare earth: 0.20-0.75 (avg 0.35-0.55) Grass/lawn: 0.05-0.35 (avg 0.10-0.25)


• sandy soils have lower runoff coefficient while clay soils have higher


• SPACING DISTANCE = WATER HOLDING CAPACITY of berm and basin / (RUNOFF COEFFICIENT x RAINFALL)


• Walk on your berms while you check their level with a bunyip/A frame, tamping down by foot is all that is required, if berms are to be used as a road or path mechanical tamping may be required


• Basins are never tamped, cover them with mulch


• can stabilize the downside of a berm with rocks placed close together, careful not to create erosion points between rocks where water flow concentrates,


• plant vegetation around spillways


• spillways should be 1/3 the height of the berm, a 12" berm should have the spillway set 4" lower than the top pf the berm,


• spillway should be twice as wide as the berm is tall,


• brush berms, stakes and brush [pdf 109] fig 2.26


• fire resistant vegetation, salt-brush (Atriplex), Thronless nopal cactus (Opuntia ficus-indica), Aloe (Aloe) can be planted on berms to provide a fire break


• log erosion barriers, fell trees perpendicular to slopes, cut and place branches on upside of log, cover with straw/mulch


• windberms


• Chapter 3: Terraces


• high upfront energy construction, earthen walls, stone wall, masonry wall.


• can be catastrophic when they fail, so only use on the small scale w/o experienced builder or engineer


• suited for 10-18 degree slopes (18-33%), in some places as much as 22 degrees (40%).


• not good on clay soils, sub-clay can cause saturated topsoil to slide,


• start at bottom and work up, level working surface, stabilize base,


• height of wall should not be more than twice the depth cut into the earth (fig 3.5)


• width of terrace = maximum depth of cut in soil / degree of slope


• topsoil will settle/compact more, make sure to keep subsoil as the base


• 12-20" thick walls for less than 2 ft walls, 20-24" for walls 2-4 ft


• dry stacked walls less than 2 ft should have batter of 5-10 degrees, dry stacked walls 2-4 ft should have a batter of 15 degrees


• "Earthship Volume 3" by Michael Reynolds for tire retaining walls


• "The art and craft of stonescaping: setting and stacking" by David Reed, comprehensive and photos


• berm on edge to keep water in the terrace, spillway ½ height of the berm, 10" berm with 5" spillway is good, no need for more than 5" flooding the terrace, spillway should be at least twice as wide as the berm is tall,


• Paul Trawick "Trick;e-down Theory, Andead Style: Traditional Irrigation Practices Provide a Lesson in Sahring" Natural History Oct 2002 pg 60-65 and his book "The Struggle for Water in Peru"


• trinchera is Spanish for stone-wall reinforced terraces OR check dams, used in Sierra Madre MX by Tarahumara Indians


• www.growingvinestreet.org - Seattle street


• Chapter 4: French Drains


• landscape fabric around perforated pipe to keep roots out, infiltration chambers to keep roots "out", old waste buried to create subsurface flow,


• fill with gravel to harvest rain in high foot traffic areas, no tripping hazard


• low sediment in captured water or else it will eventually fill, good for roof/paving runoff,


• build level or on contour to infiltrate water there, slope to move it away (from a foundation w/ pipes),


• as with other water harvesting earthworks keep it at least 3 m / 10 ft from foundations,


• make at least 15" x 15" and whatever length you need for the amount of runoff,


• cardboard, a few layers of newspaper, or magazines on the bottom of the drain w/o a pipe can spread the water more towards the sides, keeping more in the upper 2' versus saturating the area just below the drain. -Richard Jennings of Earthwrights Designs


• perforated pipe should be placed level to allow even infiltration,


• no more than 24" deep is best,


• angular, 0.5-1" gravel, pumice, basalt,


• ½ pipe, bottom open will prevent roots from clogging (see fig 12.12), better than perforated, does not need landscape fabric and can be used with native soil instead of gravel, infiltration chambers, inspection port?,


• don't plant directly ontop of french drains b/c the plant's weight will collapse the drain, plant around it,


• David Bainbridge "A Guide for Desert and Dryland Restoration"


• deep pipe irrigation drive pipe vertically into soil to water lower and encourage root growth deeper, pvc, bamboo, rock-tube, 18-24" (45-60 cm) lengths of 0.75-2.0" (20-50 mm) diameter, drill holes ever 3" (7 cm) [fig 4.11, pdf 143] once plants are established the irrigation pipes can be removed


• Chapter 5: Infiltration Basins


• works best on flat or gradual slopes


• use existing basins in desert re vegetation when possible


• excavated dirt can be used to build/improve raised paths


• 3 m away from foundations/buildings or drains, don't build on top of septic,


• be at least 9" deep, once mulch is added and breaks down/silts up over a few years it will fill, 18-24" is the high end for depth, deeper and the water may not infiltrate within ~12 hours (standing water)


• berms can be placed on the sides, on gradual slope, or terraced in slight slope, berms should be at least 60 cm wide


• basin should extend 1.5x the width of mature plant's canopy to give roots room to spread out,


• can have many small basins or 1 large basin, to break up for a path/etc, gives more even infiltration,


• Calculating basin capacity [pdf 153]


• adjust slope of basin walls as needed, but 3:1 is good for foot traffic areas


• bottom of basin should be as level as possible to spread infiltration


• in heavily compacted/poorly draining soil, the bottom of the basin may need ripped/aerated,


• have a spillway to drain the basin that points away from structures


• higher water needs/tolerance in bottom of basin, periodic inundation, velvet mesquite, canyon hackberry, blue palo verde, desert willow are S. AZ examples, Date palm


• less water requiring plants can be located on the inner slopes of the basin


• plant on 4-10" slightly sloping pedestals in the basin to prevent water from standing directly on the stem


• drought hardy plants on the very edges of basins, avocados, carob trees, edible nopal cactus (Opuntia ficus-indica)


• cold air will pool in basins, cold intolerant plants may need to be planted w/o a basin


• can harvest greywater in basins


• trees that should not be placed near houses b/c shallow or invasive roots: eucalyptus, cilean mesquites (prosopis chilensis), African Sumac (Rhus lancea), Cottonwoods (populus fremontii), pepper trees (Shinus spp.)


• desert ironwood (Olneya tesota)


• berms can for basins around existing vegetation, boomerang berms


• bury unfired clay/earthen pots as low tech irrigation, cover pot with flat rock/plate, similar function to a micro-basin, plant pots in basins also, big in India


• David A. Bainbridge reports buried pots are as much as 10x as efficient as surface drip irrigation ^6


• India study growing pumkins to maturity over 88 days with 2 cm of water / hectare ^7


• In Tuscon garden 1.5-2 gallon pots irrigate established oregano, sage, chives, marjoram, thyme, fennel, and lemon grass,, refill 2x weekly in summer, 1x weekly in winter


• Raingarden.org: "Gov studies have shown up to 70% of pollution in watercourses is carried by stormwater. . half this pollution comes from things we do in our yards/gardens" ^9


• Chapter 6: Imprinting


• numerous small, firm, depressions


• Bob Dixon, invented imprinting in 1976, worked with Ann Carr


• used on slopes up to 2:1 and annual rain ~3-14",


• more for large land scales, no cost effective for backyards, (bringing in heavy equipment)


• imprint rollers, bulldozer tracks, large hoofed animals,


• 'V' imprints work best,


• [compares it to disking, tilling, etc, but not chiseling/keyline plowing, seems inferior to keyline]


• imprints can be washed out by heavy rains, best used lower on sites after other water harvesting/control has slowed the water


• each imprint should hold ~1 gallon of water, be 30 cm apart, and be 10-18 cm deep x 25 cm long x 20 cm wide


• home-made community imprinter made in AZ used on 50k acres ^4


• Constructing a roller [pdf 175]


• seeding imprinted land: 25% pioneer, 75% hardy perennial; can add in barley/rye since it is cheap and plentiful, 10-15 lbs/ac of seed


• adding wheat bran to seed mix will keep the smaller seeds from congregating at the top, more uniform,


• buffelgrass (Pennistemum ciliare) exotic to SWUS


• commercial seeders often need a seed agitator when using mixed seeds,


• seed in the Sonoran Desert in fall to take advantage of milder winter rains not heavy summer rains that could erode imprints


• cool season germinating restoration plants: perennial four-wing saltbrush (Atriplex canesens), annual indian wheat (plantago purshii), Russian thistle (salsola iberica),


• fig 6.7 steep slope imprinter, bend outside imprinter angles from 45 to 65 degrees


• if soil is too compacted to imprint, wait until 1 week after a rain, if sandy wait until just before rains,


• imprinting psi 15-30


• stay off imprinted land until vegetation is established, no cattle, no ATV,


• Chapter 7: Mulching


• mulch on nitrogen rich (gass/manure/etc) on newspaper/cardboard (carbon)


• thin mulch on basins that don't receive much rain, don't want the mulch preventing the rain from reaching the soil, thicker mulch on basins that receive heavy water


• in drylands 4" of mulch on runoff harvesting earthworks, 2" on direct infiltration beds (no runoff coming in)


• keep mulch around the stem of trees reduced to 1/2" to prevent it from becoming too wet, same for cactus in desert, they can rot/disease so keep mulch away from base,


• can use more mulch in wetter regions, 8" in Connecticut


• 2" of gravel mulch max around plants, 6" w/o plants


• vertical mulching, dig a hole/trench 6-18" away from newly planted tree, 12-15" deep, 1-2' wide, 2-20' long, the long/lage holes/trenches can be used to "dispose" of large amounts of material [sort of like a french drain]


• Semi-arid India, mulched trenches 20 cm deep and 2 m apart gave 25 times more grain yield and 2 times more straw yield than those w/o in a very dry year ^3


• chickens and desert tortoise eat Bermuda grass


• 10 cm dry straw with chickens, eliminates odor [deep mulching], counters the nitrogen rich droppings,


• other plants for chickens: wolfberry (Lycium spp.), desert hackberry (Celtis spinosa), edible cacti, barberry (Berberis trifoliolata), pomegranate (Punica granatum), quailbush (Atriplex lentiformis)


• 8" of mulch around a tree lets the tree be used as a urinal, same idea as the deep mulched chicken beds, Swedish study: adults produce enough fertilizer in urine to grow 50-100% of the food required by an adult ^5


• Hohokam of Southern AZ lived before 1400AD and mulched their agave with rocks, 29" high and 1.5 m in diameter


• Study: Suzanne and Paul Fish, Charles Miksicek, John Madsen - "Prehistoric Agave Culticvation in Souther Arizona" : root biomass under these rock mulched beds is 2.7 times greater,


• rock mulch also prevented rodents from damaging agaves during dry times


• mulch with junk mail, plant 2-6 cubic feet of dense junk mail next to trees to act as a sponge, eventually breaks down to soil, but by then the tree is established and no longer needs a sponge


• video: "Ruth Stout's Garden"


• Chapter 8: Reducing Hardscape and Creating Permeable Paving


• pavement covers 60k sq miles / 2% of the surface area of USA, 10% of all arable land - www.culturechange.org/factsheet1.html


• 10-20% impervious hard-scape will start to show significant stress. ^2


• exposed cement/buildings/parking lots/etc all absorb heat during the day and release it later leading to temperature increases as much as 10F, this is called Heat Island Effect ^5 [typical thermal storage]


• hard-scape runoff can be used to funnel water to catchment areas, [like swales beside roads, planted]


• two-track driveway paves 60% less than a conventional driveway


• traffic circles as catchments with vegetation [fig 8.5 pdf 204]


• slope pavement toward an earthwork/basin/landscape instead of to a drain


• open curbs to allow runoff into landscape/basin instead of to drains [fig 8.10 pdf 207]


• velvet mesquite (prosopis velutina)


• Porous Pavements ^23 by Bruce K Ferguson


• "pave" with gravel or rocks/bricks that leave spaces for water infiltration, use angular gravel b/c it has spaces between it while round gravel "seals" together


• in 1886 agricultural and urban development covered 10% of Des Plaines River watershed in Illinois and had a discharge rate of 4 cubic feet per second. Today 70-80% is covered by development and the discharge rate is 700-800 cubic feet per second. ^46


• Bruke K Ferguson "A porous pavemtn with little to no drainage structures is commonly less expensive than a dense pavement with large drainage systems" ^49


• better traction on porous pavement


• cut curbs to allow water to get into sidewalk basins where trees are planted, fig 8.34 [pdf 229]


• Chapter 9: Diversion Swales


• not on contour, divert water to other harvesting earthworks,


• can slow the erosive of culverts


• [discussed by Yeomans for transporting water between dams][hah, references Yeomans. Yeah, just read Yeomans' work]


• Ponds in drylands often evaporate quickly; better to store the water IN the soil


• deep ponds are better than wide ponds b/c less surface area to evaporate [in drylands]


• plant deep rooted trees around the pond to shade it


• stock pond with fish to eat mosquitoes


• can terminate diversion swales with other earthworks, ponds, reservoirs, cisterns


• treat as berm 'n basin [swale] generally, does not need to hold as much since the water flows,


• if slowing outflow from a culver, rule-of-thumb is to build the diversion swale 2-4 times as wide as the culvert's diameter,


• if you want maximum flow, don't plant [much] in the diversion swale to impede flow; plant beside


• can slow flow with periodic one rock high check dams


• surge basin = 12-18" deep pond used to diffuse the kinetic force of incoming water, good for arroyo and culverts


• Chapter 10: Check Dams


• permeable, gabions, placed within drainage, temporarily slows water does not stop it


• made of rocks, brush, straw bales, poles (coppice), concrete/urbanite,


• placed in eroding arroyos or gullies, capture detritus as well as slow water, near top of rills


• stabilize roads/paths crossing drainages (ephemeral [and otherwise])


• angular rocks lock better than rounded, at least 30-60 cm and 9 kg per rock, gabions can use smaller rocks but will fail once the wire rusts away, establish roots to replace wire


• Seep willow (Baccharis salicifolia) good in drier SW USA, use fresh cuttings in check dam construction and they will root, speeding stabilization


• Tamatisk (Tamarix ramosissima) good for building check dams


• the larger the poles/branches the better, 3-6" and 4-6' long


• straw bales are less permeable and more prone to blowouts, anchor well


• best in gradually sloping or naturally terraced areas, not good on steep slopes,


• can be placed on upslope of boulder or tree to help stabilize


• place upstream of a narrowing flow (slight pressure will pack in the dam), do not place in the narrow part or just after (more pressure)


• "An Introduction to Erosion Control" "Induced Meandering: A Method for Restoring Stability to Incised Storm Channels" "Let the Water do the Work" -Bill Zeedyk


• no taller than 60-90 cm, no taller than 1/3-1/2 the depth of the channel and the dam's center point


• many small instead of few large


• dig a trench to anchor the loose rock check dam into, depth should be ½ the height of the rocks you are using, cut into both the drain bed and the side banks, cast the dirt from the trench upstream to help with silt in


• set stones so they ramp the water up and over the chack dam, not channel it under, like shingles on a roof, fig 10.12A/B [pdf 263]


• gabions can be fabricated with woven-joint wire fence, welded joints breakdown faster


• apron should be 1.75 times the dam height, important b/c overflow will erode under the dam and collapse your work


• Apache Plume (Fallugia paradoxa), Seep Willow, Asparagus - can take droughts and inundation and sprout through newly collected silt/soil


• brush check dams, typically no higher than 1 m, last 3-5 years under unfavorable conditions, no anchor trench, no apron, quick to build, more maintenance,


• in low flow years the brush can slow water and accumulate sediment, in moderate flows it can do the same, in large flows the brush gives-way acting as a relief valve so it absorbs the erosive force instead of the banks, ^9


• Zuni builders (above) say once woody material is in the watercourse - "Mother nature will move it where she wants it."


• weave the brush together, stomp it into the channel, anchor it with whatever is available (drive in posts, existing outcroppings, rocks, etc)


• using brush from live plants that can root like: willow, poplar, apache plum, mulberry, seep willow


• Zuni use pungie posts, bundles of pinyon and juniper limbs stuck into an arroyo like a rake, pointing upstream to catch debris, should be placed downstream of brush check dam,


• start with a 3 straw bale wide test check dam first, do not use straw bales in large flow areas, bury straw bales 3/4 deep to anchor,


• check dams can be used as crossings by spreading out the flow and lessening the slope into and out of the gully. They can be an alternative to culverts that restrict and speed flow. If you are driving over it have it engineered properly.


• Fire can travel up drainages, planting California Poppy (Escholzia californica), agave, jojoba (Simmondsia chinensis), or pomegranate (Punica granatum) can help stop the spread of fire


• check dams can create wildlife habitat and corridors,


• El Coronado Ranch, Chiriahua Mtns SE AZ 6k ft, Joe and Valer Austin, 20k Check dams on 2k acres,


• check dams should be more banana shaped not flat topped to prevent end cutting,


• cattle spend less energy looking for food,


• Chapter 11: Vegetation


• plants anchor, build, and shelter soil - reducing erosion and controlling dust


• plants create a microclimate that supports soil microorganisms,


• plants provide wildlife habitat, food, fiber, forage, building materials, medicine, oxygen, water storage, beauty,


• plants are living pumps, pumping groundwater to the atmosphere via evapotranspiration and into the fruits we eat,


• shade trees can reduce summer temperatures 11C ^1


• earthworks MUST have vegetation or it will erode quickly


• place plants in microclimates, sheltered, sunny, cold air pools in low spots (early blooming plants near top of hill where cold air drains away; later blooming plants near bottom of hill), etc


• use porous windbreaks to slow evaporation, trellis, trees, vines, shrubs, evergreen is best winter wind break b/c they keep leaves


• can deflect or funnel air depending on the situation/season


• trees are the foundation vegetation, plan out your trees mature spacing and work from there, determine shadows, mircoclimates, etc,


• calculate water needs of plants vs. runoff


• AZ Dept of water resources': Low Water Use/Drought Toleratn Plant List


• 500 known edible plants in the Sonoran desert ^9


• plant several things and see what does best [Lawton has similar philosophy, you can always cut down a tree but you can't just add one in; always plant more than you will need], also guilds,


• velvet mesquite is key guild in Sonoran desert, under it live desert hackberry, greythorn, wolfberry, suguaro (grows above mesquite eventually), chiles, animals are attracted to flowers/seed pods, birds spread seeds, animal droppings build soil,


• Tim Murphy, "Hackberry/Walnut" guilds ^14


• time your planting correctly, late summer/early fall is often better for perennials than spring, plant around heat and rainfall


• "Effects of Planting Practices on Tree Performance" Jimmy L. Tipton, Elizabeth Davison, Juan Barba, Series P-107, University of Arizona Extension


• low water need plants will likely need supplemental watering for ~2 years while they establish


• 5-gallon buckets with a 3-4 mm hole near the bottom can be used as a cheap drip irrigation for about an hour, place it somewhat away from the base to train the roots out


• if plants get too dense, they use up your water budget, if plants are dropping/dieing back look into thinning them, [succession, pioneers fast and first also the first to be thinned, useful for helping establish the long term plants, chop and drop]


• 100 fruit trees planted throughout a community are just as productive as ones on a orchard farm,


• one big tree can provide oxygen for 4 people, 1 acrfe of forest absorbs 6 tons of CO2 and puts out 4 tons of Oxygen, annual needs for 6 people, Citizen Forester's Guide: The Simple Act of Planting a Tree ^22, 23


• 1985, American Forestry Association, 50 year old urban tree, $73 in air conditioning, $75 in soil erosion and storm-water control, $75 wildlife shelter, $50 air pollution ($273 in 1985), average lifetime value of a 50 year old tree = $57k ^26


• home values increase 7-20% with trees ^27


• Chapter 12: Greywater Harvesting


• evaporative cooling gives salty water


• www.OasisDesign.net


• use 3-way valve to landscape and sewer for residential retrofitting


• discharge greywater in the top 2' (on surface fine), mulched area, best if applied on mulch to help filter soaps/fats, discharge 3' above mulch, make sure rain will not backflood,


• typical US family produces 140 gallons of greywater a day, 51,000 gallons per year in irrigation ^5


• never been a case of greywater transmitted illness in the US ^8


• do not drink greywater


• do not concentrate greywater in an area that can become waterlogged


• do not use household drains to "throw something away", there is no "away"., use 3-way valve if you must "dispose" of something you don't want in your greywater basin


• need at least 2 cm drop per meter, 2% grade, 1/4" per foot, to gravity feed


• discharge at least 3 m from foundation


• create an oasis zone with higher water demanding plants with greywater


• do not discharge near a well under same rules as septic tank placement


• be careful which cleaning products you put down drains, even those labled biodegradable, natural or eco-friendly necissarily mean they are safe for greywater discharge, avoid chlorine, drain cleaners, bleach, fabric softener, detergents with whiteners, softeners, enzymes, anything sodium based, borax, boron, peroxygen, sodium perborate, sodium typochlorite, petroleum distillate, alkylbenzene, salt, disinfectants,


• for a list State of California Dept of Water Resources, www.owue.water.ca.gov - Greywater Guide: Using Greywater in your landscape


• bathroom sink, shower, are the cleanest greywater,


• a/c has a bit of salt


• kitchen sink is "dirty" from all the food scraps,


• www.greywater.com


• "Water From the Sky" by Michael Reynolds at www.earthship.net


• "The Composting Toilet System Book" by Carol Steinfeld / David Del Porto at a href="http://www.ecowaters.org">www.ecowaters.org


• Art Ludwig "The New Create an Oasis with Greywater"


• can use infiltration chambers or french drain like outlets for greywater


• shield any non-perforated pipe to prevent erosion, can use an upside-down 5-gallon bucket with holes large (1.5-2") drilled in the sides, cut access hole in the bottom(now the top) and bury it, cut another hole to let the greywater pipe in, [fig 12.11, pdf 333], backfill the bucked/shield with mulch for better infiltration,


• estimate your discharge rate to size basins, pipes, etc


• tap lines in an existing home as high as needed to give enough gravity flow


• in dryland areas with less than 20" of rain per year, periodically apply fresh water to leech out salts,


• can use siphon to get water out of bathtubs or other places that you can't plumb,


• multiple redirects from washing machine to different parts of the yard


• outdoor showers, built on platform, multiple redirects,


• Pima county AZ requires form "R18-9-E303. 4.03 General Permit for Composting Toilet" which also costs $500. In Pima county, even with permitting fees, a greywater system will cost about half of a septic or sewer hookup


• composting: under 42F/5.5C : little to no activity 42F/5.5C - 67F/19.4C : psychrophillic (actinomycetes and fungi), moldering process 68F/20C - 112F/44.4C : mesophilic bacteria, typical range for composting toilets 113F/45C - 160F/71.1C : thermophilic bacteria,typicaly too high for composting toilets unless managed (moisture/turning)


• The Humanure Handbook by Joseph Jenkins : pathogens die at 143F in one hour, 122F in one day, 115F in one week, 110F in one month,


• Epilogue


• We all live upstream and downstream of our neighbors


• water harvesting is site specific


• don't get discouraged if what you are doing seems small, every little bit helps and is an example to the future,


• just get started, you'll gain experience fixing your early mistakes, also why you should start small,


• Carlos Ochoa, 49, Santa Cruz, played in the river as a child, working with Richard Martinez, families have lived in the area since the 1800s, memories of verdant landscapes, large river-side trees, could walk barefoot all summer long, rope swings into the river, watercress on the water, currently soil-cement mix stabilizes the banks, runoff is directed away from vegetaion to dry river bed, irrigation is pied in for vegetation,


• "We killed that river with our overpumping. We used too much water and we keep increasing our use."


• "Why don't people vqalue their waater? Why do they waste so much? Why do they drain away water and then give city drinking water to plants?..."


• "Yeah, well, we gota do it.We have to show people how to do it. We gotta get more of them doing it. We get enough of them doing it, and we'll bring that river back." -Carlos,


• transportation departments can coordinate gabions along roads, libraries/churches for public lectures, public buildings can become demonstratoin sites,


• Appendix 1: Patterns of Water Flow and Erosion with their Potential Water-harvesting Response


• Sheet flow, Pedastals, Channel flow, Head-cut, Rills, Gullies, Bank cutting,


• Sediment size shows flow of water, slower for smaller rocks to faster for boulders,


• Vegetation, floods will scour out small vegetation,


• break and key lines


• high water marks,


• scour holes,


• Indicator species, populus fremontii (Cottonwood) and Sycamore (Platanus wrightii) indicate shallow groundwater/perennial flos Ambrosia deltoidea (Bursage) is found around annual flows Peppergrass (Lepidium thurberi) and tumbleweed (Salsola iberica) short term moisture indicator


• Dragonflies found near open bodies of water, Toads can indicate ephemeral water source, or too small for predator fish pool


• Appendix 2: bunyip water levels and A-frame levels


• Appendix 3: Water-harvesting earthworks calculations


• Appendix 4: Plant Lists and requirements for Tuscon, AZ


• www.water.az.gov/adwr/Content/Conservation/LowWaterPlantLists/default.html


• How many inches plants need lists,


• how many inches are needed below the plant's canopy, can convert this to gallons,


• reduced water can lead to shorter/smaller plants


• "Harvesting Rainwater for landscape Use" be Patricia H. Waterfall and Christina Bickelmann, 2004, free publication


• Appendix 5: Sizing Kitchen Resource Drain (KRD) in Arizona


• test soil percolation, dig hole 15" around, 12" deep, vertical sides and flat bottom, pour water into the hole for several hours to completely saturate the soil around it (simulating worst-case scenario rains), once saturated, fill the hole 6" and time how many minutes it takes each inch to percolate into the soil, repeat this process the next morning, use the longer time in calculations,


• Appendix 6: Resources


• www.harvestingrainwater.com


• References:


• "The Negev: The Challenge of the Desert" by Evenari, Shanan, Tadmor


• "Food from Dryland Gardens" by Cleveland, Soleri


• "Final Report: Demonstration of the Sustainability of Harvested Rainwater in Arid Lands to Meet Water Requirements and to Improve Quality of Runoff R9 # 03-478" 2005, Tuscon, Phillips, Landcaster,


• "Alternative Irrigation: The Promise of runoff Agriculture" by Barrow


• "Semiarid Soil and Water Conservation" by Finkel


• "Combining Storm and Rainwater Harvesting at Commercial Sites" by Bill Hoffman presentation


• "Paving our way to water shortages: How sprawl aggravates the effects of drought" www.smartgrowthamerica.org/Sprawl%20Report-FINAL.pdf


• Stormwater as a resourceL How to harvest and protect a dryland treasure" www.nmenv.state.nm.us/swqb/Storm_Water_as_a_Resource.pdf


• "Daylighting: New Life for Buried Streams" by Richard Pinkham www.rmi.org/images/other/Water/W00-32_Daylighting.pdf


• "Gully Development and Control: The Status of Our Knowledge" by Burchard H. Heede of Rocky Mountain Forest and Range Experiment Station (Fort Collins)


• www.earthworksinstitute.org/publications/publications.html


• "Recommendations for the Control and Reclaimation of Gullies" by Quincy Ayres of Bulletin 121: Iowa Engineering Experiment Station 1935


• "Native American Methods for Conservation and Restoration of Semiarid Ephemeral Streams" by JB Norton of Journal of Soil and Water Conservation Oct 2002 p.250


• "Dark Days on Black Mesa" by John Dougherty www.phoenixnewtimes.com/issues/1997-04-24/feature2.html


• "Agroecological Restoration in Southwestern Woodlands: A comparative analysis of water harvesting and Erosion control methods" by Craig Sponholtz 607 Salazar St. Santa Fe NM 87505


• "Food Plants of the Sonoran Desert" by Wendy C. Hodgson


• "Complete Guide to Selecting and Growing More than 100 Varieties for CA, AZ, TX, Gulf Coast, FL" by Lance Walheim


• "Shrubs and Trees of the Southwestern Deserts" by Janice Bowers


• "Hackberry/Walnut Guild" by Tim Murphy


• www.greywater.com