Principles, Practices, and Tips for Water-Harvesting Earthworks and Rain Gardens

Transcription

1 Principles, Practices, and Tips for Water-Harvesting Earthworks and Rain Gardens by Brad Lancaster

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3 Abundance Scarcity sponge drain

4 Native Garden uses 83% less water; generates 56% less green waste and requires 68% less maintenance than the Traditional Garden.

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7 Abundance Scarcity sponge drain

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14 Earthworks to the periphery in small yards

15 Earthworks to the periphery in small yards

16 Before planting rain and life

17 After planting rain and life

18 Street runoff irrigating street trees

19 Street runoff irrigating street trees

20 See Harvesting Rain From a 1,000+-Year Storm Event blog entry at HarvestingRainwater.com

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23 Street runoff irrigating street trees

24 Always have an overflow and use it as a resource

25 Key elevation relationships of earthworks 1. Bottom of earthwork to top of overflow spillway 2. Top of overflow spillway to top of earthwork 3. Top of earthwork to precious things

26 Key elevation relationships of earthworks 1. Bottom of earthwork to top of overflow spillway 2. Top of overflow spillway to top of earthwork 3. Top of earthwork to precious things

27 Key elevation relationships of earthworks 1. Bottom of earthwork to top of overflow spillway 2. Top of overflow spillway to top of earthwork 3. Top of earthwork to precious things

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29 Key elevation relationships in a street-side basin

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31 Curb core hole 4-inch (100-mm) diameter

32 Speed / \ Depth Volume

33 Slope relationships in a street-side basin

34 Rain Garden Zones Bottom, Terrace, & Top

35 Rain Garden Zones Bottom, Terrace, & Top

36 Rain Garden Zones Bottom, Terrace, & Top

37 Rain Garden Zones Bottom, Terrace, & Top

38 Top ^ Terrace ^ Bottom >

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40 For Multi-Use Rain Garden Plants Lists see: Rainwater Harvesting for Drylands and Beyond, Volume 1 Plant Lists & Resources at

41 Maximize organic and living groundcover Yes No

42 Food-bearing native trees (Prosopis velutina) associated with mulched street runoffharvesting earthworks: Do NOT uptake heavy metals into edible plant tissue. Grow 33% larger than those without. More than double the trees potential sequestration of atmospheric carbon, passive cooling, and food production Enables the soil itself to sequester additional carbon Increases the natural pollutantfiltering/bioremediation ability of the soil to ten times greater than that of rock- or gravel-mulched soil Mitchell Pavao-Zuckerman, PhD Biosphere 2 & School of Natural Resources and Environment University of Arizona mzuckerman@arizona.edu

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44 Start at the top of the watershed and work your way down

45 Redbud Center, Austin, Texas

46 Start small and simple

47 Start small and simple

48 Infiltration basin / rain garden

49 Infiltration basin / rain garden

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52 Slow, spread, and infiltrate

53 Water-harvesting parking lot

54 Stepped basin

55 Slow, Boomerang spread, and berms sink / smile the water s berms flow

56 Contour swales Terraces

57 Contour swale or berm n basin

58 Dry-stacked urbanite retaining wall La Loma Development, Los Angeles, CA Porous urbanite patio Blue Agave Designs, Tucson, AZ

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60 Residential Rain Garden & Street Harvesting Benefit/Cost Ratio Initial Results Model representation On-the-ground potential practice Benefit/Cost Ratio: Direct benefits only: $4.4 / $1 $2.9 / $1 $3.1 / $1 $1.9 / $1

61 Green Streets Portland, Oregon

62 City of Portland, Oregon Sustainable Stormwater Overlays courtesy of Dave Elkin City is divided up into subwatersheds, and those of highest need are identified. Combined Sewer Overflowsand flooding are the typical problem

63 Conventional drainage design cost $144 million

64 Plan with sustainable stormwater strategies cost $86 million. $58 million savings due to the reduction of needed pipe replacement

65 SHOW THE FLOW

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67 Speed / \ Depth Volume

68 Scarcity Abundance drain sponge