Consumptive Use by Crop Outdoor Conservation & Rainwater Harvesting http://ag.arizona.edu/crop/irrigation/cusecharts.html 1 2010 The University of Arizona HWR203 2 What does plant water use look like? Tiffway bermudagrass in summer and overseeded ryegrass in winter. cals.arizona.edu/azmet/phxturf.html 3 Weekly Consumptive Use (in) Turf Grass Consumption - Weekly Tiffway bermudagrass in summer and overseeded ryegrass in winter. 2 cals.arizona.edu/azmet/phxturf.html Phoenix- 57.5" 1.8 Tucson - 58.9" 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 1 3 5 7 9 111315171921232527293133353739414345474951 Week 4 Pool ~300 ft 2 Outdoor water use rates Evaporation ~ 78 /yr = 14,600 g/y Drain & Fill ~ 10,000 g Total ~25,000 g/y Grass Bermuda + Winter Rye ~50 = 9,400 g/300 ft 2 Drip 30*.25g*365d = 2700 g Car Washing 12/y*2 g/m* 10m = 240 g 5 http://ag.arizona.edu/azmet/phx/lawnfaqs.htm (vs. 1000 + gal/mo interior) 6
7 Principles of Xeriscaping More on Xeriscaping Good planning & design Low water use plants Appropriate turf areas Efficient irrigation Soil improvements Use of mulches Appropriate maintenance Credit: Kent Newland Credit: Charles Mann Photography www.amwua.org/landscape/landscape_principles.html 7 8 Advantages: Disadvantages: Water Harvesting WHY HARVEST RAINWATER? Water Source Precipitation is the primary source of fresh water within the hydrologic cycle and is naturally distilled. Can help utilities reduce the summer demand peak. Can provide a water source when groundwater is unacceptable or unavailable or can augment limited groundwater supplies. Rainwater is free. Supplementing rainwater can potentially reduces consumers utility bills. Water Sink Utilizing water on-site minimizes water leaving a site. Reduces flow to stormwater drains and also reduces nonpoint source pollution. Can help delay expansion of existing water treatment plants. 9 10 PASSIVE VS. ACTIVE RAINWATER HARVESTING THE BIG PICTURE PASSIVE A system of water harvesting requiring little energy input and little effort on the part of the owner after the system is constructed. Example Methods Earthen Berms and Swales Ground Infiltration ACTIVE A system of water harvesting requiring energy input and maintenance on the part of the owner after the system is constructed. Examples include: Cisterns Constructed Ponds and Wetlands 11 Source: B. Lancaster 12
Source: N. Connolly Berms and Swales Phillips, 2003, ASLA Conf 13 14 Rainwater Harvesting @ Home Water Conservation at Home http://www.ci.tucson.az.us/water/conservation/ 15 16 Water Harvesting RW Harvesting around the World Rain water can be stored and used for gardening, etc BARGAIN STORAGE: With a lid or cover to reduce evaporation, rainwater can be stored for about.07 cents per gallon http://www.ag.arizona.edu/azwater/publications/sustainability/ www.eng.warwick.ac.uk/dtu/rwh 17 Chennai India Case Study & YouTube Video 18
RW Harvesting on Campus UA Optical Sciences 19 20 Culvert Cistern & Landscape Arch. UA Visitor Center Scott Calhoun, in Waterfall, UA CoopExt 21 22 36 ft Rainfall 1 inch = 1/12 ft 100 ft Area? 100 ft x 36 ft = 3600 ft 2 x 1/12 ft = 300 ft 3 x 7.5 gal/ft 3 = 2250 gal HW: Your Plan Site Plan Water flow arrows Water pools Landscaping features Label sources of runoff Calculate volume of runoff from 1 storm Optional: photo Due: Next Class Tucson Water Level 2 Project Plan 1/12 * 7.5 g/ft 2 ~ 0.6 cms3.tucsonaz.gov/water/rwh-plan 23 24
Passive Rain Gardens Rainwater Storage Cisterns Reclaimed Water Greywater Harvesting tfssolar.com/residential/rain-water/how-it-works-2/ Link between supply and demand management What is it? Why use it? Who uses it? How is it treated? 25 www.wwm.pima.gov 26 Gray Water Gray water involves rerouting the outflow pipes from tubs and showers, washing machines, dishwashers, evaporative coolers, and some sinks. Used water irrigates outdoor landscaping Regulations are strict and must be followed closely. Gray Water GRAY WATER IS WATER FROM THE BATH, SHOWER, WASHING MACHINE OR BATHROOM THAT CAN BE USED FOR IRRIGATION NEEDS CISTERN INSTALLED FOR GRAYWATER REUSE SYSTEM * The Water Conservation Alliance of Southern Arizona (Water CASA) is conducting a study to determine health risk associated with low-tech methods of graywater use http://www.ag.arizona.edu/azwater/publications/sustainability/ 27 28 29