Water Use & Demand Management - …web.sahra.arizona.edu/education2/hwr213/docs/Unit3Wk4/Hwr203demand...SW + GW + Eff + Imports = Ag + Muni + Ind + other. How do we quantify these

Water Use &Demand Management

Arizona Water Issues 1© 2012 – The University of Arizona – HWR203

Arizona Water Issues © 2012 – The University of Arizona – HWR203

Review: Natural Water Budget

Precipitation = Evapotranspiration +Runoff +Recharge +Change in Storage

Ppt = ET + RO + Rchg + S

2


Review: Anthro. Water Balance

Water “supplies” or sources

Water “demands” or uses

– Rivers & Dams

• “Surface Water”– Aquifers

• “Ground Water”– Treated Effluent

• “Reclaimed”– Imported water

• CAP

– Irrigation Water

• “Agricultural”– Homes & Cities

• “Municipal” or “Public Supply”

– Industrial

• also “Commercial”• Other

3

SW + GW + Eff + Imports = Ag + Muni + Ind + other

How do we quantify these terms?

Consider Municipal use:

– Muni + dM = f(…)?

– Inside = f(…)?

Arizona Water Issues © 2012 – The University of Arizona – HWR203 4

How do we quantify these terms?

Consider Municipal use:

– Muni + dM = f(Use, Pop, Growth, GPCD, inside, outside, …)

– Inside = f(family size, appliances, age, habits, …)



Why Demand Management?

What if you can’t find more water? Lower demand so as not to exceed supply Cheaper than increasing supply May allow more growth But:

– It may be difficult to quantify water savings through demand management

– Conserving too much may reduce flexibility in times of drought

6


Strategies

Minimize Unaccounted-for Water Shift Uses

– Ag to Urban– Highly Consumptive to low water use

Conservation– Ag– Industrial– Indoor– Outdoor

Reduce demand

7


Minimize Unaccounted-for Water

Replace or repair leaky water mains– Minimize system losses

Replace worn water meters

But …– Both fairly expensive

8


Shift Uses – Ag to Urban

Ag use:4-5 af/ac

Urban use:City blk ~ 4.5 ac,16 homes, 1 af/hh (high)=> 3.5 af/ac

9


Rank common indoor water uses from highest to lowest total volume?

Pick from:– Faucets– Shower/tub– Toliet– Washing machine

In42%Out

58%

Rank common indoor water uses from highest to lowest total volume?

Rank:– Toilet – Washing machine– Shower/tub– Faucets

Household Water Use

Which is larger –Indoor or Outdoor use?

121 gpcd

10


Age of construction matters

shower22%

faucet19%

toilet34%

washer25%

“Old” @ 60 gpcd

shower25%

washer25%

toilet25%

faucet25%

“New” @ 40 gpcd

11


Household Water Use

12


Typical SW Values

City GPCDAlbuquerque, NM 95

El Paso, TX 114Tucson 120Mesa 123

Glendale 131 $35/moTempe 140Phoenix 165

Scottsdale 169Fresno, CA 261 $108/mo

13


What does it mean to “Beat the Peak”?

14

Pete the Beak

New 2013 - TW Water Smart

Conservation Incentive Programs– Toilet rebates

12,000 new x 3 gal x 365 days x 11 f/d = 144 Mgal/yr saved (443 af/y)

– Washer rebates– Rainwater harvesting

~$2,000– Gray water


Partnerships

cms3.tucsonaz.gov/water/watersmart

Water Smart – Water AuditsDo your part, be water smart everyday

Water Smart– Rainwater harvesting

incentives– cms3.tucsonaz.gov/wa

ter/rwh-l2steps– Residential Drip Irrig.– Gray water rebate– Hands-on Waterwise

garden design

Water Audits– content …


credit: Tucson Water

SmartScape• Soils, Plants & Water

• Desert - Adapted Plants

• Automated Irrigation Systems

• Landscape Water Management

• Landscape Design & Renovation

• Plant Selection & Installation

• Plant Disorders & Weeds

• Maintaining Desert - Adapted Plants

• Integrated Pest Management


credit: Tucson Water

Residential Conservation: Cost/Benefit

SWH 8(6), 2009


Pricing

Increase water charges to increase conservation

Block rate structure: higher water users may more for their water (see next slide)

May reflect the ‘scarcity’ value of water Is it ethical? What about the right to

water?

19


Seasonal considerations

$20

$40

$50

20


Conservation Education Bill inserts Flyers Billboards Public service announcements Workshops and Events Can make water users aware of the need to

conserve water

– Cheap! But …

– Very difficult to prove its effectiveness

21


Indoor and Outdoor Use Efficient appliances

– dishwashers, frontloading washing machines Fixture retrofits

– low-flow toilets, showerheads, and faucets Landscape conservation measures

– xeriscaping, turf removal, water harvesting, drip irrigation

Rebates may be offered for any of the above Las Vegas pays people $1/sq ft. to remove turf. Offsetting behavior? Efficiency?

22


Indoor use Outdoor use

Pools (~500 ft2)

• loose 50 gal/ft2/yr

Evaporative coolers (2000 hrs)

• w/ bleed ~10 gal/hr

• w/o bleed ~ 3 gal/hr

Garden hose (~15 min)

• 10 gal/min

Drip Irrigation (30 min, 150 d)

• 10 gal/hr

Car Wash (~5 min, weekly)

• 5 gal/min

Mist system (5 hrs/d, 100 d)

• 4 gal/hr23

Arizona Water Issues© 2012 – The University of Arizona –

HWR203

Evaporative Coolers

Cheaper than airbut … System w/ bleed

– 10 gal/hr System w/o bleed

– 3 gal/hr

Typical usage– 2000 hrs (83 days)

So– 20,000 gal/yr

24


Appliance and Fixture Use

25


Water meter traces reveal details of domestic demand

26

Arizona Water Issues© 2012 – The University of Arizona –

HWR203

Problems found with aging ULF toilets

0

5

10

15

20

25

30

35

40

45

Double Flush FlapperLeak

High FlushVolume

SomeProblem

13.515.3

26.4

42.9

Percent of Households Experiencing Problem

Bathroom27


Reclaimed Water

Link between supply and demand management

What is it?Why use it?Who uses it? How is it treated?

www.wwm.pima.gov28


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.

29

CISTERN INSTALLED FOR GRAYWATER REUSE SYSTEM

Gray WaterGRAY WATER IS WATER FROM THE BATH, SHOWER, WASHING MACHINE OR BATHROOM THAT CAN BE USED FOR IRRIGATION NEEDS

* 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/


7 Principles of Xeriscaping

Good planning & design

Low water use plants Appropriate turf areas Efficient irrigation Soil improvements Use of mulches Appropriate

maintenance


www.amwua.org/landscape/landscape_principles.html

Cred

it: C

harle

s M

ann

Phot

ogra

phy

Cred

it: K

ent

New

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Documents

Water Use & Demand Management - …web.sahra.arizona.edu/education2/hwr213/docs/Unit3Wk4/Hwr203demand...SW + GW + Eff + Imports = Ag + Muni + Ind + other. How do we quantify these