water and land use › pmn › files › 412689.pdf0.4 101 6% 0.5 53 3% 0.6 25 1% 0.7 15 1% 0.9 30...

Water and Land UseExecutive Water Finance Board

The importance of objective data

• “Most of the world will make decisions by either guessing or using their gut. They will be either lucky or wrong.”- SuhailDoshi, CEO, Mixpanel

• “It is a capital mistake to theorize before one has data.”- Arthur Conan Doyle, Author of Sherlock Holmes

https://www.google.com/url?q=http://www.newyorker.com/magazine/2015/05/18/tomorrows-advance-man&sa=D&ust=1463700706971000&usg=AFQjCNHvH6dZFX9x2p8d2eqjsle-FaOXNQ

https://www.google.com/url?q=https://mixpanel.com/&sa=D&ust=1463700706971000&usg=AFQjCNGf99KrFk9fW4B2tK1w-Xywy0OARg

https://www.google.com/url?q=http://www.arthurconandoyle.com/&sa=D&ust=1463700706972000&usg=AFQjCNGKCHBrVFfsLkgLmk2-tVPa3P2N_g

Different Perspectives

Image source: https://balajiviswanathan.quora.com/Lessons-from-the-Blind-men-and-the-elephant

Source: Ariely, Dan. Lecture at Duke University, Spring 2013



Source: Adelson, Edward H., Vision Science, MIT 1995

How much water did it take to make this cup of Coffee?

8 oz?

200 Liters?

Source: Tompkin, Jonathan. Lecture at University of

Illinois at Urbana Champagne, Fall 2012

Embedded Water

• In a cup of coffee• 250 ml (8 oz.) of water in the cup

• Including irrigation - 200 liters! (Over 50 gallons)

• Consumers are using over 200 liters of water for a cup of coffee

• Embedded water in common products• 1 Kg of wheat = 1300 liters

• 1 kg Rice = 3500 liters

• 1 kg of hamburger = 15,000 liters

• 1 kg of Microchips = 15,000 liters

• 1 kg of cotton shirts = 4,000 liters

• Car manufacturing = 500,000 liters of water

Source: Tompkin, Jonathan. Lecture at University of Illinois at Urbana Champagne, Fall 2012

How much water did it take to make this cup of Tea?

20 Liters

Source: Tompkin, Jonathan. Lecture at University of Illinois at

Urbana Champagne, Fall 2012

Land Use and Water

• Land use impacts water use…period.

• Land use does not equal water use

• “How we grow matters”

County development – Lot Sizes

• Used County Assessor data to determine average lot size by year in several counties

• Selected only “residential” lots with a “year built”

Salt Lake County

Source: Utah's State Geographic Information Database – Salt Lake County Parcels LIR layer: Spring 2018

Salt Lake County

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 More

1996 Percent

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 More

2016 Percent

Bins Frequency

2016

Percent

0.1 333 25%

0.2 521 39%

0.3 272 20%

0.4 85 6%

0.5 44 3%

0.6 25 2%

0.7 11 1%

0.8 7 1%

0.9 6 0%

1 15 1%

More 25 2%

Bins Frequency

1996

Percent

0.1 772 12%

0.2 1763 26%

0.3 2438 37%

0.4 855 13%

0.5 309 5%

0.6 131 2%

0.7 41 1%

0.8 21 0%

0.9 20 0%

1 90 1%

More 216 3%

Lot size in acres Lot size in acres

.22 average lot.33 average lot

Source: Utah's State Geographic Information Database – Salt Lake County Parcels LIR layer: Spring 2018

Utah County

Source: Utah's State Geographic Information Database - Utah County Parcels LIR layer: Spring 2018

Utah County

0%

5%

10%

15%

20%

25%

30%

35%

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 More

1996 Percent

0%

5%

10%

15%

20%

25%

30%

35%

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 More

2016 Percent

Bins Frequency

1996

Percent

0.1 716 21%

0.2 707 21%

0.3 1018 30%

0.4 327 10%

0.5 219 6%

0.6 90 3%

0.7 40 1%

0.8 20 1%

0.9 23 1%

1 52 2%

More 169 5%

Bins Frequency

2016

Percent

0.1 1266 31%

0.2 898 22%

0.3 989 24%

0.4 341 8%

0.5 159 4%

0.6 155 4%

0.7 45 1%

0.8 31 1%

0.9 16 0%

1 38 1%

More 119 3%




Davis County

Source: Utah's State Geographic Information Database Davis County Parcels LIR layer: Spring 2018

Davis County

Bins Frequency

1996

Percent

0.1 207 10%

0.2 495 25%

0.3 832 42%

0.4 188 9%

0.5 93 5%

0.6 49 2%

0.7 23 1%

0.8 9 0%

0.9 12 1%

1 25 1%

More 61 3%

Bins Frequency

2016

Percent

0.1 240 18%

0.2 294 22%

0.3 440 32%

0.4 189 14%

0.5 102 8%

0.6 36 3%

0.7 11 1%

0.8 11 1%

0.9 5 0%

1 0 0%

More 28 2%


Source: Utah's State Geographic Information Database - Davis County Parcels LIR layer: Spring 2018

Washington County

Source: Utah's State Geographic Information Database - Washington County Parcels LIR layer: Spring 2018

Washington County


.38 average lot .36 average lot


Bins Frequency

1996

Percent

0.1 581 35%

0.2 343 20%

0.3 366 22%

0.4 101 6%

0.5 53 3%

0.6 25 1%

0.7 15 1%

0.9 30 2%

1 24 1%

More 146 9%

Bins Frequency

2016

Percent

0.1 283 16%

0.2 396 23%

0.3 691 39%

0.4 146 8%

0.5 67 4%

0.6 44 3%

0.7 16 1%

0.9 22 1%

1 19 1%

More 75 4%

Is this our smaller lot future?

https://www.newfrontiertinyhomes.com/tiny-house/cornelia/ http://planning.unc.edu

Smaller lots…larger homes…less lawn


Are smaller lots more efficient?

• It depends…

• Multi-family and rental units less sensitive to:• price changes

• weather

• long-term trends/billing history

• Single family units may use less per capita

• Water is decoupling from density

• Landscaping is more important than lot size

Color Infrared Imagery

https://www.geomart.com/products/aerial/cir.htm

http://cstars.metro.ucdavis.edu/files/3613/4

419/0702/Lecture_3-Leaves__Plants.pdf

http://www.mngeo.state.mn.us/chouse/airphoto/cir.html

Remote Sensing

Salt Lake County Example

~.25 acre lots


~55% Vegetation Cover

Desert oasis?

Photo Credit: VisitStGeorge.com

Recent Washington County Large Lots

~.5 acre lots


~28% Vegetation Cover


>.5 acre lots


~1.5% Vegetation Cover

A small lot example…

These lots average just .1 acre

A small lot example…

Vegetation coverage ~ 30%

A small lot example

Ivins

~22%

~16%

<2%

Macro Analysis

• Analyzed subset of Washington County.

Macro Analysis


• Only developed areas

Macro Analysis


• Only developed areas

• >5,000 acres of vegetation

• ~17% of developed area

Percent Vegetative Cover

St. George – Vegetation vs Water Use


• ~44% vegetation cover

• 3% golf courseVegetation

Washington County Water-Related Land Use

Irrigated

Not Irrigated

Riparian

Sub-Irrigated

Urban

Water

Source: Utah's State Geographic Information Database – Water Related Land Use layer: Spring 2018

- ~12,000 acres

The Future

• Washington County is growing

• What will growth look like?• More than double the population by 2065

Washington County Growth

1991~48,000 people~15,000 acres~3.3 PPDA


2017~165,000 people

~60,000 acres~2.7 PPDA


2065?~508,000 people~122,000 acres

~4.2 PPDA

*Note: potential growth scenario for illustration only – not based on actual development plans

Washington County 2045 - 2065

• More than twice the population

• Twice the land developed?

• How much new irrigated vegetation? • ~ 10,000 new acres of vegetation at current rates.

• ~ 30,000 acre feet of water per year for new irrigation needs*

• *At least some ag water likely to convert to M&I

33%

25% less use per person; new supply from projects, little

from farms; max 30% grass in yards/parks

24%

15% less use per person; new supply from projects and

farms; max 50% grass in

yards/parks

20%

40% less use per person; new supply from local projects and farms; almost

no grass in yards/parks

13%

Same use per person as

today; new supply from projects and

farms

12%



yards/parks

S U R V E Y R E S U L T S :

SC EN AR IO C H OIC ES( W AT E R - S TAT E )

35%

25% less use per person; new supply from projects, little

from farms; max 30% grass in yards/parks

26%



yards/parks

29%

40% less use per person; new supply from local projects and farms; almost

no grass in yards/parks

5%

Same use per person as

today; new supply from projects and

farms

5%



yards/parks

S U R V E Y R E S U L T S :

SC EN AR IO C H OIC ES( W AT E R – W A S H I N G T O N C O U N T Y )

+2% +9% +2% -8% -7%

Difference from state

Localscapes…

https://localscapes.com/

Water Strategy Land Use Recommendations

• Water-efficient by design

• Integrate water planning and land use planning to achieve long-term water use efficiencies in urban areas.

• Include water conservation and water source protection elements in city and county general plans

• Enact zoning ordinances that allow the housing market to move to higher densities

• Enact landscaping and other ordinances

• Utilize dual water source delivery systems where feasible

Source: Utah's Recommended State Water Strategy

Key Points

• We need good data

• Lot sizes decreasing, home sizes increasing

• Washington County (and all of Utah) has room to GROW

• HOW we grow matters

• Social “norms” can be powerful conservation tools

The End…

water and land use › pmn › files › 412689.pdf0.4 101 6% 0.5 53 3% 0.6 25 1% 0.7 15 1% 0.9 30...

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