supplement to report: commute sheds as a regional water management decision tool this is a working...

Supplement to Report:Commute Sheds as a Regional Water Management Decision Tool

This is a working file, subject to updates.

For individual use only.Please contact author prior to redistribution or citation.

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Commute Shedsas an Integrated Watershed Management Decision Tool

Benjamin Young LandisNicholas School of the EnvironmentDuke University

BACKGROUND: OnTheMap is a new software that analyzes commute sheds – a type of regional resource analysis

QUESTION: Does commute shed analysis have applications in regional water supply decision making?

CASE STUDY: Upper Neuse River Basin, NC

Abstract

RaleighWake Forest, Rolesville, Knightdale, Wendell, Zebulon, Garner

RaleighWake Forest, Rolesville, Knightdale, Wendell, Zebulon, Garner

HillsboroughHillsborough

South GranvilleButner, Stem, Creedmoor

South GranvilleButner, Stem, Creedmoor

DurhamDurham

Upper NeuseRiver BasinUpper NeuseRiver Basin

Falls Lake

Chapel Hill(Cape Fear Basin)Chapel Hill, Carrboro

Chapel Hill(Cape Fear Basin)Chapel Hill, Carrboro

Jordan Lake(Cape Fear Basin)Cary, Morrisville, Apex

Jordan Lake(Cape Fear Basin)Cary, Morrisville, Apex

Jordan Lake

Kerr Lake (Roanoke Basin)Oxford, Henderson, South Henderson

Kerr Lake (Roanoke Basin)Oxford, Henderson, South Henderson

“Water supply is no longer just a function of individual communities. Clearly, it's a regional issue.”

-- Sydney Paul MillerWater Resources Program Manager

Triangle J Council of Governments(“Will the Water Run Out?” Town Hall, 08 January 2008)

• Disparate Supply: Some cities have adequate water supplies and facilities. Some do not.

• Cities are moving towards regional sharing and optimization of water supplies

• Need new tools to inform water sharing decisions and trace flows of water benefits

• Can commute sheds offer a new perspective?

Water Supply Around the Upper Neuse

• Watershed:– The flow of water from sources to receiving sink

• Commute shed:– The flow of commuters from home city to city of

employment

• Analyzed by tourism and labor economists• Used by city planners to attract development

and site public services

Commute Sheds and OnTheMap

• OnTheMap version 3– U.S. Census Bureau, 2008

• Determines:– Number of workers in a home city– Number of workers that commute– To which other cities these workers commute

• Analyze by subgroups (e.g. by earnings)


• Recall: Cities are moving towards regional sharing and optimization of water supplies

• Cities would physically connect and benefit from each other’s water supply

• But, are cities already “virtually connected” and benefiting from each other’s water supply?

Applying Commute Sheds toRegional Water Supplies

• A city invests in water supply and infrastructure to help sustain its residents

• Residents work, and generate economic impact

• Thus: – Water supply helps generate economic impact– Economic impact is a benefit of water supply


• When residents commute to a different city to work, they export their economic impact

• These commuters also export the benefits of their home city’s water supply

• Commute sheds represent the exports of water supply benefits amongst cities


• Application: Analyze the exports of water supply benefits amongst cities, illustrating their “virtual connection”

• Analysis Steps: 1. Find number of resident workers using OnTheMap 2. Estimate economic impact generated by workers 3. Determine portion exported by commuting workers

• Unit of Comparison: city boundaries– As a proxy for water utility service areas

Exports of Water Supply Benefits

• GDP is standard unit of economic impact• City-level GDP not available

• Used primary job earnings per worker reported by OnTheMap to estimate economic impact

Monthly Earnings Workers Estimate Product Months Per Year

<$1,200 36,639 x $1,200 = 43,966,800 x 12 = 527,601,600

$1,201 to $3,400 70,128 x $3,400 = 238,435,200 x 12 = 2,861,222,400

> $3,400 72,216 x $6,800 = 491,068,800 x 12 = 5,892,825,600

ANNUAL ECONOMIC IMPACT Supported by RALEIGH = $9,281,649,600


UPPER NEUSE BASINWater Supply Benefits

Supported by Each CityIn Terms of Annual Economic

Impact of Residents, 2006


Supported by Each CityIn Terms of Annual Economic


DURHAM$4,590 million

HILLSBOROUGH$149 million

SOUTH GRANVILLE$126 million

SOUTH GRANVILLE$126 million

RALEIGH$9,282 million

$9,281 million$8,482million

Durham-$800 million

Hillsborough-$6.2 million

South Granville-$4.9 million

$8,470million$8,358million

Chapel Hill-$113 million

$7,554million

Jordan Lake-$803 million

Kerr Lake-$31.8 million

$7,522million

RALEIGH $4,713 million

(50.5% retained)

RALEIGH $4,713 million

(50.5% retained)

All Other Basins-$2,809 million

$8,475million

RALEIGHWater Supply Benefits

ExportedIn Terms of Annual Economic


RALEIGHWater Supply Benefits



Raleigh-$503 million

Hillsborough-$22 million


(50.2% retained)


(50.2% retained)

Chapel Hill-$500 million

Jordan Lake-$205 million

Kerr Lake-$16 million

All Other Basins-$1,033 million





South Granville-$7.2 million

DURHAMWater Supply Benefits



DURHAMWater Supply Benefits



RALEIGH-$296 million to Durham

DURHAMNet Imports of $349 million

HILLSBOROUGH-$23.2 million to Durham -$2.0 million to Raleigh

SOUTH GRANVILLE-$28.6 million to Durham -$0.2 million to Hillsborough-$17.3 million to Raleigh

SOUTH GRANVILLE-$28.6 million to Durham -$0.2 million to Hillsborough-$17.3 million to Raleigh


Net ExportsIn Terms of Annual Economic





CHAPEL HILLNet Exports: -$191 million~83% from Durham

JORDAN LAKENet Imports: $841 million~50% to Durham~50% to Raleigh

KERR LAKENet Imports: $26 million~75% to Raleigh







RESULTS• Amongst Upper Neuse water systems, Durham

is a net importer of water supply benefits– Durham is a net importer of workers– These workers are supported by other cities’ water

supplies

• Amongst regional basins, the Upper Neuse is a net importer of water supply benefits, especially from Jordan Lake


APPLICATIONS FOR DECISION-MAKING• Reveals the interdependence of cities within

and near the Upper Neuse River Basin

• Helps visualize “virtual” exports of water resources

• Can inform negotiations and decisions– Intra- and inter-basin water transfer agreements– Joint financing of new water infrastructure


Conclusions

• Novel application of commute shed analysis

• OnTheMap can help analyze the exports of water supply benefits amongst cities, illustrating this “virtual connection”

• A versatile, easily-accessible tool to complement more costly research such as valuation and modeling analysis

COVER PHOTO CREDITS: traffic scene: A.F. Silva; Lake Michie aerial view: City of Durham

supplement to report: commute sheds as a regional water management decision tool this is a working...

Documents

raleigh water supply

benefit of water supply

flow of water

regional water supplies

adequate water supplies

onthemap slide

residents commute

trace flows of water