Flagstaff's Virtual Water Trade Network: Understanding How Cities Consume and Outsource Water to Inform Policy

Transcription

1 Flagstaff's Virtual Water Trade Network: Understanding How Cities Consume and Outsource Water to Inform Policy Richard Rushforth School of Sustainable Engineering and the Built Environment Arizona State University Presentation to the Coconino Plateau Water Advisory Council Technical Advisory Committee 25 September 2014

2 Overview 1. Background 2. Data Sources/Methods 3. Flagstaff s Internal Water Footprint 4. Benchmark Water Consumption 5. Flagstaff External Water Footprint 6. Flagstaff s Virtual Water Trade Network 7. Revealing Virtual Water Vulnerability 8. Conclusion

3 1. Background Urban metabolism is an established framework for studying cities as a unit Resource requirements for socio-technical process that occur in cities Relationship between a city and surrounding hinterlands Urban metabolism studies focus on the direct resources requirements Water, electricity, fuel consumption, food Current study focuses on the inputs required to produce the resources inputs demanded by a city Focus of the study: Resources Indirectly consumed by a city

4 1. Background Economic activities in a city can be classified as primary, secondary, tertiary, and quaternary activities (Kenessey, 1987) Primary Activities Agriculture, Forestry, Fishing, Mining Secondary Activities Construction, Manufacturing Tertiary Activities Transportation, Utility Services, Wholesale and Retail Trade Quaternary Activities Finance, Insurance, Real Estate As cities grow and compete, specialization occurs in the tertiary and quaternary sectors of the economy and primary and secondary sectors become outsourced Flagstaff hosts secondary, tertiary, and quaternary sectors Kenessey, Z. (1987), The Primary, Secondary, Tertiary And Quaternary Sectors Of The Economy. Review of Income and Wealth, 33: doi: /j tb00680.x.

5 2. Data Sources/Methods City of Flagstaff Utilities Division Water Resources Management Data year 2007, 2011 Commodity input and output data Freight Analysis Framework from the DOT Federal Highway Administration Freight Management and Operations Data year 2007 US water withdrawal data USGS Kenny, R. F., Barber, N. L., Hutson, S. S., Linsey, K. S., Lovelace, J. K., and Maupin, M. A. (2009). Estimated use of water in the United States in U.S. Geological Survey Circular 1344, Reston, VA, 52. Data year 2005 US Census American Factfinder Data year 2007 US Economic Census Data year 2007 Water Stress Index Tidwell, V., Kobos, P., Malczynski, L., Klise, G., and Castillo, C. Exploring the Water-Thermoelectric Power Nexus. Journal of Water Resources Planning and Management :5, Data Year 2005

6 2. Data Sources/Methods Internal Water Footprint 1. Tabulated using City of Flagstaff Data External Water Footprint 1. Determine the total output of commodities for each FAF zone 2. Disaggregate FAF zone statistics to the county 1. Production by labor share 2. Consumption by population 3. Harmonize with County Water Use 4. Calculate a Water Intensity for each county 5. Multiply By Flagstaff demand

7 3. Flagstaff s Internal Water Footprint Flagstaff s water consumption is distributed to the higher ends of the economy. The tertiary and quaternary sectors of the economy. Manufacturing, IT, education, public administration Relatively low volumes of water used in primary and secondary economic sectors Agriculture, forestry, mineral extraction, etc. Data shown are potable water consumption and do not include reclaimed water deliveries. Water Consumption in Flagstaff By Economic Sector (acre-feet) Economy Sector Manufacturing (Direct) Residential (Indirect) Food and Lodging (Direct) NAU (Direct) Total % Allocation Primary % Secondary % Tertiary 7 1,278 2,055-3,340 41% Quaternary - 3, ,330 53% Total 355 4,677 2, ,231

8 4. Benchmarking Land Uses Parcel area was used to benchmark metered water consumption for non-residential land uses. The data presented is just for potable water consumption and does not include reclaimed water deliveries. Land uses types considered: Industrial, commercial, residential, open space, parks, and institutions, etc. Total water consumption was a poor indicator of water use intensity (r 2 < 0.50). In general, industrial land uses had higher water use intensities higher consumption, but some types of residential land uses were found to have the highest water use intensities.

9 4. Benchmarking Land Uses Commercial: Neighborhood Commercial: Office / Business Park - Light Industrial Commercial: Regional/Community Industrial: Heavy Industrial: Light/Medium Insitutional: Elementary School Insitutional: Hospital/Medical Center Insitutional: University Institutional Land Bank: PRA 3 Open Space: Golf Course Open Space: Parks Open Space: Urban Open Space Residential: High Density (>12 du/ac) Residential: Low Density (1-5 du/ac) Residential: Medium Density (6-12 du/ac) Residential: Mixed Neighborhood Residential: Very Low Density (<1 du/ac) WATER CONSUMPTION INTENSITY (GALLONS PER SQUARE FOOT) WATER CONSUMPTION (ACRE FEET) Metered Consumption (ac-ft) Gallons per Square Foot

10 5. Flagstaff s External Water Footprint The external water footprint of a city is many times greater than the internal water footprint. Resource requirements and geography constrain primary activities in urban areas. Primary sector activities are typically low value, high water use activities are outsourced by cities to rural areas. Sector Outsourced Water Agriculture 294,731 acre feet Industrial 638 acre feet Mining 1,501 acre feet Total 296,870 acre feet

11 6. Flagstaff s Virtual Water Trade Network Agricultural Goods Industrial Goods Mining Goods Total External Footprint

12 6. Flagstaff s Virtual Water Trade Network The vast majority of water use is outsourced to nearby rural areas due to transportation costs and mostly high water value intensity goods travel long distances.

13 7. Revealing the Virtual Water Vulnerability Tidwell et al. (2012) calculated a water stress index for each county in the United States: How does the geographically-weighted WSI of Flagstaff s virtual water trade network compare to its local WSI? Does a geographically-weighted WSI reveal information about the vulnerability of Flagstaff s virtual water? If so, are there proactive steps Flagstaff can take to shape the management of non-local resources through regional collaboration?

14 7. Revealing Virtual Water Vulnerability The Water Stress Index yields information on the over-allocation of available water resources, both surface water and groundwater. Scale of 0 to 1, where is highly stressed and 0 is not stressed. Study used the surface water WSI for each US county. For the study year, 2005 USGS water consumption data, Coconino County had a 0.29 WSI. Flagstaff s virtual water trade network had a weight 0.86 WSI. The high external WSI indicates the potential vulnerabilities in Flagstaff s virtual water trade network.

15 7. Revealing Virtual Water Vulnerability Areas in Arizona, California and Colorado present potential vulnerabilities in Flagstaff s virtual water trade network. Drought in southern Arizona and the Central Valley holds the potential to economically impact Flagstaff. Maricopa County presents the highest potential vulnerability in the network followed by Pinal County, Pima County and Cochise County. Interdependencies in the virtual water trade network present opportunities for regional collaboration, which holds the potential to create a more resilient socio-hydrological system.

16 8. Conclusions Flagstaff s external footprint is several times larger than its internal footprint. The production of primary sector goods takes place outside of the city due to limiting factors. Within the city, water consumption is skewed to higher levels of the economy due to economic specialization. Consumption is not an indicator how water allocations create value and must be tied to economic productivity and other indicators to develop effective water use thresholds. At the city level, economic trade can either reduce local water stress or expose city economic activities to non-local water stress. Understanding how and where water is outsourced can lead to better planning, regional collaboration, and increased resilience in the Flagstaff s socio-hydrological system.