Water Resources Water Resources Development Commission Development Commission

(HB 2661)(HB 2661)Water Supply & Demand Water Supply & Demand

Working Group – Working Group – Water Supply Sub Water Supply Sub

CommitteeCommittee

Major Existing Supply Data and Major Existing Supply Data and Studies Studies

Wednesday, January 5, 2011Wednesday, January 5, 2011

Existing Supply Data and StudiesExisting Supply Data and Studies

Demand and Supply Assessments for Demand and Supply Assessments for Phoenix, Tucson and Prescott AMA’s Phoenix, Tucson and Prescott AMA’s (ADWR, 2010)(ADWR, 2010)

Water Use Data for Pinal AMA and Water Use Data for Pinal AMA and Santa Cruz AMA’s (ADWR, 2009)Santa Cruz AMA’s (ADWR, 2009)

Water Use Data for GW Basins Water Use Data for GW Basins outside of AMA’s (ADWR, 2008 and outside of AMA’s (ADWR, 2008 and USGS, 2009)USGS, 2009)

Colorado River Basin Water Supply and Colorado River Basin Water Supply and Demand Study (Reclamation/CR Basin Demand Study (Reclamation/CR Basin States, in Draft)States, in Draft)

North Central Arizona Water Supply North Central Arizona Water Supply Study Report of Findings (Reclamation, Study Report of Findings (Reclamation, 2006)2006)

Augmentation Alternatives for the Augmentation Alternatives for the Sierra Vista Sub-watershed, Arizona, Sierra Vista Sub-watershed, Arizona, Appraisal Report (Reclamation, 2007)Appraisal Report (Reclamation, 2007)

Central Yavapai Highlands Water Central Yavapai Highlands Water Resources Management Study Resources Management Study (Reclamation, 2009)(Reclamation, 2009)

Existing Supply Data and StudiesExisting Supply Data and StudiesVulnerability/ Sustainability Vulnerability/ Sustainability

IssuesIssues Water Level Change Analysis for Arizona Water Level Change Analysis for Arizona

Water Atlas Vol. 9 (ADWR, in Draft)Water Atlas Vol. 9 (ADWR, in Draft) Recent Variability in Reservoir Levels and Recent Variability in Reservoir Levels and

Historic Changes in Precipitation from Historic Changes in Precipitation from Arizona Water Atlas Vol. 1 (ADWR, 2010 Arizona Water Atlas Vol. 1 (ADWR, 2010 revised)revised)

Vulnerability Assessment Categories, Criteria Vulnerability Assessment Categories, Criteria and Metrics for Arizona Water Atlas Vol. 9 and Metrics for Arizona Water Atlas Vol. 9 (ADWR, in Draft)(ADWR, in Draft)

Vulnerability assessment of climate-induced water shortage in Phoenix (Gober and Kirkwood, 2009)

Demand and Supply Assessments Demand and Supply Assessments for Phoenix, Tucson and Prescott for Phoenix, Tucson and Prescott

AMA’sAMA’s Historical Water Demand and Historical Water Demand and

Supply Water Characteristics for Supply Water Characteristics for 1985-20061985-2006

Multiple Demand and Supply Multiple Demand and Supply Projections out to 2025Projections out to 2025

Water Use Data for Pinal and Water Use Data for Pinal and Santa Cruz AMA’sSanta Cruz AMA’s

Historical Water Demand and Historical Water Demand and Supply Water Characteristics for Supply Water Characteristics for 1985-20061985-2006

Assessment Reports in DraftAssessment Reports in Draft

January 2009 version – subject to change

January 2009 version – subject to change

Water Use Data for GW Basins Water Use Data for GW Basins outside of AMA’soutside of AMA’s

GW Withdrawals (USGS, 2009) for 1991-2007GW Withdrawals (USGS, 2009) for 1991-2007

SW Diversions (ADWR, 2008) for 1991-2007SW Diversions (ADWR, 2008) for 1991-2007

Effluent Demand data from 13 basins c. 2005 Effluent Demand data from 13 basins c. 2005 (ADWR, 2009)(ADWR, 2009)

SectorSector # Basins with # Basins with DataData

MunicipalMunicipal 4646

AgriculturaAgriculturall

2626

IndustrialIndustrial 2727

SectorSector # Basins with # Basins with DataData

MunicipalMunicipal 1616

AgriculturaAgriculturall

1515

IndustrialIndustrial 88

Groundwater Groundwater Withdrawn for Withdrawn for Municipal DemandMunicipal Demand

46 GW Basins with 46 GW Basins with DataData

Surface Water Surface Water Diverted for Diverted for Agricultural Agricultural DemandDemand

15 GW Basins 15 GW Basins with Data with Data

Colorado River Basin Water Colorado River Basin Water Supply and Demand Study Supply and Demand Study

(Reclamation/CR Basin States, in (Reclamation/CR Basin States, in Draft)Draft)

Define current and future imbalances Define current and future imbalances in water supply and demandin water supply and demand (2010- (2010-2060)2060)

Geographic ScopeGeographic Scope Current Colorado River ContractorsCurrent Colorado River Contractors

MainstemMainstem Central ArizonaCentral Arizona

Other Rural AreasOther Rural Areas North Central ArizonaNorth Central Arizona Central Yavapai HighlandsCentral Yavapai Highlands Upper San PedroUpper San Pedro

Colorado River Basin Water Colorado River Basin Water Supply and Demand StudySupply and Demand Study

Unmet Demand = Unmet Demand =

Demand – (Locally Available Demand – (Locally Available Supplies)Supplies)

Locally Available Supplies have been Locally Available Supplies have been estimated for each of the areas of interestestimated for each of the areas of interest Mainstem: Current Colorado River Mainstem: Current Colorado River

EntitlementEntitlement Central Arizona: AMA Assessment DataCentral Arizona: AMA Assessment Data Other Rural Areas: Data from Reclamation Other Rural Areas: Data from Reclamation

StudiesStudies

Water Level Change Analysis for Water Level Change Analysis for Arizona Water Atlas Vol. 9 Arizona Water Atlas Vol. 9

(ADWR, in Draft)(ADWR, in Draft) Statistical data on groundwater level Statistical data on groundwater level

changes from the late 1980’s/early changes from the late 1980’s/early 1990’s to the mid to late 2000’s1990’s to the mid to late 2000’s

Water level change statistics Water level change statistics compiled for each groundwater compiled for each groundwater basin and subbasin in the statebasin and subbasin in the state

Accompanying map shows water Accompanying map shows water level changes (positive, negative, or level changes (positive, negative, or zero) over time periodzero) over time period

Count of Positive WL Changes 1513

Mean Positive WL Change 25.1 (Feet)

Mean Positive WL Change Rate 1.5 (Feet/year)

Median Positive WL Change 12.2 (Feet)

Count of Negative WL Changes 2842

Mean Negative WL Change -23.8 (Feet)

Mean Negative WL Change Rate -1.4 (Feet/year)

Median Negative WL Change -17.4 (Feet)

Count of All WL Changes 4396

Mean Of All WL Changes -6.7 (Feet)

Median Of All WL Changes -4.7 (Feet)

Summary of Statewide GW Level Summary of Statewide GW Level ChangesChanges

Recent Variability in Reservoir Recent Variability in Reservoir Levels and Historic Changes in Levels and Historic Changes in

Precipitation from Arizona Water Precipitation from Arizona Water Atlas Vol. 1Atlas Vol. 1

Reservoir Storage Volumes on Reservoir Storage Volumes on Colorado, Salt/Verde, and Gila Colorado, Salt/Verde, and Gila Rivers (1980-2008)Rivers (1980-2008)

Recent Variability in Reservoir Recent Variability in Reservoir Levels and Historic Changes in Levels and Historic Changes in

Precipitation from Arizona Water Precipitation from Arizona Water Atlas Vol. 1Atlas Vol. 1

Temperature and Precipitation Data Temperature and Precipitation Data by Planning Area (1930-2002) (non-by Planning Area (1930-2002) (non-AMA’s)AMA’s)

Recent Variability in Reservoir Recent Variability in Reservoir Levels and Historic Changes in Levels and Historic Changes in

Precipitation from Arizona Water Precipitation from Arizona Water Atlas Vol. 1Atlas Vol. 1

Winter Precipitation Departures from Winter Precipitation Departures from Average (1000-1988)Average (1000-1988)

Woodhouse et al. (2010) argue that Woodhouse et al. (2010) argue that the mid–12th-century drought, whose the mid–12th-century drought, whose severity and duration exceeded severity and duration exceeded anything in the historical record, can anything in the historical record, can be used to exemplify the severe be used to exemplify the severe droughts that may occur in the futuredroughts that may occur in the future

Vulnerability Assessment Vulnerability Assessment Categories, Criteria and Metrics Categories, Criteria and Metrics for Arizona Water Atlas Vol. 9 for Arizona Water Atlas Vol. 9

(ADWR, in Draft)(ADWR, in Draft) CategoriesCategories

A.A. Physical Supply ConstraintsPhysical Supply Constraints

B.B. Current Demand Exceeds SupplyCurrent Demand Exceeds Supply

C.C. Sensitivity to Extended Drought Sensitivity to Extended Drought or Shortageor Shortage

D.D. Legal ConsiderationsLegal Considerations

E.E. Environmental Impacts Environmental Impacts

Vulnerability Assessment Vulnerability Assessment Categories, Criteria and Metrics Categories, Criteria and Metrics

for Arizona Water Atlas Vol. 9for Arizona Water Atlas Vol. 9A) Physical Supply ConstraintsA) Physical Supply Constraints

A1A1 Dependency on non-renewable supplyDependency on non-renewable supplyA2A2 Groundwater is geologically limited Groundwater is geologically limited A3A3 Declining water levels in demand centers Declining water levels in demand centers A4 A4 Water Budget Deficit or Water Deficit Water Budget Deficit or Water Deficit AssessmentAssessmentA5A5 Insufficient infrastructure (current) Insufficient infrastructure (current) A6A6 Regional water quality exceedencesRegional water quality exceedencesA7 A7 Contamination restricts use as drinking Contamination restricts use as drinking water water suppliessuppliesA8A8 Groundwater data needsGroundwater data needs

Vulnerability Assessment Vulnerability Assessment Categories, Criteria and Metrics Categories, Criteria and Metrics

for Arizona Water Atlas Vol. 9for Arizona Water Atlas Vol. 9B) Current Demand Exceeds SupplyB) Current Demand Exceeds Supply

B1B1 Current high rate of growth Current high rate of growth B2B2 Meeting current demand has been Meeting current demand has been identified identified as a problem as a problem B3B3 Large number of inadequacy Large number of inadequacy determinations determinations (outside AMAs; all (outside AMAs; all reasons)reasons)B4 B4 Lack of a regional or local water Lack of a regional or local water resource resource management authority management authority B5 B5 Demand data are lacking in any given Demand data are lacking in any given sector sector (Environment, M&I or (Environment, M&I or Agriculture)Agriculture)

Vulnerability Assessment Vulnerability Assessment Categories, Criteria and Metrics Categories, Criteria and Metrics

for Arizona Water Atlas Vol. 9for Arizona Water Atlas Vol. 9C) Sensitivity to Extended Drought or C) Sensitivity to Extended Drought or

ShortageShortageC1 C1 Dependency on surface water or drought Dependency on surface water or drought

sensitive groundwater sensitive groundwater C2C2 Drought-caused supply problems in the pastDrought-caused supply problems in the pastC3C3 Insufficient long-term storage (dams, Insufficient long-term storage (dams,

recharge)recharge)C4C4 Weak Drought Preparedness (Community Weak Drought Preparedness (Community

Water System Drought Plan Water System Drought Plan Evaluation)Evaluation)C5C5 Historic drought trends/model predictions Historic drought trends/model predictions

show climate impactsshow climate impacts

Vulnerability Assessment Vulnerability Assessment Categories, Criteria and Metrics Categories, Criteria and Metrics

for Arizona Water Atlas Vol. 9for Arizona Water Atlas Vol. 9D) Legal Considerations D) Legal Considerations

D1D1 Low priority Colorado River Low priority Colorado River rightsrights

D2D2 Groundwater TransportationGroundwater Transportation

D3D3 Unquantified Federal Reserved Unquantified Federal Reserved Right Right ClaimsClaims

D4D4 Endangered species habitat Endangered species habitat impacts impacts access to supplyaccess to supply

Vulnerability Assessment Vulnerability Assessment Categories, Criteria and Metrics Categories, Criteria and Metrics

for Arizona Water Atlas Vol. 9for Arizona Water Atlas Vol. 9E) Environmental ValuesE) Environmental Values

E1 E1 Presence of a perennial/intermittent Presence of a perennial/intermittent stream in the basinstream in the basin

E2 E2 Potential for pumping to impact streamPotential for pumping to impact streamE3E3 Instream Flow rightsInstream Flow rightsE4E4 Subsidence (active or potential)Subsidence (active or potential)E5 E5 Impaired reaches affect use for Impaired reaches affect use for environmentenvironmentE6 E6 Environmental water needs identified as an Environmental water needs identified as an issueissueE7 E7 Unknown vulnerability (It is unknown what Unknown vulnerability (It is unknown what the the impacts of other sector’s demand will impacts of other sector’s demand will be on the be on the environment in a basin) environment in a basin)

Vulnerability Assessment of Vulnerability Assessment of Climate-Induced Water Shortage Climate-Induced Water Shortage in Phoenix (Gober and Kirkwood, in Phoenix (Gober and Kirkwood,

2009)2009) Published in Proceedings of the

National Academy of Sciences Uses a water-balance simulation

model to assess the vulnerability to long-term water shortage

Considers runoff scenarios for the Salt/Verde system (19% to 123% of historical mean) and mainstream of the Colorado River (61% to 118%)

Considered growth limits, land-use change and groundwater management strategies

Vulnerability Assessment of Vulnerability Assessment of Climate-Induced Water Shortage Climate-Induced Water Shortage in Phoenix (Gober and Kirkwood, in Phoenix (Gober and Kirkwood,

2009)2009) Results and Conclusions

Wide range of uncertainty about how much water will be available for from the Colorado and Salt/Verde systems

Designing a system to supply enough water for current consumption rates in the most pessimistic climate change scenarios would be very expensive and perhaps, physically impossible

Designing a system for a best guess case could leave vulnerable to water shortage with little time to adapt.