Water Resources 101 Arizona’s Water: Supplies and Usage

Water Resources 101 Where does Arizona’s water come from? Three basic sources: 1. Groundwater 2. Surface Water 3. Effluent

Water Resources 101 Groundwater Farmers in Tucson area began drilling GW wells in early 1900’s 1902: DTW 10’-20’ 1922: DTW ~ 100’ 2006: DTW ~ 300’ There are now ~ 7,000 production wells in AZ (without private wells)

Water Resources 101 Groundwater Use in AZ Total GW Pumpage in 2005 was 2.9 MAF Accounts for approximately 40% of AZ’s water supply Groundwater mining (overdraft) is a statewide problem – its not just for AMA’s anymore Tucson AMA 220 KAF Phoenix AMA 800 KAF Pinal AMA 460 KAF Santa Cruz AMA 21 KAF Non AMA Areas 1.4 MAF Prescott AMA 21 KAF 2005 Data

Water Resources 101 Surface Water History: Pre-Hohokam irrigation system found in Tucson – 1200 BC Hohokam developed first canal in Phoenix area in 800 AD AZ’s largest source of renewable water About 50% of AZ’s water supply Over 4 MAF per year Availability varies from: year to year season to season place to place 2005 Data Colorado River 2.8 MAF Gila River 0.4 MAF Salt/Verde River 1.0 MAF

Water Resources 101 Salt River Project (SRP) 1902 – National Reclamation Act (Provided funding for SRP) 1903 – SRP established: 1 st multipurpose reclamation project in the US (water & power) 1908 – Granite Reef Diversion completed 1911 – Roosevelt Dam Completed (later expanded in 1996) From 1925 – 1946 SRP built 5 more dams 3 on the Salt River 2 on the Verde River Total capacity ~ 2.3MAF delivered ~ 1MAF of water 80% Ag in 1965 – 15% Ag in 2007

Water Resources – Boulder Canyon Project Act (Allocated Colo. River Water) 1946 – Formation of CAPA (Lobbying group for CAP) 1968 – Colorado River Basin Project Act (CAP Authorization) 1973 – Construction started 1993 – Project completion 335 miles, 2,400’ lift 1.6 MAF/yr of deliveries (26% Ag in 2008) Construction cost >$4 billion Largest water transfer project ever constructed in the US Central Arizona Project (CAP)

Water Resources 101 Effluent Long history of reuse in AZ Grand Canyon – 1926 Phoenix/Peterson Farms – 1932 Tucson Reclaimed System Direct reuse accounts for ~ 2.5% of AZ’s water supply (200 KAF) ~ 70% for turf/ag irrigation In 2006, we directly reused about 20% of the effluent produced in AZ Probably higher in 2008 Remainder is recharged – directly & indirectly

Water Resources 101 How Is Arizona’s Water Used? Agriculture 74% 5.8 MAF Industrial 6% Municipal 20% 1.6 MAF 0.5 MAF 2005 Data Total Water Usage = 7.9 MAF

Water Resources 101 How Has Our Water Use Changed Over Time? In general, water consumption has increased with increasing populations (except recent AMA activity) Water use between sectors has changed Use between water sources has shifted Water use changes vary by geographical region

Water Resources 101 The AZ Water Atlas ADWR project – overview of water supply and demand in Arizona Divides state into 7 Planning Areas When complete – 8 Volumes Goal – Provide regional perspective on supply, demand and water resource issues

Water Resources 101 Active Management Areas (AMAs)

Water Resources 101 Tucson AMA Changes By Sector 1986 By Source KAF 344 KAF 518K People 1.0M People * GSF = 100% CAP *

Water Resources Tucson Active Management Area Water Use by Sector:

Water Resources 101 Phoenix AMA Changes By Sector 1986 By Source MAF 1.9M People 3.6M People * GSF = 80% CAP/20% Effluent *

Water Resources 101 Pinal AMA Changes By Sector 1986 By Source KAF 1.0 MAF 40K People 148K Ppl * GSF = 100% CAP *

Water Resources 101 Prescott AMA Changes By SectorBy Source KAF 46 KAF 40K Ppl 95K People

Water Resources 101 Santa Cruz AMA Changes By Source By Sector 21 KAF16 KAF 19K People22K People

Water Resources 101 Eastern Plateau Planning Area

Water Resources 101 Eastern Plateau Planning Area GW use increased by 13% from 1986 to 2005 SW use decreased by 40% from 1986 to 2005 Water Use by Sector: Industrial = 49% Municipal = 26% Agricultural = 25% Population increased from 209K in 1990 to 279K in 2006 (33%) 61% 9% 30% Average Annual Water Use per Sector ( ) Total ~ 170 KAF

Water Resources 101 Southeastern AZ Planning Area

Water Resources 101 Southeastern AZ Planning Area Water Use by Sector AG 85% Muni 8% Ind 7% Total Water Use ( ) = 515,000 AF/YR Agricultural demand increased by 4% from 1995 – 2005 Industrial demand decreased by 38% from 1995 – 2005 Effluent reuse < 1% of total water use (11% of total amount generated) Groundwater use accounts for about 84% of total water use

Water Resources 101 Upper Colorado River Planning Area

Water Resources 101 Upper Colorado River Planning Area Water Use by Sector (2003): SW 38% Effluent 2% GW 60% Water Use By Source (2003) Total Water Use (2003) = 173,650 AF Agricultural = 95,850 AF (55%) Municipal = 55,200 AF (32%) Industrial = 22,600 AF (13%)

Water Resources 101 Central Highlands Planning Area

Water Resources 101 Central Highlands Planning Area Water Use by Sector (2003): SW 38% Effluent 2% GW 60% Water Use By Source (2001 – 2003) Total Water Use (2003) = 77,650 AF Agricultural = 38,000 AF (49%) Municipal = 22,600 AF (29%)  92% GW Industrial = 17,100 AF (22%)

Water Resources 101 Western Plateau Planning Area

Water Resources 101 Western Plateau Planning Area Water Use by Sector: Agricultural = 4,500 AF (51%)  44% from GW Municipal = 3,400 AF (39%) Industrial = 900 AF (10%) Water Use By Source ( ) SW 39% Effluent 3% GW 57% Total Water Use = 8,800 AF

Water Resources 101 Lower Colorado River Planning Area

Water Resources 101 Lower Colorado River Planning Area Water Use by Source: Groundwater = 1,027,250 AF (34%) Surface Water = 2,010,500 AF (66%)  CAP = 88,187 AF Effluent = 680 AF (0.02%) Water Use By Sector ( ) Total Water Use = 3,038,400 AF Agriculture 98% Municipal 2% Industrial <1%

Water Resources 101 So, What Have We Learned? Water Use Patterns have changed over time: by Sector by Source by Geography Conjunctive use Works! Diversity is a good thing! Combination varies by region, but sources are the same: Groundwater Surface Water Effluent Planning (Long-Term) + Investment = Reliability