Transcript www.tceq.state.tx.us

Arizona Water Resources
and Issues
Border Governor’s
Conference - Water Table
May 8, 2006
Geographic and Socioeconomic
Profile
• Area and geographic boundaries
– 114,000 sq mi
– 6th largest state in U.S.
– Bordered on the south by Sonora, on west by
California and Baja California, on north by
Utah and on east by New Mexico
– Elevation range 70 feet – 12,633 feet
– 51 groundwater basins in Arizona
Geographic and Socioeconomic
Profile
• Population
– 15 counties; 87 cities and towns
– 5.9 million inhabitants (2005)
– 2nd fastest growing state in U.S.
• Socioeconomic conditions
– Principal activities: manufacturing, finance,
commerce, mining, agriculture, tourism
– 2.9 million employed (4.4% unemployment)
Hydrology
• Climate
– Characteristics: warm temperatures, aridity,
seasonal precipitation, high year-to-year variability,
strong decade-to-decade persistence
– Average annual rainfall ranges from 3 inches in
Yuma to >36 inches along Mogollon Rim
– Average daily temperatures range from mid 90s (F)
below 500 feet elevation to the high 50s (F) above
8,000 feet elevation
Average statewide Arizona monthly precipitation, (bars; left-hand
scale) and temperature (line; right-hand scale) 1971-2000
2.5
100
80
1.5
60
1
40
0.5
20
temp (F)
precip (in.)
2
0
0
jan
feb
mar
apr
may
jun
Precip (in.)
jul
aug
Temp (F)
sep
oct
nov
dec
Water Supply of Arizona
Colorado River
2.8 MAF
Salt River
0.9 MAF
Groundwater
3.5 MAF
Gila River 0.3
MAF
Hydrology
• Surface Water
– Colorado River Water 2.8 maf
• 1.3 maf on River
• 1.5 maf Central Arizona Project (CAP) to central Arizona
– Salt and Verde Rivers (Phoenix)
• 0.9 maf
– Gila River
• 0.3 maf
– Local surface water sources
• Little Colorado River, San Pedro River, Upper Verde River
Hydrology
• Groundwater
– Recharge rates vary significantly by area
– Deep, productive, good quality aquifers in many
areas of central and southern Arizona
– Thin, unproductive, deep or poor quality aquifers in
many systems in northern Arizona (Arsenic, Total
Dissolved Solids)
Arizona Water Supply
Annual Water Budget
Water Source
Million Acre-Feet (maf)
% of Total
SURFACE WATER
Colorado River
2.8
36.4 %
CAP
1.6
21%
On-River
1.2
16%
In-State Rivers
1.2
15.6%
Salt-Verde
0.9
12%
Gila & others
0.3
4%
GROUNDWATER
EFFLUENT
3.5
45.5%
0.18
2.3%
Total
7.7 maf
Arizona Reservoirs & Capacity
Reservoir
Capacity
(million AF)
Lake Powell
24.5
Lake Mead
25.9
Lake Mohave
1.8
Lake Havasu
0.65
Lake Pleasant
0.81
Horseshoe Lake
0.13
Bartlett Lake
0.18
Roosevelt Lake
1.6
San Carlos Lake
1.3
Apache Lake
0.25
Canyon Lake
0.06
Saguaro Lake
0.07
Alamo Lake
1.05
Reservoir Capacity
58.3 MAF
Arizona mean, high capacity and low capacity reservoir levels from
1971 through 2005, expressed in percent of total reservoir capacity
Average
Capacity
High
Capacity
High
Capacity
Year
Low
Capacity
(2004)
Colorado River System
Lake Powell
70%
98%
1983
31%
Colorado River System
Lake Mead
77%
98%
1983
51%
Colorado River System
Lake Mohave
89%
92%
2003
91%
Colorado River System
Lake Havasu
92%
94%
1995
91%
56%
91%
1992
43%
59%
77%
1979
43%
Reservoir Name
Verde River Basin System
Salt River Basin System
(2005)
Demand
Municipal
1.37 maf
18%
Industrial
.41 maf
5%
Agriculture
5.9 maf
77%
Sources: ADWR, UofA, USGS
Border Profile
• Two thirds of Arizona’s border is under federal
jurisdiction as national monuments, forests,
wildlife refuges, bombing ranges or are tribal
lands
• Significant agricultural and urban water use is
therefore restricted to area near Yuma and to
the communities of Nogales, Sierra Vista and
Douglas
Border Profile
Groundwater
Basin
2003
Population
2003
Surface
Water
Demand
(acre-ft)
2003
Groundwater
Demand
(acre-ft)
2050
Population
Yuma
176,000
788,000
304,000
502,000
Santa Cruz
AMA
37,000
Upper San
Pedro
82,000
4,500
34,000
110,000
Douglas
28,500
0
95,000
36,500
20,000
58,500
(2025)
Yuma Basin
Cultural Water Demand-2003
• 1.09 million acre-feet used in 2003 by agricultural,
municipal and industrial sector
– Well pumpage and diversion of Colorado River contract water
– 96% Agricultural Use
• Use not expected to increase
• 72% surface water
– 3.5% Municipal Use
• Rapidly growing communities of San Luis, Yuma and Fortuna
Foothills
• 85% surface water
– .5% Industrial Use
• 69% surface water
GROUNDWATER DATA FOR THE YUMA BASIN (DRAFT)
Basin Area, in square miles:
792
Name and/or Geologic Units
Major Aquifer(s):
Basin Fill
Range 3,186-5,271
Median 5,098
(3 well reported)
Measured by ADWR and/or USGS
Range 10-7,000
Median 2,456
(327 wells reported )
Reported on registration forms for
large (> 10-inch) diameter wells
Range 500-3,000
ADWR (1990)
Range 0-2,500
USGS (1994)
213,000
Freethey and Anderson (1986)
49,000,000 (to 1,200 ft bls)
ADWR (1994)
34,000,0001 (to 1,200 ft bls)
Freethey and Anderson (1986)
35,000,000 (to 1,200 ft bls)
Arizona Water Commission (1975)
Well Yields, in gal/min:
Estimated Natural Recharge,
in acre-feet/year:
Estimated Water Currently in Storage,
in acre-feet:
Current Number of Index Wells:
11
Date of Last Water-level Sweep:
1992 (587 wells measured)
Reported Water Quality Exceedences:
1Predevelopment
Estimate
bls=below land surface
Arsenic, Cadmium, Fluoride, Lead, Nitrate, Organics, Solids, and Trace
Elements (Antimony, Beryllium, and Thallium)
Santa Cruz AMA
Demographics
Amado
PIMA
SANTA
COUNTY
Tubac
CRUZ
COUNTY
Rio Rico
Nogales
• 37,000 people;
population concentrated
in Nogales and along
the Santa Cruz River
• Large fluctuations in
temporary residents
• Nogales, AZ population
23,000
• Nogales, Mexico
population 300,000
Santa Cruz AMA Demand
Use by Sector
All water uses
Underflow to
Tucson AMA
16%
8,600 AF
Agricultural
19%
10,300
Industrial
8%
AF
Municipal
13%
7,300 AF
Industrial
3%
1,500 AF
Riparian
48%
25,800 AF
Domestic
1%
537 AF
Municipal
40%
Agricultural
52%
Upper San Pedro Basin
Cultural Water Demand - 2003
20,000
18,000
Acre-Feet
16,000
14,000
12,000
Surface water
10,000
Groundwater
8,000
6,000
4,000
2,000
0
Municipal
Industrial
Agricultural
Water Use Sector
Douglas Basin
Cultural Water Demand - 2003
• 60,400 acre feet of groundwater
• Irrigation Non-expansion area
– Most of basin is an Irrigation Non-expansion area
– no new lands can be irrigated with groundwater
• 89% Agricultural Use
– Water use is increasing
• 11% Municipal Use
– Demand is increasing slowly
Government Framework and Management
of Water Resources
Laws governing surface water are distinct from those
governing groundwater
– Surface water
•Prior appropriation doctrine
– “First in time, first in right”
“Subflow”
subsurface water
subject to surface
water law
– Groundwater
•Beneficial use doctrine
– Unlimited ability to pump, so long as use is
“beneficial” and “reasonable” (outside AMAs)
– Ability to pump constrained by system of rights
and permits (inside AMAs)
Government Framework and Management
of Water Resources
• Federal Agencies
– Bureau of Reclamation
• Administers Colorado River Basin Project Act and Colorado River
Contracts.
• Responsible for construction of major water supply development
projects
– Environmental Protection Agency
• Federal oversight of surface water and drinking water quality
programs
• Oversight of state efforts to regulate solid waste landfills and
hazardous waste sites
– Army Corp of Engineers
• Conducts flood control studies and dam, levee and channelization
projects. Regulates placement of dredged or fill material into
waters of the U.S.
Government Framework and Management
of Water Resources
• State of Arizona Agencies
– Arizona Department of Water Resources
• Groundwater management and administration of water rights
• Technical and administrative support to the surface water
adjudication court
• Authority to consult, advise and cooperate with the U.S. Secretary
of Interior on certain matters related to the Colorado River
• Supervision of safety of dams under state jurisdiction
– Arizona Department of Environmental Quality
• Administers water pollution control, monitoring and assessment,
and contamination site cleanup programs
• Effluent reuse, groundwater recharge projects and discharge of
water to aquifers or streambeds must meet water quality
standards
Government Framework and Management
of Water Resources
• State of Arizona Agencies
– Central Arizona Water Conservation District
• Tax-levying public improvement district of the state
responsible for Central Arizona Project system
maintenance and operations, repayment obligations and
creation of water resource management programs
– Arizona Water Banking Authority
• Stores Arizona’s unused Colorado River allotment in
groundwater basins to firm up urban water supplies for
Arizona to be used during times of shortages on the
Colorado River or during CAP service interruptions.
• May enter into interstate agreements with entities in
Nevada and California to store water in Arizona
Government Framework and Management
of Water Resources
• Local Agencies
– Have certain authorities to obtain and manage
water resources locally in accordance with state and
federal laws
– Public water utilities
• Set water rates, can enact local water conservation and
water use ordinances. For example, can require effluent
use on golf courses, time of day lawn watering, etc.
– Private water utilities
• Regulated by the Arizona Corporation Commission, which
regulates water rates and authorizes curtailment tariffs
when demand is greater than production
• Cannot pass ordinances affecting water use or rates
Groundwater Management
• There are different programs and regulations in
Active Management Areas (AMAs), Irrigation
Non-Expansion areas (INAs) and in areas
outside of AMAs and INAs.
• Statewide, all wells must be registered and
drilled by a licensed well driller
• Statewide, transportation of groundwater
between groundwater basins is prohibited
except as allowed specifically by statute
Water Management Areas
Prescott AMA goal:
safe-yield by 2025
Harquahala INA: No
new irrigated lands
Pinal AMA goals:
- allow development of nonirrigation uses
- preserve agriculture as
long as feasible
Santa Cruz AMA goal:
- maintain safe-yield
- prevent decline of water table
Joseph City INA: No
new irrigated lands
Phoenix AMA goal:
safe-yield by 2025
Tucson AMA goal:
safe-yield by 2025
Douglas INA: No
new irrigated lands
Groundwater Management –
Active Management Areas
• 1980 Groundwater Management Act:
– Established Active Management Areas (AMA’s) – Currently 5
– Established a system of groundwater rights based on historic
use and permits for new uses subject to specific conditions
– Set long-range water management goals for AMAs
• Will AMAs achieve their goals? What other actions are needed?
• Requires management plan for each AMA
– Created the Arizona Department of Water Resources to
administer the provisions of the Act
• Department has regulatory, permitting and enforcement power; it
does not control water supplies or infrastructure
Groundwater Management –
AMA Management Plans
– New plan every 10 years, though
2025; developed through a
public process
– Increasingly stringent
conservation requirements
– Include long-range water
demand and supply projections
– Conservation programs for
agriculture, municipal and
industrial water users
– Recharge/augmentation
program and water quality
assessment
Groundwater Management –
Irrigation Non-Expansion Areas
• Irrigation non-expansion areas
– Established in areas of critical groundwater
overdraft-but not as severe as in AMAs
– Prohibition of new agricultural irrigation
acreage
– Management objective to protect existing
water users
– 3 INAs: Douglas, Harquahala, Joseph City
Challenges: Future Water Supplies
• Underground Storage
–
–
–
–
CAP and effluent
55 Active Permits
Permitted volumes 150 af to 200 kaf/year
Most recharge facilities are located within AMAs;
especially the Phoenix AMA
• Conservation
• Reuse
• Augmentation
Future Water Supplies
Underground Storage - Benefits
• Long-term storage
• Large capacity
• Little evaporative loss
• Reduces risk of
subsidence
Future Water Supplies-Conservation
• Public outreach:
• Teach Good Water Habits Statewide
• Provide information on the best available conservation
technologies
• Provide incentives – tax credits
• Voluntary local conservation goals
• Promote low water use designs in landscaping
• Local government initiatives:
• ‘Toilet to tap’
• Domestic/commercial water-harvesting and use of
‘graywater’
• Encourage water-efficient appliances, fixtures, ordinances
• Ordinances for use of effluent for large turf areas such as
golf courses, parks and sports facilities
Future Water Supplies - Effluent Reuse and
Augmentation
• Improve treatment quality or match quality to use
• Turf and Landscape Uses - some municipal and county
ordinances require effluent for new golf courses and turf
areas. There are also regulatory incentives
• Recharge excess for later recovery
• Direct Reuse – considered but must overcome public
perception issues
• Augmentation includes importing water where legally
available, cloud seeding, constructing necessary
infrastructure, securing water sources and rights,
desalination
Challenges: Indian Water Settlements
• 28% of Arizona Land held in Trust for the benefit of
Native Americans
• Many areas of the state are affected by Indian Water
Rights settlements with significant implications for
water management and access to water
• Recently Settled:
– Gila River Indian Community and Tohono O’odham
635,000 acre-feet/year to Gila River Indian Community
-- Fort Yuma – Quechan
• Pending settlements; Navajo, Hopi, White Mountain
Apache and San Carlos Apache
Challenges - Surface Water Adjudications
Definition: “A general stream adjudication is a
judicial proceeding in which the nature, extent,
and relative priority of water rights is
determined.”
Gila & Little Colorado cases are still in Phase 1
after 30+ years
Gila River
Little Colorado River
•Court must define the legal
difference between surface water and
ground water before rights can be
determined
Challenges - Colorado River
• Of the 7.5 million acre-feet of water available to the
lower basin states, Arizona’s Central Arizona Project
water supply has the most junior priority.
• River is over-allocated
•16.5 maf allocation vs. 13 - 15 maf actual
• Drought impacts on water supply
• Discussions are underway on supply augmentation,
conservation and system management to meet
demands and obligations
Colorado River Compact &
Treaty Allocations
Upper Basin (7.5 maf)
Lee Ferry
Lower Basin (7.5 maf)
California – 4.4 maf
Arizona – 2.8 maf
Nevada – 0.3 maf
Mexico 1.5 maf
Arizona
Upper
Basin –
50 kaf
Mexican Water Treaty of 1944
Allots to Mexico 1.5 maf of Colorado
River water per year, plus 200,000
acre-feet if the Secretary determines
that surplus water is available.
Colorado River Flows
Estimated past flow averages
18
Tree rings,
Upper Basin
(1512-1961)
Million Acre Feet
Lowest 20-year
average
(1579-1598)
Tree rings,
Upper Basin
(1512-2000)
10.95 MAF
14.7 MAF
12
10
Isotopes,
Delta clams
(1500-1950)
12.5 MAF
8
16.5 MAF
13.5 MAF
16
14
Legally
allocated
Challenges -Drought
• Arizona Drought Preparedness Plan
adopted in 2004 to identify drought
impacts, prepare drought response and
reduce drought impacts
• Water providers must prepare drought
plans
• Drought monitoring is ongoing
Average water year (October –September) temperature and total water-year
precipitation in Arizona from 1930-2002.
Figure Author: Ben Crawford, CLIMAS
Challenges - Border
• Issues related to the Colorado River are under federal
jurisdiction and international treaty
• Increasing population growth is impacting shared and
limited water supplies
• Limited hydrologic information for many border basins
hinders water planning and management
• Water quality issues in the Douglas/Agua Prieta and
Ambos Nogales pose a threat to local water supplies
• Lack of access to renewable water supplies to support
increasing demand
Challenges - Border
• Need for an integrated binational groundwater
model to effectively manage the Santa Cruz
AMA water resources to meet the management
goal
• Uncertainty about the future use of effluent
generated by Mexico and treated at the
Nogales International Wastewater treatment
plant in Arizona and concerns about the quality
of the effluent. Effluent is an important supply
for riparian areas and groundwater recharge