Title: California
1Californias Delta the fragility of the levee
system
- P. Joseph Grindstaff
- Director
- CALFED Bay-Delta Program
2What is the Delta?
- Largest estuary on Pacific Coast mixing zone
where - freshwater streams meet salty ocean surges
- Formed as states two
- largest rivers the
- Sacramento and San
- Joaquin join and
- flow west
- Comprised of 57
- islands and tracts
- Home to 750 species of
- wildlife and 400,000
- people
3Sacramento-San Joaquin Delta
4What is CALFED?
- A forum for Delta collaboration and problem
solving in open and accountable manner - Coordination of actions to
- create a healthy and
- balanced Delta on every
- front
- Water quality
- Water supply reliability
- Levee integrity
- Ecosystem health
- Protections and
- management of a vital, yet fragile system
- Key state and federal agencies working together
5CALFED Successes
- More than 500,000 acre-feet of new water
- Sacramento River salmon runs highest since the
1950s - Levees are being maintained, some levees are
stronger than before - Scientific information is used to improve
decision making - Debates occur and decisions are made in public
6But is that enough?
- There is still much more to do to ensure levees
are safe and strong - Levees are not the only issue facing the Delta
that needs immediate, prolonged attention for the
benefit of California - Like the canary in a mineshaft, levees are a
bellwether of the Deltas health
7Why is the Delta so important?
- Occupies 1 of states landmass, yet drains
nearly 40 of state - Provides some
- drinking water for
- 25 million statewide
- Fuels a 400 billion
- economy
- Irrigates 5 million acres of farmland vital to
states 31 billion agriculture economy that
supplies 45 of nations fruits and vegetables
8Why are Delta levees fragile?
- They are man-made from swamp land reclamation at
the turn of the century - The majority of its
- 1,100 miles of levees
- were made by farmers
- from material that is
- not stable by current
- standards described
- as piles of dirt
- The Delta is in a time
- and place where it is facing numerous challenges
9Flooding
- Flooding from winter
- storms is the most
- common and frequent
- Delta levee issue
10Historical Winter Flooding
- Flooding accounts for approximately 90 of all
natural disasters in California - A small percentage of winter flooding in
California is due to levee failures in the Delta - 1986 winter flooding resulted in levee break
- that inundated 4 Delta islands and flooded one
community - 1997 winter flooding caused several Delta levee
breaks and overtopping
11Immediate Impacts of Winter Storm Flooding
- Accelerated levee erosion
- Levee over-topping, burrowing, piping,
instability - Seepage, levee breaks
- Flooding of islands, resulting in property damage
and possibly - loss of life
- Dislocation of people, animals, wildlife
- Damage to ecosystem and water quality
- Disruption of water supply
12Longer-term Impacts of Winter Storm Flooding
- Several islands may be lost
- Repairs to levee system may be lengthy
- Water quality damage may be long-term, i.e.,
the Big - Gulp
- Economic damage to the area may be long term
13Problems More Complex than Flooding Alone
- Problems of extraordinary magnitude warrant a
solution of great proportions - Solution is bigger than one state agency or local
jurisdiction - It is more than water and levees or flooding
- We need a long-term vision for the Delta
14Need for a Delta Vision
- Current uses, resources and ecosystem of the
Delta are unsustainable - Changing environmental, hydrologic, climatic, and
land use conditions can jeopardize the Deltas
natural and human infrastructure - More holistic assessment and response strategies
are needed - CALFED will guide and be guided by Delta
Vision
15Many Separate Planning Efforts (selected)
Resources Uses gtgt Planning Efforts Land Use Planning Agriculture Transportation Utilities Urban Development Bay-Delta Ecosystem Flood Protection Water Conveyance Quality Air Quality Navigation Recreation Energy Local State Economy Emergency Services Law Enforcement
Delta Vision l l l l l l l l l l l l l l
AB 1200 and AB 1803 l l l l l l l l l
Delta Risk Management Study l l l l l l l l l l l
Delta Regional Ecosystem Restoration Implementation Plan l l l l l l l l l
Delta Protection Commission l l l l l l l l l l l l
16 l
Delta VisionOrganization Chart Draft 8-08-2006
Policy Technical Work Group Participants
17Delta Vision Work Group Topics
ParticipantsDraft August 8, 2006
Policy Technical Work Group Topics
Participants Topics Delta Scenarios
Strategies Agriculture, Land Use Housing
Transportation Utilities Environmental
Quality Protection Flood Risk Management
Water Conveyance Quality Local State
Economies Financing Strategies
Recreation Boating Emergency Services Law
Enforcement Participants
Blue Ribbon Panel Policy Resource Experts 7-9
Appointed Members
Stakeholder Coordination Committee
- Scientists Technical Experts
- Delta Risk Management Strategy
- Long-term Mgmt Strategy (LTMS)
- Delta Regional Ecosystem Restoration Implement
Plan - Bay Delta Conservation Plan
- SF Estuary Comprehensive Conservation Management
Plan - Suisun Marsh Charter Group
- Pelagic Organism Decline Team
- Global Climate Change Studies
- CALFED Science Program
- Interagency Ecological Program
- BTH Research Development
- Mercury Strategy for Bay-Delta
- Universities Research Institutes
- State Federal Agencies
- Delta Protection Commission
- CALFED Agency Directors (ELC)
- Dept. of Food Agriculture
- Dept. of Conservation
- Reclamation Board
- CALTRANS
- Housing Comm. Development
- Central and SF Regional WQCB
- Office of Emergency Services
- Dept. of Boating Waterways
- Dept. of Parks Recreation
- SF Bay Conservation Development Commission
- State Lands Commission
- Water Commission
- Others
- Local Government, Stakeholders Public
- County city governments
- In-Delta Interests Agriculture, Communities,
Business, Environment, Water quality,
Recreation, Boating, etc. - CA county farm bureaus and agricultural
commissioners - Regional planning organizations
- Transportation, Shipping, Utilities
- Water agencies and associations
- Environmental organizations
- Business building industry
- Reclamation districts
- Conservation districts
- Environmental Justice orgs.
- Tribes
- Other
18Purpose
- Meet the requirements of Assembly Bill 1200 AB
1803 - Encompass and integrate many separate planning
efforts - Assess the risks and consequences of
Business-As-Usual - Prepare Delta contingency and emergency response
plan - Develop a durable long-term Delta vision for
sustainable management of the Delta - Develop recommended options for public policy,
resource management, levee maintenance, and
funding strategies - Inform future Delta and Suisun planning decisions
19Products Schedule
Due Date
Delta Vision Work Plan August 2006
Delta Stakeholder Assessment Report September2006
Delta-Suisun Status Trends Assessment Report November 2006
Draft Delta Risk Assessment Report March 2007
Draft Delta Vision Report w/ Initial Blue Ribbon Task Force Recommendations June 2007
Final Delta Vision Report w/ Final Blue Ribbon Task Force Recommendations January 2008
Final Delta Strategic Plan (implementation) w/ Final Blue Ribbon Task Force Recommendations December 2008
20What do we want from Delta Vision?
- A public process that leads to substantial
agreement on recommendations for - The Deltas multiple uses over the next 100 years
- Public policies and resource management
strategies that will get us there - A near-term (25-50 years) contingency and
emergency plan for a catastrophic event in the
Delta
21Other Current Delta Initiatives
- Ongoing levee subvention program
- Emergency erosion repairs
- Bay-Delta Conservation Plan for Delta and its
tributaries - Delta Risk Management Study
- End of Stage 1/Beginning of Stage 2 actions
22Other Delta Levee Threats
- Earthquakes
- Climate change effects
- Land use
- Erosion, subsidence
23- Earthquakes
- Delta is east of many active Bay Area
- earthquake faults
CRCV
Green Valley
Rodgers Creek
Napa
Clayton
San Andreas
Concord Hayward
Verona
CRCV
Marsh Creek
Calaveras
24 Hypothetical Scenario
- A 6.5 magnitude earthquake
- in the western Delta
- 30 levee breaks
- 16 islands flooded
- Water quality degraded
- 200 miles of levees weakened by slumping,
cracking and increased seepage - Increased pressure on system leads to additional
levee failures
25- Levees Still Vulnerable
- Original estimate for PL84-99 levee
- improvements was 1.3 billion
- Levees remain susceptible to earthquakes even
after PL84-99 improvements are made
PL84-99 Levee Improvements
LEVEE FILL UNCOMPACTED PEAT AND LIQUEFIABLE SOILS
PEAT
LIQUEFIABLE SANDY AND SILTY SOILS
INTERLAYERED SANDS, SILTS, AND CLAYS
26Earthquake Animation
LEVEE FILL UNCOMPACTED PEAT AND LIQUIFIABLE SOILS
PEAT
LIQUEFIABLE SANDY AND SILTY SOILS
INTERLAYERED SANDS, SILTS, AND CLAYS
27- When Delta Levees Fail
- The Big Gulp
- 300 billion gallons of salt water flow
- into the Delta in
- first few days
28Delta Infrastructure at Risk
29- Long-term Impacts on
- Deltas Natural Resources
- After 18 months, much
- of the central Delta is a
- brackish waterway, with
- remnant levees.
- Unknown environmental
- impacts to Delta
- ecosystem
- Recreation is greatly reduced
30Long-term Costs To Californias Economy
- The Delta has been modified to deliver lesser
quality San Joaquin River water at lower amounts - Water treatment costs remain high due to
increased salinity and carbon content - Agriculture is greatly impacted throughout the
Delta and the state - Traffic in and around the Bay-Delta region
remains significantly impacted - Many Delta-area businesses are greatly impacted
and some close - Total costs to the states economy could be up to
30 billion in first 5 years - Total job loss exceeds 30,000
31Climate Change Effects
- Global warming will put the Delta at risk for
flooding as sea levels rise and hydrology
patterns change.
32What are we talking about?
- Increased temperatures
- - Earlier snow melt
- - Loss of snow pack as storage
- - Increased evaporation losses
- - Increased water temperatures
- Changes in weather patterns
- - Less precipitation falling as snow
- - Changes in water demand
- - Changes in watershed vegetation and runoff
- Sea level rise DWR Climate Change Report
http//baydeltaoffice.water.ca.gov/climate - change/DWRClimateChangeJuly06.pdf
33Snow pack as snow melt
- The estimated loss of Sierra
- snow pack resulting from a 3
- Celsius temperature rise over
- the next century is equivalent
- to the storage capacity of
- Lake Shasta!
34Sea Level Rise
2 ft.
Projections
1 ft.
Source IPCC, 2001
35Implications of Rising Sea Level for the Delta
Four?
Increasing threat of salinity intrusion,
backwater effects, habitat changes/loss, levee
failure, inundation, etc.
The Delta Changes
Two?
Feet of Rise
One?
36Land Use
- Rapid residential
- development rings
- Deltas east, west and
- southern boundaries
37South Delta Residential Growth Boom
- Tracy 28,000 homes under construction or planned
- Mountain House 16,000 homes under construction
- Lathrop 20,000 homes under construction or
planned - Manteca 14,000 homes under construction
- San Joaquin County 87,200 homes under
construction in south county, including 9,200
homes in West Stockton completed, under
construction or planned - Contra Costa County 75,000 homes under
construction or planned, including possibly 4,000
homes in Discovery Bay, with proposals
anticipated for Oakley, Antioch and Pittsburgh.
More than 5,000 homes completed in Brentwood
since 1999.
38Development Impacts Levees
- Places more pressure on aging levees
- Developers improvement of some levees may put
pressure on others - Development and increasing population density
will put more pressure on levees as traffic and
recreational usage increases
39Erosion, Subsidence
- Aging levees are subject
- to erosion due to their
- construction, the elements
- and hydrology
40Levee Subsidence
Graphic courtesy of Dr. Jeffrey Mount
41In Summary
- Delta levees are fragile and are not engineered
structures - They are susceptible to many challenges
- Historically, state and federal levee funds have
not been adequate for repairs and rehabilitation - Significant recommendations on the future of the
Delta are pending - End of Stage 1 12/06
- Draft Delta Risk Management Study 3/07
- Delta Vision 12/08
42Questions?
43For Copies of this Presentation,
- Contact Pat Rogers
- CALFED Bay-Delta Program
- progers_at_calwater.ca.gov