Transcript December Basin Study Update

WESTCAPS Basin Study Planning Meeting
December 1-2, 2014, Phoenix, AZ
Water Resources Planning and Operations Support Group
Technical Service Center, Denver, Colorado
Background
•
Public Law 111-11, Subtitle F (SECURE
Water Act, SWA, 2009) § 9503.
•
Climate change risks for water and
environmental resources in “major
Reclamation river basins.”
•
Reclamation’s WaterSMART (Sustain
and Manage America’s Resources for
Tomorrow) program
1.
Basin Studies
2.
West-Wide Climate Risk Assessments
(WWCRAs)
3.
Landscape Conservation Cooperatives
(LCCs)
SECURE – Science and Engineering to Comprehensively
Understand and Responsibly Enhance
8 major Reclamation River Basin
WWCRA Activities
Downscaled BCSD CMIP-3 and CMIP-5
GCM Output and Hydrologic Modeling
(Bias-Correction Spatial Disaggregation - Coupled Model Intercomparison Project Phases 3 and 5 General Circulation Model)
Streamflow
Routing
Climate
Projections
Hydrology
Projections
Land
Surface
Simulation
Online Data Access
Climate and Hydrology Projections
http://gdo-dcp.ucllnl.org/downscaled_cmip_projections/dcpInterface.html
Basin Study Elements
Programmatic Requirements
•
Assessment of Water Supply
– Historic
– Future
•
Assessment of Water Demand
– Historic
– Future
•
Assessment of Water Supply-Demand Gaps (if any)
– Gap analysis
•
Options and Strategies to Address Water Supply-Demand Gaps (if any)
– System risk and reliability
•
Trade-off Analysis
– Identified options
Details at, http://www.usbr.gov/WaterSMART/bsp/require.html
Funded Basin Studies
2009
•
Colorado River Basin
•
Milk/St. Mary Rivers Basin
•
Yakima River Basin
2010
•
Niobrara River Basin
•
Truckee River Basin
•
Santa Ana River Basin
•
Henrys Fork of Snake River
•
S.E. California Regional Basin
2011
•
Lower Rio Grande River Basin
•
Santa Fe Basin
•
Klamath River Basin
•
Hood River Basin
2012
•
Upper Washita River Basin
•
Sacramento-San Joaquin Rivers
•
Republican River Basin
•
Pecos River Basin
•
L.A. Basin
2013, 2014… additional studies
For details please visit the Reclamation
Basin Studies website,
http://www.usbr.gov/WaterSMART/bsp/
Klamath River
Basin
Santa Ana River
Watershed
LEGEND
Basin Study
examples with
groundwater
component (later slides)
Example – Santa Ana River Watershed (Simple GW Tool)
Groundwater Availability
• Currently provides 54% of total water supply in an average year.
• Projected decreases in precipitation and increases in temperature will
decrease natural recharge.
• Groundwater use projected to increase.
SAWPA Groundwater
Screening Tool
SAWPA Groundwater
Screening Tool
• Will a 10% reduction in M&I
demand offset the impacts of
climate change in my groundwater
basin?
• What is the projected deficit in
groundwater storage in my basin by 2050
due to climate change?
SAWPA Groundwater
Screening Tool
– Example:
Orange County Coastal Plain Groundwater Basin
Estimated decline in
basin-averaged
groundwater levels
due to climate change
without management
actions to reduce
impacts
SAWPA Groundwater
Screening Tool
– Example:
Orange County Coastal Plain Groundwater Basin
Scenario Comparison: Management alternatives to offset
projected impacts on groundwater in Orange County
Conservation
Gradual reduction of
approx. 15% by 2020
(reduce per capita use from
~175 gpd to ~150 gpd)
Imported Water
Gradual increase in water
imports from Colorado
River and/or SWP
(increase from ~30,000
AF/yr to ~105,000 AF/yr
Example – Klamath River Basin Study (Complex GW Tool)
In summary, data selections and method choices are throughout the analysis…
II. Climate
Information
Providers:
“Here’s the info…
use it wisely.”
I. Decision-Makers:
“Keep it simple.”
III. Technical Practitioners:
“Keep it Manageable.”
… choices carry uncertainties, we need to understand those uncertainties, and
address them in the planning process .
West Salt River Valley Basin Study
Develop a strategy for integration of climate
change analysis into West Salt River Valley
Basin Study modeling efforts.
Climate Change Analysis Decisions
•
•
•
•
•
Historical period ,1950-1999
Future planning time horizon(s) – 1 (30-yr period centered around 2050, [2035-2064]
-> index sequential to 100-years for GW model runs)
Number of climate change scenarios - 3 (later slide), HD (hot-dry), CT (central-tendency), WW (warm-wet)
CMIP-5 Climate Projections per scenario – 10 (used in other Studies)
Variables
– Precipitation
– Temperature
– Recharge
•
•
How was recharge (mountain front) estimated historically in the GW model?
Model may not be sensitive to Mountain Front Recharge – hence, may not require adjustment under
climate change.
– Streamflow
•
•
•
•
Locations and how are stream boundary conditions represented in the GW models?
Temporal resolution – monthly to annual
Spatial domain and resolution (BCSD climate projection resolution, 1/8th-degree ~ 12 km)
Historical water supply and water demand - to be conducted by Study Partners
Example study questions from the Santa
Ana River Watershed Basin Study
• Will surface water supply (local) decrease?
• Will groundwater availability be reduced?
• Is Lake Elsinore in danger of drying up?
• Will the region continue to support an alpine
climate and how will the Jeffrey Pine ecosystem
be impacted?
Example study questions from the Santa
Ana River Watershed Basin Study
(cont’d…)
•
Will skiing at Big Bear Mountain Resorts be
sustained?
•
How many additional days over 95°F are expected
in Anaheim, Riverside and Big Bear City?
•
Will floods become more severe and threaten flood
infrastructure?
•
How will climate change and sea level rise affect
coastal communities and beaches?
Example Questions for
WESTCAPS Basin Study
• What is the potential for imported water supply to decrease?
– Trigger thresholds in Lake Mead, Colorado River Basin
Study
• What is the potential for increased groundwater pumping,
– due to reduced imported water supply?
– due to increased demand from population growth or
increased ag demand?
• What are the probabilities of violating the thresholds from GW
Management Act of 1980 (Assured Water Supply Act) across
the Basin?
Climate Change Scenarios
Note that the
values
adjacent to
each climate
change
scenario,
filled red
circles,
represent the
respective
percentiles
of
precipitation
and
temperature
changes
calculated
from the
projection
ensemble.