Climate Change and the Bay-Delta Conservation Plan Deirdre Des - - PowerPoint PPT Presentation

Climate Change and the Bay-Delta Conservation Plan Deirdre Des Jardins California Water Research Sierra Club California Water Committee

Recent drought in Southwest

➲ 2011-12: 500-1000 year drought in Texas ➲ 2012-13: 500-1000 year drought in New Mexico ➲ 2013-14: 500 year drought in California

Drought and Climate Change

➲ Many climate change models predict significant drying in

Southwest & Sierra Nevada mountains by mid-century

➲ Huge risk of increase in frequency and severity of droughts

➲

NOAA snowpack Jan 2014

Drier Climate Change Models

➲ Example: US Geological Survey, California Water Science

Center, Randy Hanson et. al. 2012

➲ Global Fluid Dynamics Lab GCM model (used in 2006, 2009,

& 2012 California Climate Adaptation Strategy modelling)

➲ A2 greenhouse gas scenario (medium-high emissions) ➲ Forecasts 17% reduction in Sacramento River flows by 2030

and 34% by 2080

➲

R.T. Hanson, L. E. Flint, A. L. Flint, et. al., , A method for physically based model analysis of conjunctive use in response to potential climate changes, Water Re- sources Research, v. 48

Projected reduction in Sacramento River flows

(R. Hanson et. al. 2012)

Change in frequency of wet & dry years

(R. Hanson et. al. 2012)

California Climate Change Adaptation Strategy climate models predict significant drying Sarah Null and Josh Viers, UC Davis, 2012

➲ Six Global Climate models used for the state of California 2012

Climate Change Adaptation Strategy modelling, two GHG sce- narios (low & medium-high)

➲ All 12 projections showed a significant increase in dry and criti-

cally dry years by the end of the century

➲ Almost all models also showed significant decrease in wet

years

Sarah Null and Josh Viers, Water and Energy Sector Vulnerability to Climate Warming in the Sierra Nevada: Water Year Classification in Non-Stationary Climates, CEC White Pa- per, July 2012.

Decrease in wet years and increase in dry & critically dry years for almost all models by midcentury

(Null & Viers 2012)

Change in Wet & Dry years averaged over all 6 GCM models

(Null & Viers 2012)

Bay Delta Conservation Plan climate change modelling

➲ Uses projections from 115 Global Climate Model / Greenhouse

Gas Emissions scenario combinations (Lawrence Livermore National Lab)

➲ Classifies 115 GCM / scenario climate projections into “more

warming, less warming” and “more drying, less drying”

➲ Forecasts 13-15% reduction in Sacramento River flows under

drier scenarios

BDCP classification: 115 GCM / scenarios

➲ Q1: Drier, less warming ➲ Q2: Drier, morewarming ➲ Q3: Wetter, more warming ➲ Q4: Wetter, less warming

BDCP ensemble models: Feather River

BDCP forecast change in inflow to reservoirs

BDCP wetter & drier climate change forecasts not published

➲ Only released internally to BDCP Steering Committee ➲ Not included in any of BDCP EIR drafts ➲ Not discussed at any BDCP public meetings

 What does BDCP EIR use for water delivery forecasts?

➲ “Central Tendency” projection ➲ Throws out 50% of drier models and 50% of wetter models,

then averages projections of remaining models

➲ Essentially assumes wetter & drier futures equally likely ➲ Disguises risk to water deliveries

Example: Feather River flows

BDCP & Reservoirs

➲ BDCP relies on South Delta pumps in dry years ➲ BDCP EIR water delivery forecasts assume draining Shasta,

Trinity, & Folsom reservoirs to minimum pool to meet export targets

Shasta reservoir repeatedly drained to minimum pool in repeat of 87-92 drought

BDCP & Sea Level Rise

➲ BDCP EIR does not model performance of tunnels under high

levels of sea level rise

➲ EIR uses value of 18 inches for sea level rise ➲ Even with tunnels, salinity intrusion could drastically curtail ex-

ports by 2100

➲ Tunnels may at best be a short term solution

US Army Corps of Engineers Modelling

1.68 m sea level rise (high value for 2100)

We can do better

➲ For the Sacramento Delta and San Francisco Bay ➲ For salmon and pelagic fish in the Delta ➲ For migrating birds

Sierra Club Alternative

➲ Accept peak water and environmental limits ➲ Reduce risk to economy and environment by investing in local

water efficiency and water reuse

➲ Focus on sustainability and environmental stewardship ➲ New growth needs to come from reductions elsewhere ➲ Most cost-effective and least energy-intensive alternative

Urban Water Conservation

➲ Big savings could be achieved by replacing thirsty lawns and

plantings with low-water landscape, installing smart irrigation technology, and utilizing rainwater and greywater

➲ More consumer education campaigns and aggressive rebate

programs for more efficient appliances

Major Investments in Repairs

➲ About 10% of urban water is lost through leaks in aging distri-

bution infrastructure, wasting energy as well as precious sup- plies

➲ New technology allows more efficient location and repair of

leaks

Water meters, detailed usage reports and tiered rates

➲ Tiered water rates, drought rates, and home usage reports give

customers detailed feedback and an incentive to conserve

➲ Eliminate fixed rates for all large landscapes, expand meters to

all dwellings in state

➲ Use separate meters in multi-family housing and separate me-

ters for landscaping to increase data and billing options

Urban water recycling

➲ In 2009, DWR estimated that recycling municipal wastewater

could save up to 2.3 million acre-feet

➲ Some California cities already use recycled water for aquifer

recharge, which helps make the strategy more affordable and less resource intensive

Agricultural water efficiency

➲ Agriculture uses 75 percent of California’s water ➲ Agricultural conservation strategies—including weather-based

irrigation controllers, drip irrigation and climate-appropriate crop selection—could yield over 3.4 million acre-feet in water sav- ings

Managing groundwater sustainably

➲ California is one of the few states in the nation that does

not regulate groundwater

➲ Failure to coordinate and moderate groundwater use has

led to unsustainable levels of overdraft

For More Information

➲ The entire text of Sierra Club California’s Sustainable Al-

ternatives policy paper can be accessed online: http://california2.sierraclub.org

➲ California Water Research

http://h20research.com/