climate change and water supply prioritization

Climate Change & Water Supply Prioritization

Taking it for Granted

• “We never know the worth of water till the well is dry”- Thomas Fuller, 1732

70% of the earth’s surface is covered in water.

The human body is 72% water.

Beer is 95% water

Climate Change Impacts on Drought

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The Water-Energy Nexus

•What is the “Water-Energy Nexus”?• Energy needed to extract, convey, treat, deliver, and heat

potable water.• “Embedded energy”

• Currently, water-related energy use in California consumes approximately 20 of the state’s electricity.

The Water(-Energy) CycleClimate Change, Drought, and the Water-Energy Nexus

• Prolonged/More Intense Drought Conditions• Reduced water supply• Irregularity becoming more regular• Unreliable

• Water-Energy Cycle • Additional potential water supplies are energy intense• More GHGs resulting from increased energy usage• Increased GHGs exacerbate climate change

Breaking the Water-Energy Cycle in San Diego

High Energy Water Sources

More Greenhouse Gases

More Frequent, More Intense Drought Conditions

“Demand” for Additional Water

California’s Water & Energy Conservation Mandates

•Greenhouse gases•AB32: Cut CA greenhouse gas emissions to 1990

levels by 2025, and then cut to 80% below 1990 levels by 2050.

•Water•20% reduction in water use by the year 2020.

California’s Strategy to Meet Goals

• “A conservation-first policy for water-sector investment and action would help to sustain declining per-capita usage. This policy would be similar to the State’s “loading order” policy for energy, which prioritizes investments in energy efficiency ahead of developing new power supplies.” (CA Climate Change Scoping Plan)

• Loading orders prioritize efficiency, lessened demand, and renewables/recyclables, over new energy-intense sources.

San Diego’s Water Loading Order

• Conservation - REDUCE• 60-70% used outside homes• Adopt localized landscapes• Aggressive Conservation Measures

• Capture and Use - REUSE• Rain barrels, cisterns, catchment areas, green infrastructure• Distributed technologies

• Recycling - RECYCLE• Large scale (Pt. Loma, Orange County)• Small scale (grey water, etc.)

More Energy-Intense Loading Order Options

• Imported Water• Unreliable• Subject to increasing climate change impacts/drought• Less local water security/control• Expensive• Water evaporative losses in conveyance

• Desalination• Very expensive• Environmentally harmful with current technology (GHGs, entrainment,

impingement)

Our Current Use

•Use per person per day – Approximately 150 gallons per day per capita in San Diego

•Up to 70% of residential water used in Southern California is used outdoors.

Quick Lessons from Australia

•Australia Use – Approx 60 gallons per capita per day

• San Diego Use – Approx 150 gallons per capita per day

•Recent Pacific Institute and NRDC findings •Residential can cut use between 40-60%.•Businesses and industry can cut use 30-60%.

San Diego Solutions to Breaking the Cycle

• Integrated water management solutions• Reduce demand & capture and use stormwater through Low Impact Development

and Green Infrastructure

• Diversified and resilient supply grounded first on conservation, capture/use, and recycling

• We can exceed 20% reductions by 2020 water use goals and meet or exceed GHG goals of statewide laws

• Save money by delaying or eliminating need for additional expensive and energy-intense sources

Conservation Strategies

• Localized landscape subsidies or mandates• Turf prohibitions on new development and/or

redevelopment• Irrigation Mandates – Scheduled Irrigation• Pricing that incentivizes conservation and dis-incentivizes

water waste• Cut leaks and losses in underground pipes through

infrastructure maintenance and upgrades

Localized Landscapes

Capture and Use Strategies• Stormwater capture and use strategies

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Recycling StrategiesPotable Reuse

Laundry to Landscape

A Resilient Water-Energy Cycle for San Diego

Capture/Use, Recycling Sources for Remaining Needs

Reduction or Stabilization of Greenhouse Gas Emissions Reduced Demand Response Through Conservation

Climate Change Impacts

SAN DIEGO COASTKEEPER

www.sdcoastkeeper.org

Protecting and Restoring Fishable, Swimmable, Drinkable Waters in San Diego County