Climate Change Threat Drought 1

Potential Impacts from Drought How might our community be impacted by drought? 2

Drought Impacts: Reduced Groundwater Recharge 3

Adaptation Options for Reduced Groundwater Recharge Monitor groundwater conditions and incorporate climate change projections into groundwater models Build systems to recycle water for energy, industrial, agricultural or household use Update your drought contingency plan to identify triggers that would result in demand management activities Work with the agricultural industry to reduce water demand Establish regional interconnections 4

Adapting to Reduced Groundwater Recharge Example: Tucson, Arizona Tucson Water is almost completely dependent on groundwater sources Reduced precipitation in the future could place more strain on groundwater sources Tucson constructed a large scale recharge/recovery system for water from the Central Arizona Project (CAP) in the late 1990s Allocated water is used to recharge underground wells (can store almost 45,000 acre-feet of water per year for future use) Tucson projects reliable service through

Adapting to Reduced Groundwater Recharge (cont’d) Example: Tucson, Arizona Instituted new management actions: Plans to construct additional spreading basins and production wells to provide storage Incorporate these opportunities to local and regional CAP partners Implement its Recycled Water Program to make underutilized reclaimed water available to meet future potable needs 6

Drought Impacts: Lower Lake and Reservoir Levels 7

Adaptation Options for Lower Lake and Reservoir Levels Develop alternative water supplies or increase storage Build systems to recycle water for energy, industrial, agricultural or household use Retrofit intakes Establish regional interconnections Update your drought contingency plan to include triggers for when the utility will implement water demand management strategies Work with the agricultural industry to reduce water demand Increase monitoring activities 8

Adapting to Lower Lake and Reservoir Levels Example: Las Vegas, Nevada Southern Nevada Water Authority (SNWA) receives 90% of its water from one reservoir Lake Mead elevations have declined more than 100 ft. in the last decade (4 trillion gallon loss) Concerns include further reductions resulting from climate change Demand management practices implemented to reduce consumption (down 32% since 2000) Instituted new management actions: Infrastructure enhancements (Completion of second intake, ongoing construction of a deeper intake and additional water treatment capacity using ozone) 9

Extreme Event Example: 2002 Drought – More than 30 U.S. States 10

Drought Impacts: Volume and Temperature Changes 11

Adaptation Options for Volume and Temperature Changes Model potential changes in water quality and determine costs of treatment changes. Update drought contingency plans Monitor surface water conditions Diversify water supply through using recycled water, desalination, stormwater capture and conjunctive use (using groundwater and surface water) Increase treatment capabilities 12

Adapting to Volume and Temperature Changes Example: Portland Water Bureau, Oregon Primary source is surface water; secondary source is groundwater Precipitation ranges between 59 and 80 inches per year, falling mostly during the winter months Greatest challenge is meeting summer demand Climate and regional growth models project increased winter precipitation, earlier snowmelt and drier summers, coupled with continued population growth 13

Adapting to Volume and Temperature Changes (cont’d) Example: Portland Water Bureau, Oregon Seasonal changes in runoff are anticipated and are of major concern: 15% increase in spring runoff 30% reduction in late spring runoff Increased demand during summer months will decrease reservoir storage Adaptation strategies Augment supply by expanding groundwater resources and surface water storage Practice conjunctive use strategies (Such as aquifer storage and recovery) 14

Extreme Event: July 2011 Drought Texas, Oklahoma, Arizona, Southern Kansas and Western Louisiana 15

Drought Impacts: Altered Surface Water Quality 16

Adaptation Options for Altered Surface Water Quality Monitor water quality in receiving bodies Finance and facilitate systems to recycle water to decrease discharges to receiving waters Work with regulatory agencies to discuss regulatory options for compliance Increase treatment capabilities 17

Drought Impacts: Increased Fire Risk and Altered Vegetation 18

Adaptation Options for Increased Fire Risk and Altered Vegetation Update fire management plans and increase fire management activities (thinning, weed control, controlled burns, create fire breaks) Update emergency response plans Increase treatment capabilities Monitor surface water conditions Establish alternative power supplies to support operations in the event of power loss. Join a mutual aid network, such as WARN (Water and Wastewater Agency Response Network) 19

Adapting to Increased Fire Risk and Altered Vegetation Example: Denver, CO 1996 Buffalo Creek Fire (11,900 acres) and 2002 Hayman Fire (138,000 acres) occurred directly upstream from the Strontia Springs Reservoir Flash floods washed 1 million cubic yards of sediment into the reservoir, adding to the 250,000 cubic yards currently in the reservoir Hayman fire led to loss of 600 structures; total insured private property losses were estimated at $38.7 million 20

Adapting to Increased Fire Risk and Altered Vegetation (cont’d) Example: Denver, CO Denver Water spent more than $26 million on water quality treatment, sediment and debris removal, reclamation techniques and infrastructure projects Adaptation strategies Shared investment of $33 million between Denver Water and U.S. Forest Service Rocky Mountain Region for restoration projects exceeding 38,000 acres Work will include mechanical thinning, fuel reduction, construction of fire breaks, erosion control, decommissioning of roads and reforestation 21

Community and Economic Impacts from Drought Service disruptions can cause customers to lose confidence in their utility’s ability to provide clean and safe water to customers Local businesses suffer and may lose revenue if they lack reliable access to water or sewer services What can be done? Collaborate with other community partners to develop more sustainable community and regional plans Discuss adaptation options with local businesses Work with local government to communicate adaptation activities and plans to customers 22