Las Vegas adaptation policies at a glance
Covering approximately 650 km² with around 650,000 inhabitants, Las Vegas is located in a vast desert valley in the far south of Nevada, surrounded by mountains rising to 3000 metres, and drawing 90% of its water from the Colorado River. The city is part of an extended urban area that covers two counties making up a territory of 67,487 km² with 2 million inhabitants. The hot desert climate consists of a dry and very hot summer season and a short winter season. Due to its geographical location, population and activity needs, the water supply that depends on Lake Mead is increasingly difficult. Las Vegas is one of the three cities that reported the most adaptation actions to the Carbon Disclosure Project (CDP).
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The Southern Nevada Water Authority (SNWA) is an agency that was created in 1991 to manage the water needs of southern Nevada. Comprising seven water agencies, SNWA is responsible for the treatment, distribution and management of water resources in the short and long term for southern Nevada. As a member of the Environmental Protection Agency’s (EPA) Creating Resilient Water Utilities programme, SNWA conducted a vulnerability analysis of Las Vegas to the climate impacts of two selected scenarios (2035 and 2060) on which its Water Resource Plan published in 2018 is based. Several levels of government help Las Vegas with water supply: at the county level, the Clark County Multi-Jurisdictional Hazard Mitigation Plan, the Nevada State Drought Plan and Enhanced Hazard Mitigation Plan, and the Department of the Interior’s WaterSMART programme.
The approach used has been to highlight the solutions proposed by the institutional actors responsible for water management and their technical partners. The vulnerability analysis conducted by the SNWA identified more than 60 potential actions to address the impacts of climate change, while assessing the availability of the resource in relation to its future demand. The methodology used for this analysis was inspired by several tools made available by the EPA, namely the Climate Resilience Assessment and Awareness Tool (CREAT), the Adaptation Strategies Guide and the Hydrologic and Water Quality System modelling platform.
- Water demand exceeds river supply (Lake Mead);
- Additional pressure from tourism demand;
- Continuous urban development. Southern Colorada gained around 690,000 residents between 2002 and 2018.
- Drinking water shortages. The U.S. Bureau of Reclamation’s Colorado River produced projections of Lake Mead water levels. Based on this, the Secretary of the Interior can make a shortage declaration if it is forecasted below 1,075 feet on January 1 of the following year.
- Dependence on the Colorado River Basin, in a desert environment;
- Declining water quality. Resevoir volumes and rising stream flows can affect quality of water, which is sensitive to both anthropogenic and natural pressures (Hamid & al., 2019);
- Blooming of harmful algae in fresh water reservoirs under climate and environmental changes;
- Increased droughts. Since 2000, the Colorado River Basin has experienced decreasing snowfalls and runoffs from surronding mountains that resulted into the “worst drought in the Basin’s recorded history” in 2018. “As of late 2019, the combined water storage in the Colorado River’s two primary reservoirs (Lake Mead and Lake Powell) was at just 47 percent of capacity” (SNWA Water Resource Plan 2019);
- Flash floods is a permanent risk that can occur all year long despite rising droughts, and with higher occurence during the monsoon season (July-September).
- Modernisation of energy-intensive municipal buildings and construction of new LEED-compliant facilities;
- Incentives to improve building efficiency in the face of high temperatures;
- Renewable energies and smart grids to guarantee and manage energy consumption during peak periods (summer cooling) on the hottest days.
- Awareness campaigns for residents and motorists to avoid flooded areas and reduce water consumption and watering;
- Development of the WET (Water Saving Technologies) programme for residential and commercial customers to help them reduce indoor water consumption.
SUPPLY AND DEMAND MANAGEMENT:
- Water use restrictions based on low supply times and days. Water conservation programs led by SNWA allowed to cut per capita consumption of water by 46% between 2002 and 2018;
- Construction of a third intake at Mead Lake. A new Low Lake Level Pumping Station at Lake Mead is due to 2020 to help Southern Colorado accessing Colorado River’s water supplies below 1,000 feets;
- Study of groundwater development and flow from eastern Nevada to Las Vegas (project under study for over a decade while groundwater rights have been acquired).
- Long-term flood control master plan through the construction of retention basins and flash flood mitigation infrastructure. The Clark County Regional Flood Control District (CCRFCD) is in charge of coordinating, implementing and funding the Master Plan;
- Emergency plans for flash floods and rescues by local public safety actors (fire, police and first responders);
- Establishment of flood zone mapping (insurance sector requirements).
- Specific green buildings to mitigate the urban heat island effect;
- Restriction of landscaping for new residential and commercial construction;
- Incentives to replace existing turf with low-water landscaping (cactus);
- Residential and commercial sheds to help reduce outdoor water consumption;
- Incentives to replace turf with synthetic (Cash for Grass programme);
- A programme to plant trees and green spaces in downtown Las Vegas;
- Zoning the Las Vegas Valley floodplain against urban development;
- Designation of national monuments, federal lands and protected spaces to restrict development;
- Integration of shade, green and ventilated spaces into the Las Vegas Downtown Masterplan.
- Integration of adaptation measures into the City’s 2050 Master Plan;
- Provision of air-conditioned commercial areas during hot days.
Strenghts of the approach
- The approach strengthens awareness and measures already in place for water resource saving;
- The 2018 SNWA Water Resource Plan and Water Budget presents many options at customer level;
- The approach also sheds light on local public decision-making on climate change adaptation.
Limits of the approach
- There is a lack of a participatory approach and integration of populations in the search for solutions. Institutional actors and institutions, especially Federal and State-level water agencies, took an overwhelming part in the process;
- In the options presented, engineering and technical solutions might prevail too much over an approach that would manage supply and demand of water through planning measures;
- There are only few options for radical transformations of the existing water distribution system, while it is highly water-intensive and draws a lot on available resources.
This case study is part of six territorial adaptation case studies of the ‘Adaptation Book’. The book tells the political and conceptual story of adaptation in international climate negotiations (section 1), before analyzing subnational and local governments initiatives (section 2) through global reports and case studies. We then study adaptation issues raised and answers provided in six sectors of the economy (section 3), to finally conclude with an overview of financial flows and tools for adaptation (section 4).
Climate Chance & Comité 21 (2019). “Adaptation Book” Synthesis Report 2019 on Adaptation Action. Global Observatory on Non-state Climate Action.
- CDP data (2019)
- US EPA (n.d.). Southern Nevada Water Authority Assesses Vulnerability To Climate Change
- Water Utility Climate Alliance (2018). Strategic Plan and Publications
- Southern Nevada Water Authority (2018). 2018 Water Resource Plan
- Division of Emergency Management – Homeland Security (2018). The State of Nevada Enhanced Hazard Mitigation Plan
- ArcGIS. Extreme Weather Adaptation in Las Vegas, Nevada
- Water Sector Climate Change Adaptation Guidance Note
- Using climate information for Climate-Resilient Water Management: Moving from science to action
- Nature Based Solutions for Water: The United Nations World Water Development Report 2018