Due to growing recognition that climate change is having and will continue to have a substantial, measureable effect on California’s water resources, the California Department of Water Resources (DWR) created climate change adaptation strategies for the state's water supply. These strategies provide a new approach to managing California’s water supply and other natural resources in a way that is more resilient and robust to the effects of climate change.
Climate change is of growing concern to many natural resource managers; in California, the DWR is engaged in improving the state's ability to adapt to climate change impacts on water management. Aging infrastructure, population growth, and pollution infiltration, coupled with long droughts and impending climate change, threaten the water supply's reliability and quality.
Snowmelt from the Sierra Nevada mountain range currently provides an annual average of 15 million acre-feet of water. Historically, the snowpack melted between April and July each year and was captured by the state’s water infrastructure and subsequently stored for use during the drier summer and fall months. Over the past century, the spring snowpack in the Sierra Nevada range has decreased by 10 percent, causing a loss of 1.5 million acre-feet of snowpack storage (one acre-foot of snowpack is enough water for one to two families for one year). By 2050, climate models and the DWR project that the Sierra snowpack will be further reduced by 25 to 40 percent.
Climate change is also projected to cause more frequent and intense droughts and floods. Regions reliant upon surface waters could be acutely affected if runoff becomes more variable. Warmer temperatures could affect water demand; for example, water usage will likely increase to combat increased evapotranspiration rates in agriculture. If snowmelt timing is altered, the likelihood of intense flooding could increase if it coincides with times of heavy precipitation.
In 2008, the DWR released Managing an Uncertain Future, which outlined 10 adaptation strategies:
- Provide stable, long-term funding for statewide and integrated regional water management planning;
- Further develop and implement Integrated Regional Water Management (IRWM) planning, which offers a framework to address water-related challenges;
- Increase water use efficiency across the state and across sectors;
- Practice and encourage integrated flood management strategies;
- Protect and restore ecosystems;
- Expand the state’s water storage capacity for both surface water and groundwater, and encourage better management of groundwater resources;
- Work towards a thriving, sustainable Delta by addressing water supply, quality, and ecosystem condition issues;
- Increase monitoring efforts, data analysis, and management to reduce uncertainty;
- Incorporate sea level rise into management strategies; and
- Fund focused climate change and adaptation research and analysis to reduce uncertainty and facilitate planning for management activities.
To combat the effects of climate change on California’s water resources, the DWR is developing adaptation strategies in coordination with state, regional, and local interests. The DWR also recognizes that no single project or technique can adequately address all the issues California is facing, thus they are promoting the use of site-specific strategies. Helping water managers plan and invest early on will make the system more resilient to the variety of impacts climate change is expected to cause.
The DWR is promoting the IRWM approach through its IRWM Grant Program. The program provides funding to IRWM groups for developing plans and implementing projects identified in their plans. The IRWM Grant Program now requires IRWM groups to include climate change considerations in future plans. To assist the IRWM groups with incorporating climate change considerations, the DWR released the Climate Change Document Clearinghouse in June 2010. The document provides links to climate change-related reports with corresponding short synopses.
The DWR has also incorporated several climate change adaptation strategies, including IRWM, water conservation, and integrated flood management, as objectives in the 2009 California Water Plan. The California Water Plan, updated every five years, provides a framework for water managers, legislators, and the public to consider options and make decisions regarding California’s water future. The DWR’s climate change adaptation strategies are also included in the California Climate Adaptation Strategy. Led by the California Natural Resources Agency with participation from numerous state agencies, the California Climate Adaptation Strategy is a multi-sector strategy to help guide California’s efforts in adapting to climate change.
Feifel, K. (2010). California Department of Water Resources Adaptation Strategy [Case study on a project of the California Department of Water Resources]. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE: http://www.cakex.org/case-studies/california-department-water-resources… (Last updated November 2010)