Keeping Water in Climate-Changed Headwaters Longer

February 2, 2024

Figure 1. A parched landscape at Tuolumne Meadows, Yosemite National Park, captured in October 2011 highlights a growing concern for the Park Service: the recent dryness, a troubling trend over the past two decades, affecting mountain meadows across the West. Credit: Mike Dettinger.

In the recent essay “Keeping Water in Climate-Changed Headwaters Longer” published in the San Francisco Estuary and Watershed Science journal, CW3E authors Michael Dettinger, Anna Wilson, and Garrett McGurk delve into strategies for improving water retention in California’s headwaters affected by climate change. The article recommends more proactive measures in headwater regions to address the adverse impacts of climate change on water resources, to augment current downstream-focused adaptation strategies. This research contributes to the Monitoring and Projections of Climate Variability and Change Priority Area in CW3E’S 2019-2024 Strategic Plan, by discussing water management decision-making in scenarios including current and future extremes.

The article emphasizes that current water management practices are not sufficient to tackle the root problems caused by climate change, such as warmer temperatures, increased evapotranspiration, more intense winter storms, flashier flows, and drier summer conditions. It proposes upstream interventions like beaver repopulation, forest health treatments, and Forecast Informed Reservoir Operations (FIRO) as means to delay water movement to downstream systems, better mimicking historical hydrographs, which could help mitigate winter flood risks, reduce summer dryness and wildfire dangers, and improve groundwater recharge.

The authors highlight that even minor efforts to prolong water retention in headwaters could significantly benefit downstream water supplies, potentially reducing the need for extensive, and more invasive, water management adaptations across California to cope with the impacts of climate change on water availability. For a detailed exploration of the challenges and ideas to spark work towards real and sustainable solutions, the full paper is available here.

Figure 2. View east from the Tahoe Rim Trail, captured in July 2019, showcases a dense yet vibrant forest of the sort being addressed by state-led treatments for wildfire prevention and forest health, with the rain-shadowed Pinon Range and expansive Great Basin stretching into the distance. Credit: Mike Dettinger.

Dettinger, M., Wilson, A., & McGurk, G. (2023). Keeping Water in Climate-Changed Headwaters Longer. San Francisco Estuary and Watershed Science, 21(4) https://doi.org/10.15447/sfews.2023v21iss4art1. Retrieved from https://escholarship.org/uc/item/7mq8174f