Exceptional drought in California calls for innovative technology

The consequences of climate change hit differently in different parts of the world. Where some areas suffer from flood-risk due to storm-surges and more heavy rainfall, other regions, such as East and South Africa, and the Middle East suffer from severe periodic droughts. In the Western part of US, the climate swings back and forth with severe periodic droughts that can be followed by periodic, intense focused rainfall events called atmospheric rivers with associated flooding and other related damage, which appears to be the new normal due to climate change. In California, US, water year 2021 ended up as the second-driest year on record, followed in October by a category 5 atmospheric river, although current forecasts suggest that the sunny state is facing a potential third year of drought. The ongoing shrinkage of water stored behind the big dams in the major reservoirs is posing a growing risk to the water supply, so to avoid a crisis, Governor Gavin Newsom of California has issued an executive order asking residents to voluntarily reduce water usage by 15 percent compared with 2020. During a typical year, about 40 percent of the state’s total water supply comes from groundwater. During dry years, that amount increases up to 60 percent or more of the total supply and serves as a critical buffer against the impacts of drought and climate change. As the drought-prone state might be even more dependent on groundwater over the years to come, the authorities are currently increasing the focus on mapping and analyzing the groundwater resources, including identifying recharge areas to help replenish the aquifers when the water is available during the wet season and wetter years.

As an example, the California Department of Water Resources earlier this year selected a team of consultants led by Ramboll to conduct airborne electromagnetic surveys in California’s high- and medium-priority groundwater basins to provide data needed by local agencies developing and implementing groundwater sustainability plans. This project uses the SkyTEM technology developed in Denmark to conduct airborne electromagnetic (AEM) surveys in California’s high- and medium-priority groundwater basins. To further strengthen the knowledge sharing on water resources management between Denmark and California, the two states have signed Memorandums of Understanding (MoU) and increased collaboration between authorities, companies and universities. And in the beginning of December this year, a delegation led by the Danish Minister of Environment Lea Wermelin visited Folsom Lake to get a “real-life” understanding of how climate change is contributing to the California super drought. As an official part of the delegation Max Halkjær from Ramboll made a presentation about the AEM survey project and, more broadly, how innovative technology combined with the right knowhow and experience, can provide a decent contribution to the long-term sustainable management and replenishment of critically important groundwater resources.