From California Agriculture:
“Sustaining the remarkable scale of agriculture in the San Joaquin Valley has required large imports of surface water and an average annual groundwater overdraft of 2 million acre-feet (Hanak et al. 2017). This level of water demand is unsustainable and is now forcing changes that will have profound social and economic consequences for San Joaquin Valley farmers and communities. Land will have to come out of agricultural production in some areas. Yet, the emerging changes also provide an important opportunity to strike a new balance between a vibrant agricultural economy and maintenance of natural ecosystems that provide a host of public benefits — if the land is retired and restored strategically.
Once characterized by widespread artesian wells, the San Joaquin Valley now averages groundwater depths of over 150 feet below the surface, exceeding 250 feet in many areas. Decades of groundwater withdrawals have led to the declining reliability and quality of groundwater (Hanak et al. 2015; Harter et al. 2012), widespread land subsidence exceeding 25 feet in some areas (CADWR 2014; Farr et al. 2017) and degradation of groundwater-dependent ecosystems (The Nature Conservancy 2014). … “
Continue reading from California Agriculture here: Groundwater sustainability in the San Joaquin Valley: Multiple benefits if agricultural lands are retired and restored strategically