Over the past several years local Groundwater Sustainability Agencies (GSAs) charged with managing the region’s groundwater have been assessing the condition of the region’s groundwater resources and developing monitoring systems and management plans and projects to maintain the sustainability of these resources for the foreseeable future. These efforts have resulted in the completion of three Groundwater Sustainability Plans (GSPs) that cover each of the region’s groundwater subbasins – North American Subbasin, South American Subbasin, and Cosumnes Subbasin. The GSPs respond to State required planning criteria outlined in the 2014 Sustainable Groundwater Management Act (SGMA). The California Department of Water Resources webpage has information about SGMA, the GSP planning process, and a public portal containing the three GSPs for the Sacramento region.
ECOS, through the Water Committee, has participated in the development of these GSPs by attending public meetings and workshops, and providing comments on the draft plans. We have condensed these comments into a matrix comparing comments for each of the three GSPs. The matrix contains a summary of each original comment and, in bold, the actions taken by the GSAs to address each comment as documented in the final adopted GSPs. The full text of each ECOS comment letter can be found on the ECOS web site.
While some comments have been addressed in the final plans, others were not. For example, key aspects of the GSPs are six sustainability indicators that establish thresholds for when management actions must be taken to assure continued subbasin sustainability. The North American Subbasin GSP calls for management actions to be taken after one year of one or more of the GSP sustainability indicators exceeding action levels thus indicating the subbasin is in trouble. Unfortunately, the South American Subbasin allows three years of indicator exceedance that may lead to no actions being taken until the fourth year of an indicator being exceeded. The Cosumnes Subbasin did adjust their corresponding exceedance time periods but still allow a problem to exceed one or more threshold criteria for at least two years before actions to remedy the situation are taken. ECOS has argued that a one year exceedance criteria is acceptable and should be utilized in all three GSPs.
ECOS also believes climate change is not effectively addressed in the plans. All three GSPs base their management actions on a climate scenario that seems less realistic than current climate experience and the latest climate science indicates. This errant planning assumption may significantly overestimate the amount of groundwater available to meet demands in the future. If not corrected, sustainable management of the subbasins may be very difficult within the next decade.
ECOS members are meeting with the local GSA representatives to explore options to address our concerns prior to the next GSP updates which are due in 2025. Depending on the outcome of these meetings ECOS may find it necessary to participate in the State’s GSP public comment process.