Subsidence from Aquifer-Storage and Recovery in the East Bay Plain

Science Center Objects

The East Bay Municipal Utility District (EBMUD) has proposed to store and recover as much as 10 million gallons of water per day (MGD) at an aquifer storage and recovery (ASR) site, the Bayside Groundwater Project. Water will be stored in a 100-ft sequence of coarse-grained sediment (the "Deep Aquifer") underlying the East Bay Plain and the adjacent Niles Cone ground-water basin.

The Deep Aquifer is overlain by more than 500 ft of clayey fine-grained, sediments and likely underlain by comparable units. These sediments are similar to the clayey sediments found in the nearby Santa Clara Valley where inelastic compaction has resulted in 13 feet of subsidence. Thus, aquifer storage and recovery could cause subsidence around the southern East Bay Plain and might induce coastal flooding and reduce the ability of flood control channels to remove surface runoff from urbanized areas during storms. EBMUD needs to identify the potential for subsidence during ASR operations and develop subsidence monitoring tools that can be used to guide ASR operation.

The objective is to monitor, analyze and simulate aquifer-system compaction and expansion, and consequent land subsidence and ground inflation resulting from natural causes and any anthropogenic causes related to ground-water development and ASR activities at EBMUD's Bayside Groundwater Project.