The 2004 Failure of the Jones Tract Levee: Potential Causes and Repair Details

The June 3, 2004 failure of the Middle River levee protecting Upper Jones Tract in California’s Sacramento-San Joaquin Delta was unusual for several reasons. In the first place, the failure took place during late spring without either a flood or an earthquake. Secondly, while the levee is one of many in the Delta that holds back water every day from the adjoining below-sea-level farmland, it was considered one of the more robust levees in the Delta. Thus, its failure was unexpected and alarming. In the days and months that followed, local, state, and federal agencies worked to close the breach, keep the failure from cascading to other Delta islands, and to pump out the flood waters. In addition to farmland, critical water supply and highway infrastructure was at risk. This paper describes the flood-fighting efforts and emergency repair techniques used in the initial weeks to keep this event from becoming a regional emergency. It also describes the use of rockfill to close the breach as tidal water flowed in and out of the flooded island, and the subsequent need to add additional underwater fill to help seal the highly porous rockfill. In the end, over five separate construction contracts were involved in raising adjoining levees, providing slope protection to the interior slopes, closing the breach, pumping out the flood waters, and providing logistical support to flood fighters.
Litigation followed in the years after the levee failure and provided motivation for different groups to collect, compile, and review information that was previously unavailable in any one location. With this recently available compiled information, the potential causes of the failure are explored using data from cone penetration tests taken at the breach location following the failure together with recently available eyewitness accounts produced in depositions or court testimony. Piezometric data and the light unit weights of the organic soils present landward of the levee are also used to evaluate the potential for underseepage to be a cause of the failure and to compare the conditions at the failure site to another location where boils and uplift are currently occurring in a drainage ditch. Finally, the potential for animal burrowing to be a primary cause of the failure is discussed.