Professional Presentations:

Setback Levees in Exhausted Peat Areas; Hultgren, Edwin M. and Rachel Martin; CALFED Bay-Delta Program Science Conference, Sacramento, California; October 2008

Setback levees may be used to create more robust levees, to protect high-value or critical structures, and/or to create enhanced flood plains.  This presentation described the practical aspects of constructing a setback levee in those large portions of the Sacramento – San Joaquin Delta where the peat is exhausted or nearly so in the fields.  Yet peat remains buried within the existing levee core.  A small (1,000-feet-long) setback levee was constructed in the South Delta in 2008.  This presentation describes the approach used to develop and restore as Fill material sources were developed from local (on-island) borrow areas, which will be restored to agriculture following completion of the project.  Levee sections were designed using the available local materials. Construction sequences were developed to maintain flood protection and foundation stability.  Levels of effort in terms of man-power and equipment to construct the levee and cost estimates of levee construction were presented.