PROJECT DESCRIPTION AND PURPOSE: This guidance document is an update and expansion of previous guidance on this topic first developed in 2005 (Version 1.0) and updated most recently in 2014 (Version 5.0). Rather than using the minimum criteria for wetland hydrology as a performance standard, performance standards specifying the optimum target hydrology for specific wetland plant communities have been refined for Version 6.0. This guidance is a living document and periodic updates will be made as needed. The purpose of this guidance is to ensure that consistent and enforceable hydrology performance standards, reflecting the best available science, are applied to compensatory mitigation proposals district-wide.