erc: who: United States. Environmental Protection Agency. what: Chapter 6: Management Measures for Hydromodification: Channelization and Channel Modification, Dams, and Streambank and Shoreline Erosion when: 19930100 where: https://digital.library.unt.edu/ark:/67531/metadc948721/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://digital.library.unt.edu/ark:/67531/