The purpose of this report is to summarize the available hydrologic information for the Great Bay Estuary and Hampton-Seabrook Estuary. Estuary classification documents have been produced by Short (1992) and Jones (2000). UNH researchers have developed hydrologic models for the Great Bay Estuary (Brown and Arellano, 1980; Swift and Brown, 1983; Bilgili et al., 2005). Additional information has been created for licensing and regulatory reasons (e.g., PSNH, 1977). The information in these reports has been compiled and cross-checked against geographic databases and summarized in this report to provide accessible, consistent, and credible data. The values presented in this report will be used for all NHEP reporting and should be used for any national databases for estuarine classifications