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Welcome to StreamStats

New Hampshire

Beta version 4 has arrived!

Beta version 4 is now available for most states on a trial basis, and version 3 remains available. Beta version 4 provides a single user interface (at for all states that are implemented, rather than separate applications for each state, as in versions 2 and 3, and the user interface is more user friendly than previous versions. Information for user-selected ungaged sites currently cannot be obtained using beta version 4 for the States of Arkansas, Arizona, Georgia, Iowa, Indiana, Maryland, North Carolina, Oregon, South Carolina, and Tennessee because of unique functionality for those states that is not yet implemented. Users are encouraged to provide comments and report bugs by use of the Help button on the interface, which also provides access to limited beta version 4 documentation. See below for additional information about versions both 3 and 4.

Please contact the StreamStats by email at if you have any questions.

StreamStats for New Hampshire incorporates regression equations that can be used to estimate the long-term flood discharges at recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years. In addition, regression equations can provide estimates of the seasonal (spring, summer, fall, and winter) and annual 7-day 2-year (7Q2) and 7-day 10-year (7Q10) low-flow frequency values, as well as seasonal period-of record and period-of-record flow durations (60-, 70-, 80-, 90-, 95-, and 98-percent exceedences). The regression equations are applicable for ungaged reaches of unregulated New Hampshire streams. The reports below present the equations used to estimate the flow statistics, describe the errors associated with the estimates, and describe the methods used to develop the equations and to measure the basin characteristics used in the equations. Users should familiarize themselves with the reports before using StreamStats to obtain estimates of streamflow statistics for ungaged sites.


Interactive Map


General information on the Interactive Map application, as well as specific sources and computation methods for basin characteristics are available here.

StreamStats outputs report the uncertainty of the estimates for ungaged basins when basin characteristics for selected sites are within the ranges of the basin characteristics for streamgages that were used to develop the regression equations. Errors for basins with basin characteristics that are beyond these bounds are unknown. The applicable ranges of the basin characteristics are provided in the outputs and messages are provided when basin characteristics are outside of the applicable ranges.

The above report by Olsen (2009) describes a technique for estimating flood discharges at selected recurrence intervals for an ungaged site upstream or downstream from a streamgage using a drainage-area adjustment that is not implemented in StreamStats. Interested users should refer to the report for information on use of the method. StreamStats includes a different method for making such adjustments.

The basin characteristics and streamflow statistics presented for streamgages in the report by Flynn (2003) are not yet available through StreamStats. As a result, outputs obtained for ungaged sites when using the Estimate Flows Based on Similar Streamgaging Stations tool will not include estimates of streamflow statistics based on those presented by Flynn (2003).

StreamStats for New Hampshire was developed in cooperation with the New Hampshire Department of Transportation.

Link to New Hampshire Department of Transportation Link to New Hampshire Department of Environmental Services

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