Development of Streamflow Record Extension Equations in New Hampshire

Science Center Objects

Currently, there are 16 designated rivers in New Hampshire in need of daily mean streamflow estimates for managing instream flows. Many of New Hampshire’s Designated Rivers have current and/or historical streamflow data that may be used to extend an existing streamgages streamflow record in time through record extension techniques. Evaluating the feasibility of record extension techniques to provide the streamflow data necessary to manage New Hampshire’s designated rivers would provide valuable insight for optimizing the development of a cost-effective streamgaging network.

This investigation will evaluate record extension techniques at six previously gaged locations on designated rivers by relating previously published field measurements of discharge at discontinued stations to daily discharges at some nearby active streamgage.


  • Record extension techniques equations for estimates of daily mean streamflow for six discontinued streamgages. This would include upper and lower confidence intervals for daily mean streamflow.
  • Assessment of error in the extended streamflow record developed for the six previously gaged locations on designated rivers.