New Mexico StreamStats

As of September 1, 2016, StreamStats was implemented for all of New Mexico in version 3. Previously, it had been implemented only for a pilot area in the northwestern part of the State. Basin delineations and computation of basin characteristics are available in version 4.This application implements regression equations for estimating bankfull statistics, the 4-day, 3-year low flow frequency, adjusted harmonic mean streamflow and instantaneous peak flows with probabilities of occurring in any given year of 50, 20, 10, 4, 2, 1, 0.5, and 0.2 percent. These peak-flow statistics also are referred to as the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year floods. The equations in New Mexico StreamStats, the methods used to develop them, and the limitations and errors associated with using them are documented in the report:

• Bell, M.T., and Tillery, A.C., 2023, Regression equations for estimating the 4-day, 3-year low-flow frequency and adjusted harmonic mean streamflow at ungaged sites for unregulated, perennial streams in New Mexico: U.S. Geological Survey Scientific Investigations Report 2023–5058, 31 p., https://doi.org/10.3133/sir20235058.
• Waltemeyer, S.D., 2008, Analysis of the magnitude and frequency of peak discharge and maximum observed peak discharge in New Mexico and surrounding areas: U.S. Geological Survey Scientific Investigations Report 2008–5119, 105 p.

In addition to presentation of the equations, the reports also describe the errors associated with the estimates obtained from the equations, the methods used to develop the equations, and the methods used to compute the basin characteristics included as explanatory variables in the equations. StreamStats users should familiarize themselves with the reports before attempting to obtain estimates of streamflow statistics for ungaged sites. Application of the peak-flow equations to ungaged sites assumes that flows at the sites occur under natural conditions. Application of the 4Q3 and adjusted harmonic mean equations to ungaged sites assumes perennial flow in addition to natural flow conditions. The equations in the above flood frequency report supersede previous equations that were published in 1985 and 2000 by the U.S. Geological Survey. The equations in the above low flow report supersede previous equations that were published in 2001 by the U.S. Geological Survey.

Click on this link to obtain general information on the New Mexico application, as well as specific sources and computation methods for basin characteristics.