# Data-Collection Stations Reports

Version 3 and beta version 4 both have single national user interfaces through which information can be obtained for data-collection stations anywhere in the United States. Information for stations within a state where StreamStats has been implemented can be obtained using the version 3 application for that state. Individual state applications may be accessed through the Version 3 State Applications link. The Beta Version 4 Application may be used to obtain information for streamgages in states that are not implemented in version 3. Links to these applications appear in the gray box to the left on this page, and on most other StreamStats web pages.

Station information can be obtained using version 3 by (1) zooming in to the area in which a station of interest is located, (2) clicking on the *Streamgage Information* button , and then (3) clicking on the triangular map symbol that indicates the station location. Station information can be obtained using beta version 4 by (1) either typing the streamgage number or name into location search box near the top of the sidebar or zooming in to the area in which the station of interest is located, (2) clicking on the *Exploration Tools* button , and then (3) clicking on the *Query Streamgages* button .

The output appears in a pop-up Web browser window. At the top of the window is the USGS logo, followed by the title, "StreamStats Data-Collection Station Report.” Immediately below the title, the official USGS station number, the station name, and a hyperlink to the NWIS-Web site for the station are provided. NWIS-Web is a USGS national database from which users can obtain period-of-record streamflow data time series and real-time information, if available, for the stations. For stations in North Carolina only, links appear below the NWIS link to two text files of additional streamflow statistics. Below this, four tables are provided. The information that is available in the tables varies substantially among stations according to the data that have been collected there, and the analyses that have been done by the local USGS office on those data.

## Descriptive Information Tables:

Information provided in this table may include:

Station type: Indicates the type of record collected at the station. Possible types are: continuous-record streamgage, low-flow partial-record station, peak-flow partial-record station, peak- and low-flow partial-record station, miscellaneous-measurement station, peak-flow partial record and stage-only, continuous-record stage-only, and undefined.

Location: Describes the location of the station.

Gage: Describes the installed instrumentation and the gage datum.

Regulation and Diversions: Describes any human manipulation of streamflow at the station.

Regulated?: Indicates if streamflow at the station is affected by flow regulations or diversions. Possible values are True, False, or Unknown

Period of Record: Indicates the starting and ending years of data collection

Remarks: Provides description of any factors that affect the flow conditions at the station.

Latitude: Latitude of the station location, in decimal degrees, NAD83

Longitude: Longitude of the station location, in decimal degrees, NAD83

Hydrologic unit code: The 8-digit hydrologic cataloging-unit number assigned to the drainage basin in which the station is located. Additional information can be obtained at http://water.usgs.gov/nawqa/sparrow/wrr97/geograp/geograp.html

County: The name of the county in which the station is located

## Physical Characteristics Tables:

These tables may contain any of potentially hundreds of physical characteristics of the drainage basin that contributes streamflow to a data-collection station. The table is separated into sections of characteristics of the same type. The types may include precipitation, temperature, climate, runoff, flood depth, recharge, topographical, soil, geological, stream channel, basin dimensional, and burned area characteristics, as well as additional descriptive information. The table consists of four columns:

- Characteristic Name - gives the names of the characteristics
- Value - gives the quantity of the characteristic that was measured for the station
- Units - gives the English units of measure for the value
- Citation Number - gives a number that corresponds with the Citation Number in the Citations table. Each physical characteristic and streamflow statistic that is provided by StreamStats has been published previously in a report that is cited in the Citations table and is referenced by the Citation Number in the other tables.

Definitions for the basin characteristics are provided on the Basin Characteristics Definitions page.

## Streamflow Statistics Tables:

These tables may contain any of more than 1,400 streamflow statistics separated into as many as 26 sections of statistics of the same type, such as peak-flow statistics, low-flow statistics, and flow-duration statistics. The tables include up to 13 columns:

- Statistic Name - gives the names of the statistics. Within the table, the statistics are grouped by statistic type.
- Value - gives the computed value for the corresponding statistic
- Units - gives the English units of measure for the value
- Citation Number - gives a number that corresponds with the Citation Number in the Citations table
- Preferred? – indicates Y if the statistic is the preferred value, and N if it is not preferred
- Years of Record – the number of years of record that were used to compute the statistic
- Standard Error, percent – the standard error, in percent, of the computed statistic, which indicates there is an approximately 2/3 chance that the true value is within the given percentage of the provided value
- Variance, log-10 – the variance of the estimate, as computed from the base-10 logarithms of the data that were used to compute the statistic
- Lower 95% Confidence Interval – the lower end of the interval within which there is a 95 percent chance that the true value of the statistic occurs
- Upper 95% Confidence Interval – the upper end of the interval within which there is a 95 percent chance that the true value of the statistic occurs
- Start Date –the beginning date of the period of record that was used to compute the statistic
- End Date - the ending date of the period of record that was used to compute the statistic
- Remarks – optional comments about how the statistic was computed

Typically, when a new value of a statistic is published for a station, and the new value was computed using a longer record or improved methods, or both, then the new value is considered to supersede the older value. As a result, normally when new values of a statistic become available they replace the older values in the database that stores the statistics for StreamStats. However, StreamStats can provide multiple values of the same statistic in cases where there is justification to do so. An example is where a state has regulations that require the use of statistics from a specific report, but newer values have become available since the report was published. In such cases, IsPreferred? will be set to Y for the newer value and to N for the older value, and both values will appear in the statistics table.

Unless otherwise noted, all streamflow statistics presented in the output tables, except low-flow frequency statistics, were computed on the basis of water years, which begin October 1 of the preceding year and end September 30 of the given year. Low-flow frequency statistics, such as the 7-day, 10-year low flow, were computed on the basis of climatic years, which begin on April 1 of the given year and end on March 31 of the following year. Statistics that were computed using data from nonstandard time periods or periods of less than a year will indicate those time periods in their names and definitions.

Definitions for the streamflow statistics are provided on the Streamflow Statistics Definitions page.

## Citations Tables:

These tables contain columns of the citation numbers given in the previous tables, the corresponding citations for the reports that contain the statistics, and links to the online versions of the reports, respectively. Users can refer to those reports to determine when, why, and how the statistics were calculated.

Many of the statistics presented in the tables have an associated citation of “Imported from Basin Characteristics file.” The Basin Characteristics File (BCF) was a USGS database that was retired in the late 1990s. No time tags were associated with any of the data entered in the BCF. As a result, users should understand that information from the BCF is likely to be 20 or more years old. In many cases, newer information is available in reports published by the various USGS Water Science Centers. Users should check the Web pages of the individual Centers to determine if reports containing newer statistics are available.