User’s Guide for the New York Streamflow 

Estimation Tool (NYSET) version 1.0

By Christopher L. Gazoorian

Prepared in cooperation with The Nature Conservancy and the New York State 

Energy Research and Development Authority

Appendix 5 to accompany

Scientific Investigations Report 2014–5220 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2014

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Suggested citation:

Gazoorian, C.L., 2015, Estimation of unaltered daily mean streamflow at ungaged streams of New York, excluding Long Island, water years 1961–2010: U.S. Geological Survey Scientific Investigations Report 2014–5220, 10 p., 

http://dx.doi.org/10.3133/sir20145220.

ISSN 2328-0328 (online) 
iii

Contents

Introduction.....................................................................................................................................................1

Computer Requirements and Installation Instructions............................................................................1

Data Input Requirements..............................................................................................................................1

Running NYSET...............................................................................................................................................4

Evaluating Monthly Flows.............................................................................................................................4

Selected References...................................................................................................................................10

Figures

5–1. Screen capture of the Basin Characteristics screen of the New York Streamflow

Estimation Tool ..............................................................................................................................2

5–2. Screen capture of opening StreamStats screen of the New York Streamflow

Estimation Tool ..............................................................................................................................3

5–3. Screen capture showing an example entry of basin characteristics into the New

York Streamflow Estimation Tool. Black oval shows button to import data from

StreamStats; red oval shows basin characteristic warning; black arrow points to

the button to compute unaltered daily mean streamflows....................................................5

5–4. Screen capture of the summary report generated from the New York Streamflow

Estimation Tool. Black oval shows the button to export daily streamflow for the

ungaged location as a comma separated values (.csv) file..................................................6

5–5. Screen capture showing MonthlyFlows evaluation tool .......................................................7

5–6. Screen capture showing monthly exceedance probability flows as output from the

New York Streamflow Estimation Tool ......................................................................................8

5–7. Screen capture showing manual reference streamgage selection checkbox (black

oval) for use with the New York Streamflow Estimation Tool................................................9
iv
User’s Guide for the New York Streamflow Estimation Tool

By Christopher L. Gazoorian

Introduction

The New York Streamflow Estimation Tool (NYSET) 

is a tool to simulate minimally altered streamflow at a daily 

time step for an ungaged site for the time period from October 

1, 1960, to September 30, 2010. NYSET was developed by 

the U.S. Geological Survey in cooperation with The Nature 

Conservancy and the New York State Energy Research and 

Development Authority. The tool uses a modified QPPQ 

approach (Fennessey, 1994; Archfield and others, 2010), 

which relates probability exceedences at a gaged site, termed 

a reference streamgage, to an ungaged site. An appropriate 

reference streamgage is selected by the NYSET using 

streamflow correlation, or the user can manually select a 

different reference streamgage. A report file is generated 

documenting a summary of the reference streamgage and 

ungaged site information, any warnings, and basic statistics 

including the mean and median daily flows for WYs 1961 

to 2010, and rank-based 7-day, 2-year (7Q2), 7-day, 10-year 

(7Q10), and select monthly exceedances. The estimated daily 

flows for the ungaged site can be easily exported to a comma 

separated values (.csv) file that can be used as input into a 

statistical software package to determine further streamflow 

statistics. More information related to the methodology used 

in the development of NYSET can be found in the body of 

this report.

Computer Requirements and 

Installation Instructions

Microsoft® Windows® 7 or 8, Microsoft® Excel 1997 

or 2010 (or later), and Visual Basic .NET framework 4.5.1 

are required on the machine running NYSET.1The tool and 

associated report can be downloaded from the U.S. Geological 

Survey (USGS) Publications Warehouse. To download the 

NYSET, go to http://pubs.usgs.gov/sir/2014/5220/, click on 

the “NYSET” link, and download NYSET_v.1.0.zip. Extract 

the files from the zip file and save them to your computer. 

Install NYSET by double clicking on the file “setup.exe” 

1

 Microsoft®, Windows® and Excel are either registered trademarks or trademarks of Microsoft® Corporation in the United States and/or other countries.

(administrative privileges are not typically required to install 

or uninstall this application). During this step, the program 

checks for prerequisites and will notify you of any problems 

or missing software. After successful installation, the program 

will be found in your start menu in a folder named “USGS NY 

WSC”; a shortcut will also be created on your desktop.

Data Input Requirements

NYSET requires basin characteristics for the ungaged 

site to be entered on the “Basin Characteristics” tab (fig. 5–1). 

The opening screen of NYSET is an interface with the USGS 

StreamStats for New York Web page for New York (fig. 5–2). 

From the opening screen, users can select an ungaged stream 

location, delineate a watershed boundary and obtain the 

required basin characteristics. This can also be done outside 

of the NYSET with StreamStats. An Esri file geodatabase 

(.gdb) that includes a shapefile of the watershed area and basin 

characteristics can be downloaded from StreamStats. Basin 

characteristics can also be entered manually in the “Basin 

Characteristics” tab. The following basin characteristics 

need to be entered: drainage area, mean annual runoff, 

percent hydrologic soils group A, percent hydrologic soils 

group B, mean monthly precipitation for the months of May, 

June and July, mean summer precipitation, maximum June 

temperature, X location of the basin centroid, Y location of 

the basin centroid, X location of the basin outlet, Y location 

of the basin outlet, slope of the lower one-half of the main 

channel and the percent of basin above 1,200 feet of elevation. 

More information about these basin characteristics, including 

data sources, can be found in the body of this report. It is 

important to use the same data source as was used to develop 

the regression equations for determination of the basin 

characteristics to maintain consistency in the accuracy of the 

regression estimates. This is not possible for some areas where 

SSURGO (U.S. Department of Agriculture, Natural Resources 

Conservation Service, 2011) data were unavailable; Digital 

General Soil Map of the United States (STATSGO2; U.S. 

Department of Agriculture, Natural Resources Conservation 

Service, 2013) data have been included in StreamStats to 

complete areas where SSURGO data are missing. Accuracy 

may vary from what was found in the regression analysis. 
2 User’s Guide for the New York Streamflow Estimation Tool

Figure 5–1. Screen capture of the Basin Characteristics screen of the New York Streamflow Estimation Tool
Data Input Requirements 3

Figure 5–2. Screen capture of opening StreamStats screen of the New York Streamflow Estimation Tool.
4 User’s Guide for the New York Streamflow Estimation Tool

To clear entered basin characteristics, click on the button 

“Clear Form.” This will also clear any computed statistics 

and reference streamgage information summarized on the 

graphical user interface from an earlier analysis.

Running NYSET

The opening screen of NYSET is an interface with 

USGS StreamStats for New York. The user can navigate to 

and download the data for the desired stream basin using 

the StreamStats tools. When the user selects a basin in 

StreamStats, the latitude and longitude of the pour point are 

imported into the NYSET “Basin Characteristics” tab. After 

the ungaged basin delineation is complete, the user will be 

prompted to proceed with importing the basin characteristics 

into NYSET. If declined, the user can import the statistics 

later by clicking the “Import basin characteristics” button on 

the “Basin Characteristics” tab (fig. 5–3, black circle). If the 

location coordinates are not filled out, NYSET will not import 

any basin characteristics. The “Basin Characteristics” tab 

includes cells to enter basin characteristics manually if they 

are known. The range of values for each basin characteristic 

used to develop the regression equations is shown. A warning 

message will appear if the basin characteristic entered is 

outside this range (fig. 5–3, red circle), indicating the resulting 

flow-duration estimates determined from regression equations 

may not be valid.

After basin characteristics have been entered for the 

ungaged location, the user can choose whether to allow 

NYSET to select the reference streamgage to be used or 

select a different one. If the user would like to select the 

reference streamgage, uncheck the box “Let the NYSET 

choose” under the “Reference Gage Selection” tab. Next, click 

on the “Compute Unaltered Streamflows” button (fig. 5–3, 

arrow) to compute baseline daily flows. The user will have to 

agree to the disclaimer that appears before continuing. The 

computation of daily flows will take a few minutes, depending 

on the processing capacity of your computer. A status bar 

indicates progress. When computations are completed, a box 

will open asking you to save the resulting Microsoft® Excel 

output file. After saving the file, close or save the file under 

a new name before attempting to run NYSET again. NYSET 

may not function properly when the previous output file 

is open.

The Microsoft® Excel summary output files contain 

worksheets with reference gage information, daily flows 

for the reference site and ungaged location, probability 

exceedances for the reference site and ungaged location, a 

summary report with hydrographs and flow-duration curves 

(fig. 5–4), and a tool to manipulate additional monthly 

withdrawals and discharges (fig. 5–5). An additional 

spreadsheet displaying select monthly exceedance probability 

flows is also created and can be saved to a user defined 

directory (fig. 5–6). The worksheet named “Reference Gage 

Selection” lists information about the reference streamgage 

selected and five reference streamgages with the highest 

correlations to the ungaged location. The distances between 

the ungaged location and reference streamgages are listed in 

the table and can be used to evaluate the appropriateness of 

the selected streamgage. To save the estimated daily flows and 

dates for the ungaged location as a .csv, click on the “Export 

Daily Values” button on the report worksheet (fig. 5–4, black 

circle). Macros need to be enabled in Microsoft® Excel to use 

this feature. To enable macros, click directly on the “Enable 

Content” button on the yellow security message bar (if it 

appears) or from File, Options, Trust Center, Trust Center 

Settings and select the required options.. The exported .csv file 

can then be used as input into a number of statistical software 

packages to determine low-flow, flow-duration exceedance, 

base flow, or mean-flow statistics.

The reference streamgage can be chosen by the user, 

overriding the spatial map correlation process. After the basin 

characteristics have been entered for the ungaged location in 

NYSET, go to the “Reference Gage Selection” tab (fig. 5–7, 

black circle), and choose the reference streamgage you want 

to use. Click on “Compute Unaltered Streamflows” to proceed 

with calculations. Review the results and follow the data 

export procedures to save the data to a file for further use.

Evaluating Monthly Flows

Using the “MonthlyFlows” tab on the output summary 

file, the user can manipulate additional monthly withdrawals 

and discharges, designate monthly instream-flow targets 

and determine the remaining instream-flow after the user 

defined alterations (fig. 5–7). The “Unaltered streamflow” 

column is automatically filled in with the mean monthly 

flows for each month. This can be changed to any of the 

exceedence flows provided on the right side of the table or 

from the “MonthlyStats” tab in the monthly exceedance 

worksheet (fig. 5–7), depending on the user’s preference. The 

“Instream-flow target” column can be filled in by the user 

to represent the minimum desirable flows. By entering the 

instream-flow target, the user will see the “Difference from 

target” values change. The “Difference from target” column 

represents the surplus or deficit from the instream-flow target 

designated by the user for the exceedance or mean flows used 

in the “Unaltered streamflow” column. For example, if the 

Q50 (50-percent exceedance flow) flow in January is 100 

cubic feet per second (ft3/s; “Unaltered streamflow”) and the 

instream-flow target was 80 ft3/s, then there would be a surplus 

(“Difference from target”) of 20 ft3/s, 50 percent of the time. 
Running NYSET 5

Figure 5–3. Screen capture showing an example entry of basin characteristics into the New York Streamflow Estimation Tool. Black 

oval shows button to import data from StreamStats; red oval shows basin characteristic warning; black arrow points to the button to 

compute unaltered daily mean streamflows.
6 User’s Guide for the New York Streamflow Estimation Tool

Figure 5–4. Screen capture of the summary report generated from the New York Streamflow Estimation Tool. Black oval shows the 

button to export daily streamflow for the ungaged location as a comma separated values (.csv) file.
Running NYSET 7

Figure 5–5. Screen capture showing MonthlyFlows evaluation tool.
8 User’s Guide for the New York Streamflow Estimation Tool

Figure 5–6. Screen capture showing monthly exceedance probability flows as output from the New York Streamflow Estimation Tool.
Running NYSET 9

Figure 5–7. Screen capture showing manual reference streamgage selection checkbox (black oval) for use with the New York 

Streamflow Estimation Tool.
10 User’s Guide for the New York Streamflow Estimation Tool

If additional withdrawals were specified, then the “Difference 

from target” value would be reduced by those withdrawals.

Selected References

Archfield, S.A., Vogel, R.M., Steeves, P.A., Brandt, S.L., 

Weiskel, P.K., and Garabedian, S.P., 2010, The Massachusetts sustainable-yield estimator—A decision-support tool 

to assess water availability at ungaged stream locations in 

Massachusetts: U.S. Geological Survey Scientific Investigations Report 2009–5227, 41 p., plus CD–ROM. [Also available at http://pubs.usgs.gov/sir/2009/5227/.]

Fennessey, N.M., 1994, A hydro-climatological model of daily 

streamflow for the northeast United States: Medford, Mass., 

Tufts University, Ph.D. dissertation, [variously paged].

Ries, K.G., III, Guthrie, J.G., Rea, A.H., Steeves, P.A., and 

Stewart, D.W., 2008, StreamStats—A water resources web 

application: U.S. Geological Survey Fact Sheet 2008–3067, 

6 p. [Also available at http://pubs.usgs.gov/fs/2008/3067/.]

Stuckey, M.H., Koerkle, E.H., and Ulrich, J.E., 2012, Estimation of baseline daily mean streamflows for ungaged 

locations on Pennsylvania streams, water years 1960–2008: 

U.S. Geological Survey Scientific Investigations Report 

2012–5142, 61 p. [Also available at http://pubs.usgs.gov/

sir/2012/5142/.]