U.S. Department of the Interior

U.S. Geological Survey Printed on recycled paper

Fact Sheet 2018–3003

January 2018

Prepared in cooperation with the Missouri Department of Natural Resources

Missouri StreamStats—A Water-Resources Web Application

Missouri StreamStats (https://streamstats.usgs.gov), a geographic information system-based web application, is a tool 

for calculating basin characteristics and selected streamflow statistics for user-selected sites on streams in Missouri.

National Hydrography Dataset (NHD)

National Elevation Dataset (NED)

Watershed Boundary Dataset (WBDS)

Figure 1. Missouri StreamStats underlying datasets.

Introduction

The U.S. Geological Survey (USGS) maintains and operates more than 8,200 continuous streamgages nationwide. 

Types of data that may be collected, computed, and stored for 

streamgages include streamgage height (water-surface elevation), streamflow, and water quality. The streamflow data allow 

scientists and engineers to calculate streamflow statistics, such as 

the 1-percent annual exceedance probability flood (also known 

as the 100-year flood), the mean flow, and the 7-day, 10-year 

low flow, which are used by managers to make informed water 

resource management decisions, at each streamgage location. 

Researchers, regulators, and managers also commonly need 

physical characteristics (basin characteristics) that describe 

the unique properties of a basin. Common uses for streamflow 

statistics and basin characteristics include hydraulic design, watersupply management, water-use appropriations, and flood-plain 

mapping for establishing flood-insurance rates and land-use zones. 

The USGS periodically publishes reports that update the values 

of basin characteristics and streamflow statistics at selected gaged 

locations (locations with streamgages), but these studies usually 

only update a subset of streamgages, making data retrieval difficult. Additionally, streamflow statistics and basin characteristics 

are most often needed at ungaged locations (locations without 

streamgages) for which published streamflow statistics and basin 

characteristics do not exist. Although the USGS publishes manual 

methods for the estimation of streamflow statistics at ungaged 

locations, the calculations can be complex, often requiring specialized computer software and interpretation that can lead to inconsistent results.
Missouri StreamStats is a web-based geographic information system (GIS) that was created by the USGS in cooperation 

with the Missouri Department of Natural Resources to provide 

users with access to an assortment of tools that are useful for 

water-resources planning and management. StreamStats allows 

users to easily obtain the most recent published streamflow 

statistics and basin characteristics for streamgage locations 

and to automatically calculate selected basin characteristics 

and estimate streamflow statistics at ungaged locations. Missouri StreamStats is constructed based on the integration of the 

National Hydrography Dataset (1:24,000 scale), the Watershed 

Boundary Dataset (1:24,000 scale), and the 10-meter resolution 

digital elevation data from the National Elevation Dataset (NED) 

(fig. 1).

The current (2018) application supports the following features:

•	 View and navigate a base-map interface that 

features roads, streams, political boundaries, and hydrologic boundaries (fig. 2);

•	 Zoom in or out to different map scales using 

(1) a drawn rectangle around an area of 

interest, (2) latitude and longitude coordinates, or (3) a specified scale;

•	 Access previously published streamflow 

statistics, basin characteristics, and descriptive information for each current and 

discontinued streamgage (fig. 3);

•	 Link streamgage locations (fig. 4) to the 

National Water Information System where 

users can access historical and real-time 

data;

•	 Delineate a basin from a user-selected location and edit the basin boundary, if necessary (fig. 5);

•	 Download delineated basins as a GIS 

feature class with basin characteristics and 

streamflow statistics saved as attributes;

•	 Determine selected basin characteristics 

including drainage area, longest flow path, 

main-channel slope, basin shape, impervious area, and composite curve number for 

any delineated basin;

•	 Modify the basin characteristics that are 

used as explanatory variables in regression equations for estimating streamflow at 

ungaged locations;

•	 Estimate values of selected streamflow 

statistics including low flows, rural flood 

frequency, and urban flood frequency;

•	 Obtain plots of land surface and stream 

elevation profiles between two user-selected 

points;

•	 Measure distance between two user-defined 

points on the land surface or on the stream 

network; and

•	 Print the results in the map frame.

StreamStats

Figure 2. StreamStats user interface.

Figure 3. StreamStats data collection station report.
Figure 4. An example of a streamgage data collection location (Photograph of Fall 

Hollow tributary, Ft. Leonard Wood, Missouri, Larry Buschmann, U.S. Geological 

Survey, 2013).

Figure 5. A basin delineated at an ungaged location.

User Interface

StreamStats consists of

•	 a user interface that displays 

base maps and the 24K NHD 

network on which users can 

select a point of interest;

•	 a database (StreamStatsDB) 

that contains previously published streamflow statistics, 

basin characteristics, and 

descriptive information for 

USGS streamgages;

•	 a GIS process that automatically delineates basin 

boundaries and determines 

basin characteristics for 

user-selected ungaged locations on the stream network 

(fig. 6);

•	 a geographic database (geodatabase) that stores basemap data; and

•	 an automated process that 

uses determined basin 

characteristics to estimate 

selected streamflow statistics 

at ungaged locations using 

regression equations.
Parameter 

Code Parameter Description Value Unit

BSHAPE Basin Shape Factor for Area 9.36 dimensionless

CSL10_85 Change in elevation divided by length between points 10 

and 85 percent of distance along main channel to basin 

divide - main channel method not known 

3.64 feet per mi

DRNAREA Area that drains to a point on a stream 1320 square miles

IMPNLCD01 Percentage of impervious area determined from NLCD

2001 impervious dataset 

0.57 percent

LFPLENGTH Length of longest flow path 111 miles

STREAM_VARG Streamflow variability index as defined in WRIR 02-4068, 

computed from regional grid 

0.47 dimensionless

Basin Characteristics

Figure 6. Example of basin characteristics determined at an ungaged location.

The StreamStats interface allows users to select a location 

of interest on the stream network. If a streamgage location is 

selected, StreamStats will provide published streamflow statistics and basin characteristics for that site from the StreamStatsDB and give the user a link to the National Water Information System website to view real-time and historical data at 

active streamgage locations. If an ungaged location is selected, 

StreamStats automatically delineates the basin upstream from 

the selected location and prompts the user for confirmation that 

the delineation is correct. StreamStats then provides a selection 

of streamflow statistics to estimate and determine the basin characteristics required to compute the desired streamflow statistics 

and provides an option to download a GIS feature class of the 

drainage basin boundary that can be imported into a local GIS. 

A summary report of the determined basin characteristics and 

estimates of streamflow statistics is provided to the user.

Streamflow Statistics at Ungaged Locations

Missouri StreamStats can be used to quickly and reproducibly estimate streamflow statistics at ungaged locations (fig. 7). 

The USGS has developed regional regression equations to estimate selected streamflow statistics at ungaged locations based on 

statistically significant basin characteristics at gaged locations. 

StreamStats uses GIS processes to determine the significant 

basin characteristics at ungaged locations, which are then used 

as explanatory variables in regional regression equations that 

estimate streamflow statistics at those locations.

Users of Missouri StreamStats should be familiar with 

the application and limitations of regional regression equations 

before calculating streamflow statistics. Links to the supporting 

USGS reports that describe these regional regression equations 

are provided in the references at the end of this document. The 

following statistics can be determined using the regional regression equations for Missouri:

•	 Low flows (1-day, 10-year; 2-day, 10-year; 3-day, 

10-year; 7-day, 10-year; 10-day, 10-year; and 60-day, 

10-year recurrence intervals);

•	 Rural flood frequency (the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, 

and 0.2-percent annual exceedance probability, which 

can be defined as the 2-, 5-, 10-, 25-, 50-, 100-, 200-, 

and 500-year recurrence intervals); and

•	 Urban flood frequency (the 50-, 20-, 10-, 4-, 2-, 1-, and 

0.2-percent annual exceedance probability), which can 

be defined as the 2-, 5-, 10-, 25-, 50-, 100-, and 500-

year recurrence intervals.

Limitations

StreamStats provides estimates of streamflow values based 

on published reports that detail the assumptions and conditions 

for which the estimates are accurate. Although users should be 

familiar with the specific assumptions that are unique to each 

streamflow statistic, there are common limitations that apply to 

all statistics estimated by StreamStats.

Estimates of streamflow statistics at ungaged locations 

in StreamStats assume that natural flow conditions exist. If 

anthropogenic activities upstream of a selected site modify flow 

conditions in timing, quantity, or duration, the user should adjust 

streamflow statistics to account for those activities.

During the development of each regional regression 

equation, specific ranges of basin characteristics for which 

estimates of the streamflow statistic were valid were identified. 

When StreamStats is used to obtain streamflow statistics for 
Figure 7. Example of flow statistics estimated at an ungaged location.

[LowFlow Region 2 SIR 2013 5090]

Parameter

Code Parameter Name Value Units

Min 

Limit

Max 

Limit

DRNAREA Drainage Area 1320 square miles 0.21 7380

STREAM_VARG Streamflow Variability Index from 

Grid

0.47 dimensionless 0.273 0.926

Low-Flow Statistics Parameters

Low-Flow Statistics Flow Report [100 Percent LowFlow Region 2 SIR 2013 5090]

Statistic Value Unit

1 Day 10 Year Low Flow 94.6 ft^3/s

2 Day 10 Year Low Flow 99.9 ft^3/s

3 Day 10 Year Low Flow 100 ft^3/s

7 Day 10 Year Low Flow 104 ft^3/s

10 Day 10 Year Low Flow 107 ft^3/s

30 Day 10 Year Low Flow 120 ft^3/s

60 Day 10 Year Low Flow 142 ft^3/s

Low-Flow Statistics Citation

Southard, R.E., 2013, Computed statistics at streamgages, and methods for estimating low-flow 

frequency statistics and development of regional regression equations for estimating low-flow 

frequency statistics at ungaged locations in Missouri: U.S. Geological Survey Scientific 

Investigations Report 2013–5090, 28 p. 

Figure 7. Example of flow statistics estimated at an ungaged location.

locations that have basin characteristics outside the specified 

range, StreamStats will provide a warning that extrapolation 

has happened. Users should not assume that streamflow statistics are accurate when basin characteristics are estimated using 

extrapolation.

Missouri StreamStats only determines basin characteristics 

and estimates streamflow statistics inside the state of Missouri 

and excludes locations on the main stem of the Mississippi, Missouri, Chariton, Nodaway, and Osage Rivers because upstream 

parts of those rivers have geospatial data that are not included in 

Missouri StreamStats.

Future Functionality

The underlying GIS processes that run StreamStats use 

10-meter resolution elevation data to determine the direction of 

flow in the basin. In urbanized areas, subsurface storm water 

networks can change the catchment areas of the urban flow 

system so that they do not match topographic flow areas. Higher 

resolution datasets are necessary to accurately delineate these 

urbanized basins.

An Urban StreamStats project, which uses higher 3-meter 

resolution elevation data that are currently (2018) available in 

most urban areas in conjunction with detailed infrastructure 

features to improve the estimation of streamflow statistics in 

St. Louis County, Missouri, is in development by the USGS in 

cooperation with the Metropolitan St. Louis Sewer District.

Stream network navigation is an upcoming feature that will 

allow users to navigate upstream or downstream on the stream 

network to identify structures that affect water quality or quantity downstream. Structures indexed to the NHD will be easily 

identified to alert users of activities that may affect streamflow 

estimates downstream. Users will also be able to trace the stream 

network downstream from any point to determine the flow path 

that water or contaminants may take.

Missouri StreamStats also can determine many more basin 

characteristics than are currently available. Users interested in including additional basin characteristics of streamflow statistics should 

contact the USGS to discuss their needs. The current (2018) list of 

possible basin characteristics is available at https://streamstatsags.

cr.usgs.gov/ss_defs/basin_char_defs.aspx (U.S. Geological Survey, 

2017).
Selected References

Huizinga, R.J., 2014, An initial abstraction and constant loss 

model, and methods for estimating unit hydrographs, peak 

stream flows, and flood volumes for urban basins in Missouri: U.S. Geological Survey Scientific Investigations Report 

2014–5193, 59 p. [Also available at https://pubs.usgs.gov/

sir/2014/5193/pdf/sir2014-5193.pdf.]

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 https://pubs.er.usgs.gov/usgspubs/fs/

fs20083067/.]

Southard, R.E., 2010, Estimating the magnitude and frequency 

of floods in urban basins in Missouri: U.S. Geological Survey 

Scientific Investigations Report 2010–5073, 27 p. [Also available at https://pubs.usgs.gov/sir/2010/5073/.]

Southard, R.E., 2013, Computed statistics at streamgages, and 

methods for estimating low-flow frequency statistics and 

development of regional regression equations for estimating 

low-flow frequency statistics at ungaged locations in Missouri: U.S. Geological Survey Scientific Investigations Report 

2013–5090, 28 p. [Also available at https://pubs.usgs.gov/

sir/2013/5090/.]

Southard, R.E., and Veilleux, A.G., 2014, Methods for estimating 

annual exceedance-probability discharges and largest recorded 

floods for unregulated streams in rural Missouri: U.S. Geological Survey Scientific Investigations Report 2014–5165, 39 p. 

[Also available at https://pubs.usgs.gov/sir/2014/5165/.]

U.S. Geological Survey, 2017, Basin characteristic definitions: 

U.S. Geological Survey StreamStats web page: accessed 

October 2017 at https://streamstatsags.cr.usgs.gov/ss_defs/

basin_char_defs.aspx.

For further information, please contact 

Director, Central Midwest Water Science Center

U.S. Geological Survey

1400 Independence Road

Rolla, MO 65401

(573) 308-3667

https://mo.water.usgs.gov/

Visit the USGS Office of Surface Water StreamStats 

Program homepage at https://water.usgs.gov/osw/

streamstats/.

The use of trade, product, or firm names in this report is for 

descriptive purposes only and does not imply endorsement by 

the U.S. Government.

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

https://doi.org/10.3133/fs20183003