General Information

Project area general description

The State of New Jersey

Are any areas excluded?

Tidal areas and highly regulated stream reaches on the Rockaway, Wanaque, Hackensack, Pequannock, and Delaware Rivers have been excluded from basin delineation and statistics

Types of flow statistics available

Peak flows statewide, Baseline and recent (1989-2008) monthly low flow statistics

ArcGIS version used for processing

Originally 9.1, with some updates using 9.2 and 9.3, current version 10.1

Was TopoGrid used to process DEMs?


DEM and derivatives projection (general description)

North American Datum of 1983 (NAD 83)

DEM and derivatives (fdr, fac, etc.) resolution


DEM source

National Elevation Dataset;

Hydrography source

National Hydrography Dataset (1:24,000 NHD);

Hydrologic unit "walls" source

HUC-14 boundaries;

Gage basin boundaries source

not used

Interactive map snapping tolerance

2 cells


Basin Characteristics Methods and Sources



Computation method

Data Source


Variable label in report


Area that drains to a point on a stream in square miles.

polygon area


Watson and Schopp (2009)



Main-channel slope, in feet per mile. Difference in elevation (feet) between points 10-percent and 85-percent of the distance along main stream channel, from the gage or site of interest to the top of the basin, divided by distance (miles) between the two points.

custom, units feet/mile

10-meter DEM, 1:24,000 National Hydrograpgy Dataset (NHD)

Watson and Schopp (2009)



Percent of area covered by forest

percent of area

Percentage of area covered by forest cover, as interpreted from National Land Cover Dataset (NLCD) land-use data, 2002

Watson and Schopp (2009)

Not used


Mean population density, people per square mile, 2000 census block data

area-weighted mean

2000 U.S. Census block group data:

Watson and Schopp (2009)



Percent of area covered by water and wetland.

percent of area

Percentage of area covered by water and wetlands, as interpreted from National Land Cover Dataset (NLCD) land-use data, 2002 

Watson and Schopp (2009)



Average soil permeability in inches/hour

area-weighted mean

Soil characteristics from Soil Survey Geographic Data base (SSURGO) (Natural Resources Conservation Service, 2007)

Watson and McHugh (SIR 2014-5004)



Mean monthly precipitation for April, in inches.

area-weighted mean

Precipitation data (PRISM Climate Group, 2006)

Watson and McHugh (SIR 2014-5004)



Mean monthly precipitation for June, in inches.

area-weighted mean

Precipitation data (PRISM Climate Group, 2006)

Watson and McHugh (SIR 2014-5004)



Percentage of impervious area determined from NLCD 2011 impervious dataset

area-weighted mean

NLCD 2011 imperviousness grid


Percentage of urban land cover determined from NLCD 2011 land cover dataset

percent of area

NLCD 2011, codes 21-24


Additional Information

Watson, K.M., and McHugh, A.R., 2014, Regional regression equations for the estimation of selected monthly low-flow duration and frequency statistics at ungaged sites on streams in New Jersey: U.S. Geological Survey Scientific Investigations Report 2014–5004, 59 p.,

StreamStats for New Jersey can be used to estimate monthly flow-duration and monthly low-flow frequency statistics for ungaged streams in Coastal Plain and non-coastal regions of New Jersey for baseline and current land- and water-use conditions. The equations were developed to estimate 87 different streamflow statistics, which include the monthly 99-, 90-, 85-, 75-, 50-, and 25-percentile flow-durations of the minimum 1-day daily flow; the August–September 99-, 90-, and 75-percentile minimum 1-day daily flow; and the monthly 7-day, 10-year (M7D10Y) low-flow frequency. The report below presents the regression equations used to estimate the monthly flow-duration and monthly low-flow statistics, describes the errors associated with the estimates, and describes the methods used to develop the equations and to measure the basin characteristics used in the equations. Users should familiarize themselves with the report before using StreamStats to obtain estimates of streamflow statistics for gaged and ungaged sites.

The New Jersey StreamStats introductory page here has additional information regarding the application, including links to reports, cooperators, and other explanatory information.

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