Simulation of ground-water flow and pumpage in Kings and Queens Counties, Long Island, New York

Water-Resources Investigations Report 98-4071

Prepared in cooperation with the New York City Department of Environmental Protection
ORCID iD and



The potential effects of using ground water as a supplemental source of supply in Kings and Queens Counties were evaluated through a 4-layer finite-difference ground-water-flow model with a uniform grid spacing of 1,333 feet. Hydraulic properties and boundary conditions of an existing regional ground-water-flow model of Long Island with a uniform grid spacing of 4,000 feet were refined for use in the finer grid model of Kings and Queens Counties. The model is calibrated to average pumping stresses that correspond to presumed steady-state conditions of 1983 and 1991. A transient-state simulation of the year-by- year transition between these two conditions was also conducted.

Pumping scenarios representing public-supply withdrawals of 100, 150, and 400 million gallons per day (Mgal/d) were simulated to determine the duration of sustainable pumpage, defined as the length of time before a particular pumping rate induces landward hydraulic gradients from areas of salty ground water. The simulations indicate the following hydrologically feasible scenarios:

(1) Pumpage of 100 Mgal/d could be sustained for about 10 months, followed by a 46-month period of pumping at reduced (1991) rates, to allow water levels to recover to 90 percent of 1991 levels.

(2) Pumpage of 150 Mgal/d could be sustained for about 6 months, followed by a 79-month period of pumping at a reduced (1991) rate.

(3) Pumpage of 400 Mgal/d could be sustained for about 3 months from an initial condition of maximum aquifer storage.

Each of these scenarios could be modified by injecting surplus water from upstate reservoirs, available from January to May, into the proposed wells. Injection at half the pumpage rate during the recovery period reduces the recovery period to 14 months in scenario 1, 6 months in scenario 2, and 9 months in scenario 3.

Suggested Citation

Misut, P.E., Monti, Jack, Jr., 1999, Simulation of ground-water flow and pumpage in Kings and Queens Counties, Long Island, New York: U.S. Geological Survey Water-Resources Investigations Report 1998–4071, 50 p.,

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Hydrogeology
  • Simulation of ground-water flow
  • Simulations of proposed pumping scenarios
  • Summary
  • References cited
  • Appendix A: Locations and pumping rates of wells used in the Kings-Queens model
  • Appendix B: Difference between simulated and measured water levels at selected wells

Additional publication details

Publication type:
Publication Subtype:
USGS Numbered Series
Simulation of ground-water flow and pumpage in Kings and Queens Counties, Long Island, New York
Series title:
Water-Resources Investigations Report
Series number:
Year Published:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
New York Water Science Center
v, 50 p.
United States
New York
Kings County, Queens County
Other Geospatial:
Long Island
Online Only (Y/N):
Additional Online Files (Y/N):