Long Island Freshwater

Science Center Objects

Long Island is surrounded by an almost limitless amount of saltwater in the Atlantic Ocean, in the Long Island Sound, and in the many bays bordering Long Island. Although the salty water is important to the economy of the area and is of significant recreational value, this website is mainly concerned with the fresh water of Long Island, which from many standpoints, is even more important than the salty water.

When rain falls to the ground, the water does not stop moving. Some of it flows along the land surface to streams or lakes as "runoff", some is used by plants and is transpired back to the atmosphere, some evaporates and returns to the atmosphere, and some seeps into the ground as “recharge”.

As water seeps into the ground, some of it clings to particles of soil or to roots of plants just below the land surface in what is termed the “unsaturated zone”. This moisture provides plants with the water they need to grow. Water not used by plants moves deeper into the ground as “recharge”. This water moves downward through empty pore spaces in the sand and gravel that comprise the aquifers until it reaches the zone of saturation, where 100 percent of the pore spaces are filled with water. The top of this saturated zone in the uppermost aquifer is called the water table and the water that fills the pore spaces of the aquifer is called groundwater (Clark and Briar, 1993). 


Table of Contents

State of the Aquifer, Long Island, New York - Introduction

Location and Physical Setting


  1. Hydrolgeologic Units
  2. Fresh and Saltwater Relations/Interactions

State of the Aquifer System

  1. Precipitation
  2. NWIS - the USGS Data Archive 
  3. Surface Water - Streamflow
  4. Groundwater Levels
  5. Water Table and Surface Maps
  6. Water Use
  7. Groundwater Budget
  8. Inflow to the Groundwater System
  9. Outflow from the Groundwater System
  1. Case Studies

Interactive Content