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Group 2 Delaware River Watershed Initiative


Kirkwood-Cohansey Aquifer

This cluster of watersheds is defined by a shared connection to the Kirkwood-Cohansey aquifer in New Jersey’s outer coastal plain, including much of southern New Jersey’s portion of the Delaware River watershed.

The aquifer underlies nearly two million acres—about one-third of the state— encompassing two large landscapes that have been the focus of effective conservation efforts for decades. These landscapes are the Pinelands, a globally significant biosphere recognized by the United Nations and designated by both the federal and state governments for extraordinary protection, and the Delaware Bayshore region, which includes New Jersey’s largest concentration of farmland.

Within the Pinelands are four major river systems. The largest is the Mullica River watershed— encompassing the Mullica, Wading, Batsto and Oswego Rivers—which empties into Great Bay and ultimately the Atlantic Ocean. The second largest is the Rancocas Creek watershed, which drains west into the Delaware River. The Great Egg Harbor River watershed, including the Great Egg Harbor and Tuckahoe Rivers, drains into the Atlantic Ocean. In addition, several small rivers in the Bayshore portion of this cluster flow through extensive agricultural areas and deliver fresh water into the brackish lower Delaware River and the Delaware Bay, including the Salem, Maurice and Cohansey Rivers.

Drinking Water Source 1m residents and millions of seasonal visitors
Total Area 2,119 Sq. Mi.
Protected Land 47% Protected

Major Threats

Development of Forested Land
Expanding suburban development and cropland is leading to contamination of ground and surface water. Increased impervious area and the loss of natural storage and other forest ecosystem services contribute to high volumes of run-off contaminated by nutrients from suburban lawns, faulty septic systems and agriculture. Land alteration opens areas to non-native, invasive species and creates new deer habitat, displacing or destroying plant life that is important to the health of the watershed.

Aquifer Depletion
Pumping water for human uses has lowered the water table, dried wetlands, lessened stream flow and reduced freshwater discharge to coastal estuaries. Because of the increase in impervious area, aquifer recharge is insufficient, jeopardizing the sustainability of the water supply and putting the region at risk from saltwater intrusion and rising sea levels.

Poor Forest and Wetland Stewardship
Motorized recreation, suppression of natural wildfire, inadequate control of invasive plants and deer populations, and other practices have degraded habitats and diminished native biodiversity—even on land that has been permanently preserved.

Why it’s Important

The Kirkwood-Cohansey aquifer supplies virtually all the water in the streams, rivers, ponds and wetlands of southern New Jersey. It also provides more than 45 billion gallons of water each year to over a million residents, visitors, farms and other businesses. Farmers depend on ground water for irrigation, and the region’s cranberry industry uses vast amounts of aquifer water to maintain its bogs. The aquifer, however, is threatened by systematic over-pumping to serve human demands, and by pollution associated with urban/suburban development and agricultural use.

In 2009, there were almost 3,000 wells (not including private domestic wells) withdrawing a total of more than 125 million gallons of water per day. This intense pumping lowers the water table, dries up wetlands, reduces stream flows and depletes freshwater flows to coastal estuaries. Most importantly, it depletes the aquifer itself.

Along with impacts on human consumption, the depletion of the aquifer and its river systems cause changes in plant and wildlife populations, including the loss of rare species that live in affected surface waters and wetlands. Most streams fed by the Kirkwood-Cohansey aquifer (63 percent) are impaired by one or more contaminants, including fertilizers and pesticides. Urban/suburban development and farming also generate polluted stormwater and agricultural run-off and rob the aquifer of the filtering and recharge functions natural vegetation provides.

Although much of the land in the Pinelands has some degree of regulatory protection through the Pinelands Plan, under the Pinelands Protection Act of 1979, these protections could be lost if the Pinelands rules are changed or revoked. As of 2007, about 743,000 acres of the aquifer’s area that is not preserved, developed or in wetlands was in private ownership, giving it high potential for development. In addition, although many acres of the Bayshore are permanently protected, most are not. In both parts of this cluster, unprotected land is subject only to local zoning and will likely be developed if not preserved.

What We Can Do

The cluster organizations selected six focus areas for their importance to the protection and restoration of the tributary streams and groundwater resources that supply the Delaware River watershed with an adequate supply of clean water. The Southwest Branch of the Rancocas Creek is an important tributary to the lower Delaware River that is a largely intact Pinelands ecosystem imperiled by suburban development. The Core Pine Barrens and Greater Hammonton priority areas fall outside the Delaware River watershed boundary but are key to the health of the Pinelands and the interconnected aquifer, representing both pristine forests and a state-designated growth area. The Salem River, Cohansey-Maurice, and Western Cape May priority areas of the Bayshore region contain important targets for both agricultural restoration and groundwater conservation.

The cluster organizations will work to secure protection of 6,500 acres of recharge area, restoration of 9,000 feet and 300 acres of stream corridor and, through a public awareness effort, reduction of groundwater consumption by 3 percent. Cluster organizations will:

  • Protecting priority farmland and ensuring that on-farm practices minimize impacts on soil and water.
  • Engaging private landowners in agricultural, forest and stream-related best management practices—including federal incentive programs—and promoting policies that protect groundwater and watershed health.
  • Educating the citizens and authorities in Bridgeton and Hammonton about ways to conserve water and manage stormwater through a low-impact development program.
  • Reducing septic seepage into the aquifer through a targeted outreach campaign to inform property owners and renters about septic maintenance practices; and working with town officials to plan upgrades, host workshops and presentations, and create publications to educate local officials on septic system maintenance for clean water.
  • Preserving at least 68 acres of forest on priority parcels along the Cohansey-Maurice Rivers, and 400 acres along the southwest branch of the Rancocas.

Monitoring and Measurement

Data collected for project-specific monitoring includes the number of acres preserved, damaged habitats restored, per capita waterusage in the focus areas, and individuals participating in outreach and engagement projects. In many cases, impacts on water table levels, water chemistry and biological communities will be difficult to measure directly. These assessments require advanced professional expertise because these projects relate to a large area and either the effects of any given action may take years to develop or it may not be possible to isolate the effects of the project from a “noisy” natural system.

In some cases, however, the nature of a project lends itself to direct measurements. In such cases, it will be appropriate to monitor acidity, aquatic plant and fish communities, nitrogen and phosphorous levels, and aquifer withdrawals. Although complex, efforts to define and implement an effective monitoring plan for the aquifer can be a powerful organizing tool to galvanize improved protections in the Pinelands and the Bayshore for the groundwater that supports these unique landscapes.


Timeline and Investment

As of January 2014, estimated costs to protect critical landscapes, restore farmland, address policy issues and engage in outreach were nearly $24 million through 2017, with agricultural and ecological restoration totaling $12.5 million, land protection totaling $8.5 million and outreach initiatives totaling nearly $3 million. Work began in 2014 with $2.4 million in grants from the William Penn Foundation with additional support available through competitive re-grant funds for land protection and restoration.