Kirkwood-Cohansey aquifer

Kirkwood-Cohansey aquifer
Name	Kirkwood-Cohansey aquifer
Location	New Jersey
Type	Unconfined sand aquifer
Area	~3,000 km2
Primary aquifers	Pine Barrens
Coordinates	39°40′N 74°40′W

Kirkwood-Cohansey aquifer The Kirkwood-Cohansey aquifer underlies large portions of the New Jersey Pinelands and supports municipal, agricultural, and ecological water demands across southern New Jersey. It is a shallow, unconfined sand and gravel groundwater system within a landscape characterized by bogs, ponds, and slow-draining streams of the Mullica River, Barnegat Bay, and nearby coastal estuaries, and plays a central role in regional water supply, wetland hydrology, and conservation planning involving agencies such as the New Jersey Department of Environmental Protection and the United States Geological Survey.

Overview

The aquifer is composed of Pleistocene and Holocene sediments mapped by the United States Geological Survey and studied in environmental reviews for the New Jersey Pinelands Commission and the National Park Service. It functions as both a potable resource for communities like Atlantic City, Toms River, and parts of Camden County and as the principal hydrologic support for ecologically important areas including the Wharton State Forest and sections of the Delaware Bay and Barnegat Bay watersheds. Management involves coordination among the New Jersey Department of Environmental Protection, county water authorities, federal agencies such as the Environmental Protection Agency (EPA), and non-governmental organizations including the Pinelands Preservation Alliance.

Geology and Hydrogeology

The stratigraphy reflects deposits associated with the Kirkwood and Cohansey depositional units, comprising coarse sands, fine sands, silts, and peat layers identified in borehole logs held by the USGS and state geologists. Hydraulic properties have been quantified in studies funded by the National Science Foundation and the USDA, showing high permeability and transmissivity in the sand units, with variable specific yield that influences recharge and discharge dynamics toward the Mullica River and coastal estuaries. Groundwater flow is driven by topographic gradients toward the Atlantic coast and tidal influence in lower-elevation areas, with sea-level change documented in Intergovernmental Panel on Climate Change reports affecting saline intrusion risk studied by university researchers at Rutgers University and the Princeton University hydrology group.

Extent and Hydrologic Characteristics

Covering roughly the extent of the New Jersey Pine Barrens physiographic province, the aquifer underlies counties such as Burlington, Ocean, Atlantic, and parts of Camden and Cumberland. Surface-water connections include tributaries of the Rancocas Creek, Great Egg Harbor River, and Tuckerton Creek, while groundwater-surface exchange influences conditions in the Barnegat Bay National Estuary Program and the Delaware River Basin Commission planning areas. Seasonal fluctuations respond to precipitation patterns affected by systems tracked by the National Oceanic and Atmospheric Administration and historical droughts documented in state water-supply plans.

Ecology and Surface-Water Interaction

The aquifer’s discharge sustains acid bogs, pocosins, and cedar swamps that host species protected under state and federal law, including habitat for the Delaware Bay migratory shorebirds, the timber rattlesnake, and rare plants noted by the New Jersey Natural Heritage Program. Hydrologic support maintains water levels in kettle ponds and vernal pools important for amphibians studied by the New Jersey Audubon Society and supports estuarine salinity regimes in the Barnegat Bay and Great Bay complexes cataloged by the National Estuarine Research Reserve network. Surface-water interaction is modulated by impediments such as historic drainage ditches installed under county and municipal road projects administered by county engineers and by land-cover changes influenced by planning decisions from local governing bodies.

Water Use and Management

Municipal withdrawals are managed through permits issued by the New Jersey Department of Environmental Protection and regional water authorities including the South Jersey Water Cooperative and county water utilities; industrial and agricultural users obtain allocations tied to water-resource planning documents evaluated by the New Jersey Water Supply Authority. Groundwater modeling for allocation and drought contingency uses tools developed by the USGS and academic partners, with stakeholder engagement that includes county planning boards, the Pinelands Commission, and regional conservation NGOs. Infrastructure investments by municipal governments and public utilities aim to balance supply reliability for towns such as Pleasantville and Glassboro with environmental flow needs.

Environmental Issues and Threats

Threats include nutrient loading from septic systems regulated under the New Jersey Department of Health codes, fertilizer and pesticide runoff from agriculture overseen by the New Jersey Department of Agriculture, and contaminant plumes from industrial sites tracked under the Comprehensive Environmental Response, Compensation, and Liability Act program administered by the EPA. Sea-level rise projections from the IPCC and storm-surge impacts examined after events like Hurricane Sandy increase the risk of saline intrusion and infrastructure damage, while urbanization pressures traced in county master plans and municipal zoning ordinances fragment recharge areas. Invasive species issues and shifting fire regimes also intersect with land management by the New Jersey Division of Parks and Forestry.

Monitoring, Research, and Conservation

Long-term monitoring networks operated by the USGS, the New Jersey Geological Survey, and university researchers at Rutgers University provide groundwater-level, water-quality, and isotopic data used in peer-reviewed studies published in journals managed by professional societies such as the American Geophysical Union and the Hydrogeology Journal. Conservation initiatives coordinated by the Pinelands Preservation Alliance, the Nature Conservancy, and state agencies focus on protecting recharge zones through land acquisition, conservation easements, and managed land-use policies embedded in the Pinelands Comprehensive Management Plan. Ongoing research priorities include coupled surface-groundwater modeling supported by grants from the National Science Foundation and resilience planning linked to federal programs administered by the Federal Emergency Management Agency.

Category:Aquifers of New Jersey