Merrill Creek Reservoir: New Jersey's Deepest Man-Made Lake
Nestled in Harmony Township within central Warren County, the Merrill Creek Reservoir is a remarkable feat of engineering and a sanctuary for nature lovers. Spanning 650 acres, this artificial lake is more than just a scenic destination; it is a critical component of the region's water management system, designed to hold 15 billion gallons of water while preserving the surrounding ecosystem.
The reservoir is enveloped by 290 acres of protected fields and woodlands, which are part of a larger 2,000-acre expanse of open space. This blend of industrial purpose and natural beauty makes it a unique landmark in the Garden State.
Engineering and Purpose
Completed in 1988, the reservoir was constructed by a consortium of seven electric utilities known as the Merrill Creek Owners Group. This group includes Public Service Electric and Gas (which handled the construction), Jersey Central Power and Light, Atlantic City Electric, Metropolitan Edison, Philadelphia Electric, PPL Corporation, and Delmarva Power and Light.
The project was mandated by the Delaware River Basin Commission to offset water lost through evaporation during the cooling processes of 14 power plants. To achieve this, the reservoir is connected to the Delaware River via a tunnel located approximately 3 miles away.
The Mechanics of Water Flow
The system operates on a seasonal cycle to balance environmental needs with energy demands. During the spring, when the Delaware River flow is abundant, the reservoir draws water. In the summer, when river levels are typically low and electricity demand for air conditioning peaks, the reservoir restores water back into the river.
This process serves a secondary vital purpose: by maintaining a steady flow in the Delaware River, it minimizes seawater intrusion—the movement of saline water into freshwater aquifers—which protects the drinking water supply for South Jersey communities, including Camden.
Construction Milestones
With a cost of $217 million, this was one of the largest construction projects in the United States during the 1986-87 period. The site was cleared using massive tree-eating machinery, and crews worked two 12-hour shifts to complete the two dikes and the earthen Merrill Creek Dam. The dam stands 280 feet high with a crest length of 1,140 feet.
A Haven for Wildlife and Recreation
Beyond its industrial utility, the reservoir is a premier destination for outdoor enthusiasts. While gasoline motors are prohibited to preserve the environment, launching facilities are available for recreational boating.
The surrounding parkland is home to a diverse array of wildlife, including white-tailed deer, wild turkey, crows, and bald eagles, as well as various migratory birds.
World-Class Fishing
Merrill Creek is most famous for its brown trout fishing. Because it is the deepest man-made lake in New Jersey—reaching a maximum depth of 225 feet—it provides the cold-water environment necessary for lake trout to survive year-round. It is one of only two lakes in the state where lake trout exist, the other being Round Valley Reservoir.
Since 2018, the lake has also been stocked with landlocked Atlantic salmon. Other species found in the reservoir include:
- Walleye and Yellow Perch
- Smallmouth and Largemouth Bass
- Chain Pickerel and Crappie
- Catfish, Sunfish, and Carp
- Rainbow, Brook, and Lake Trout
Education and Culture
The on-site visitor center serves as a hub for community learning, featuring exhibits on natural history and culture. It offers environmental education programs tailored for all ages, from pre-K students to adults.
Key Facts
- Location: Harmony Township, Warren County, New Jersey.
- Surface Area: 650 acres.
- Maximum Depth: 225 feet (Deepest man-made lake in NJ).
- Capacity: 15 billion gallons of water.
- Dam Height: 280 feet.
- Primary Purpose: Replacing evaporated river water for power plant cooling.
- Key Species: Brown trout, Lake trout, and landlocked Atlantic salmon.
| Feature | Detail |
|---|---|
| Lake Type | Artificial Reservoir |
| Construction Year | 1988 |
| Construction Cost | $217 Million |
| Protected Land | 290 acres (within 2,000 acres of open space) |
| Dam Length (Crest) | 1,140 feet |
Frequently Asked Questions
What is the primary purpose of the Merrill Creek Reservoir?
The reservoir was built to store water from the Delaware River during the spring and release it during the summer. This replaces water lost to evaporation from 14 power plants and helps maintain river flow during high electricity demand periods.
Can I use a motorboat at the reservoir?
Launching facilities are provided for boating; however, gasoline motors are strictly prohibited to protect the environment.
Why is the depth of the lake significant?
At 225 feet, it is the deepest man-made lake in New Jersey. This depth allows cold-water species, specifically lake trout, to survive throughout the entire year.
How does the reservoir help South Jersey's drinking water?
By maintaining a consistent flow in the Delaware River, the reservoir helps prevent seawater from intruding into the freshwater aquifers that provide drinking water to communities like Camden.
What fish can I catch at Merrill Creek?
The reservoir is best known for brown trout, but it also hosts lake trout, landlocked Atlantic salmon, walleye, bass, pickerel, and several other species.