Harnessing Nature: How Hydropower Dams like Lake Wallenpaupack Work and Serve Their Communities

Lake Wallenpaupack: A Legacy of Purpose

Lake Wallenpaupack was created in 1926 by the Pennsylvania Power & Light Company (now PPL Corporation) through the construction of the Wallenpaupack Dam on Wallenpaupack Creek. The lake stretches 13 miles long, covers 5,700 acres, and has a shoreline of over 52 miles. It was specifically designed to generate hydroelectric power and manage water levels during peak demand periods. Today, the lake serves multiple purposes. While it continues to generate electricity through a regulated hydroelectric facility, it also supports wildlife, recreation, and local tourism. PPL later transferred management of the lake’s recreational facilities to the local community, but it still retains oversight of dam operations and energy production.

Seasonality and Strategic Water Releases

Hydropower is unique in its responsiveness. Unlike solar or wind, which depend on variable weather conditions, hydroelectric systems can ramp production up or down by controlling water flow. This makes dams ideal for "peaking" power—supplying electricity during times of high demand.

During summer months, when air conditioning and cooling needs spike, hydro facilities (like those at Wallenpaupack) can release water to help meet energy demands. Operators coordinate closely with grid managers to time releases that coincide with peak afternoon usage, typically between 3 PM and 7 PM. These releases aren’t random. They're guided by seasonal forecasts, reservoir levels, and electricity demand. Operators must also account for recreational use of the lake, especially during holiday weekends, ensuring water levels remain sufficient for boating, swimming, and fishing.

Brookfield Renewable currently manages the water release schedule, and considers these factors when making plans:

• Boating Releases: Brookfield is required to offer eight summer releases with flows of 1,200 cubic feet per second (cfs) to support recreational activities like whitewater rafting on the Lackawaxen River.
• Timing & Conditions: These releases are typically scheduled after July 1, but may be altered due to maintenance at the hydroelectric plant. If natural river flows are too low, releases might be postponed or rescheduled.
• Electricity Generation: The dam powers two turbines that generate 44 megawatts, enough for about 35,000 homes. Water flows through a 3.5-mile pipe to the plant, spins the turbines, and exits into the river.

You can find real-time release data and alerts on SafeWaters’ Wallenpaupack page. It’s the go-to source for boaters and residents tracking lake levels and flow conditions.

Spring Thaw, Flood Management, and Winter Drawdowns

In spring, melting snow and seasonal rains increase water levels. Controlled releases help manage this influx, reducing the risk of downstream flooding. This is critical for protecting towns and properties located along rivers fed by the dam.

In colder months, lakes like Wallenpaupack may undergo a “drawdown,” a deliberate lowering of the water level. This serves multiple purposes:

• Ice damage prevention: Reducing water levels protects docks and shoreline structures from shifting ice.
• Dam maintenance: Winter is often used for inspecting and servicing dam infrastructure.
• Shoreline cleanup: Lower water levels expose debris and sediment, allowing communities to organize shoreline cleanups.

Protecting Turbines: Keeping the Good Out

While water is the working fluid of a hydroelectric system, dams must prevent unwanted elements—like fish, logs, debris, and sediment—from entering turbine systems, where they could cause mechanical damage or disrupt operations. Large steel grates known as trash racks are placed at water intake points to catch floating debris. These grates typically have vertical bars spaced just a few inches apart. Their job is to block branches, leaves, and litter while allowing water to flow freely into the penstocks.

Fish Screens and Passage Systems

Hydropower facilities have historically posed risks to aquatic life, especially fish species that migrate to spawn. Modern dams, however, are required to mitigate these risks through innovative technologies:

• Fish screens are fine mesh barriers that prevent small fish and eggs from being sucked into turbines.
• Bypass channels or fish ladders allow fish to travel around the dam, maintaining migratory paths. Some systems even use vacuum lifts or elevators for fish passage.

Lake Wallenpaupack’s dam, while not on a major migratory fish route, still uses environmentally mindful intake structures to reduce harm to aquatic ecosystems.

Benefits to Local Communities

Beyond generating electricity, hydro dams and their associated lakes offer wide-ranging benefits to nearby towns and residents.

1. Renewable, Carbon-Free Energy: Hydropower produces electricity without burning fossil fuels, making it one of the cleanest forms of energy. It doesn’t release greenhouse gases during operation and helps reduce reliance on coal or gas plants, which pollute air and contribute to climate change. The energy from Wallenpaupack’s hydro station feeds into the regional grid, benefiting thousands of Pennsylvania residents with clean, dependable power.
2. Flood Control and Water Management: By storing and releasing water strategically, dams help regulate river flow and prevent flash flooding during storms or snowmelts. Communities downstream are better protected from water-related disasters.
3. Economic and Tourism Boost: Lakes like Wallenpaupack are economic engines for their regions. They support:
   • Tourism: Boating, fishing, jet-skiing, paddleboarding, and kayaking.
   • Hospitality: Rental homes, resorts, lodges, and campgrounds.
   • Small businesses: From bait shops and marinas to restaurants and guide services.
4. Educational and Environmental Stewardship: Many dam operators, including those managing Wallenpaupack, partner with local schools and conservation groups to promote environmental education. Students and visitors learn about energy, ecology, and sustainability through field trips and interpretive programs. Community cleanups, shoreline preservation efforts, and volunteer monitoring projects foster a sense of stewardship and appreciation for the lake’s natural resources.