Niagara Power Project — Common Tern Habitat Improvement Project
Summary
When the New York Power Authority’s (NYPA) Niagara Power Project produced its first power in 1961, it was the largest hydropower facility in the Western world. Today, the Niagara Power Project is the biggest electricity producer in New York State, generating 2,400 MW. Recently NYPA completed a project that benefits Common Tern (Sterna hirundo), a state-listed threatened bird species whose recovery has been hampered by the limited nesting habitat available in the region.
Subject to extreme wind and waves coming off of Lake Erie, existing breakwaters maintained by the U.S. Army Corps of Engineers provide, at best, marginal nesting habitat. NYPA and its design team developed two practical, innovative solutions to improve nesting for Common Terns. Thus, two state-of-the-art gravel nesting beds were designed and installed, one a 2,100 square-foot fixed installation mounted to one concrete breakwater end cell and another consisting of a 1,300 square-foot modified barge moored to another breakwater.
During 2009, monitoring indicated that both were highly successful, providing 3,400 square feet of improved nesting habitat that supported 550 new nests and over 1,000 fledgling chicks.
Background
The original license for the Niagara Power Project issued by the Federal Energy Regulatory Commission expired in late 2007. In 1999, with foresight in mind, NYPA initiated a collaborative relicensing process based on innovative concepts championed by the National Hydropower Association and the Hydro Reform Coalition. More than 100 stakeholders were involved in the Niagara Power Project relicensing to address a wide range of ecological, recreational and economic issues.
Among the ecological issues identified was the opportunity to develop additional stable habitat in the highly industrialized Buffalo/Niagara corridor for ecologically and recreationally important fish and wildlife species. As part of its settlement agreement, NYPA agreed to design and install a set of eight habitat improvement projects for such species.
While production of reliable hydroelectric energy provided many benefits, it also brought environmental consequences, including blocking the movement of your American eels migrating from the Atlantic Ocean to the upper St. Lawrence River and Lake Ontario. Mitigation to this impediment was provided in the 1970’s when Ontario Hydro (now Ontario Power Generation), the owner of the Canadian half of the International Power Project, installed an eel ladder on its portion of the Dam. The need for additional passage at the Dam was an issue raised by the U.S. Fish and Wildlife Service (FWS) and the New York State Department of Environmental Conservation (DEC) during the CCP relicensing process.
Of concern — especially to the New York State Department of Environmental Conservation (DEC) – was how to improve the quality and extent of nesting habitat for Common Tern. Tern populations have been on the decline since the 1980s because of the loss of suitable nesting habitat in the region, as well as disturbance by humans, and predation.
Past measure included the placement of a number of temporary, seasonal improvements to the breakwaters. Therefore, NYPA agreed to develop a more permanent and less labor-intensive approach to nesting site improvement. Installation of both Common Tern nesting improvements was completed in April 2009 at a cost of approximately $183,000.
Challenge
The breakwaters were designed to protect Buffalo Harbor from the massive wind, wave, and ice forces coming off of Lake Erie. In spite of robust construction of concrete and rock 10 to 15 feet above the water, the breakwaters were frequently overtopped by waves and ice, and even summer storms have severe impacts. Therefore, the Common Tern nesting habitat improvements needed to be strong enough to withstand the harsh weather conditions at the breakwaters without jeopardizing structural integrity or historic nature. A further concern was to ensure that the tern nesting habitat not interfere with the capability to fully and readily inspect and repair the breakwaters.
Another factor that complicated the installation was the timing of the nesting season. Terns in the Buffalo harbor area begin to nest very early in the spring, often about the same time ice in Lake Erie begins to break. There is only a very narrow window of time after the ice breaks but before the terns begin to nest in which access to the breakwaters is possible. At much risk, DEC crews in past years braved mid-March to early April waters each year to rebuild temporary nesting improvements on the breakwaters.
Innovation
Careful consideration and consultation with a wide range of stakeholders was needed, including the U.S. Army Corps of Engineers for permission to construct improvements on their breakwaters. NYPA and its design team of engineers and biologists included Kleinschmidt Associates (Pittsfield, ME), Riveredge Associates (Massena, NY), and Gomez and Sullivan Engineers (Williamsville, NY). The team conceived two Common Tern habitat improvement designs.
The first was the revised form of the fixed Common Tern nesting installation used in previous years. The second habitat improvement option was for a mobile design that creates nesting habitat on a barge that can be towed out to the harbor and moored to the breakwater for the nesting season. The purpose of this design is to rapidly deploy pre-constructed nesting habitat out to the breakwaters. The design also affords a completely new nesting location while improving an existing, marginal nesting area at the end of the nesting season, in mid-August, the entire barge can be removed from the breakwater.
Results
Installation of both Common Tern nesting improvements was completed in April 2009 at a cost of approximately $183,000. Rapid deployment enabled installation within a narrow window of ice-free conditions within Buffalo Harbor, thereby meeting one of the key design objectives.
Following construction of both the fixed and mobile nesting installations, terns immediately began nesting on the newly installed gravel. The first nest scrape was made within 24 hours of creating the installation. Terns quickly began nesting in large numbers, and a month after the gravel installation was complete, the end cell and tern barge had approximately 550 nests. These 550 nests represent a full third (34.0%) of all nests (1617) recorded in Buffalo Harbor for 2009. The end cell improvement contained 50% of all tern nests on this particular breakwater, more than had ever been recorded here. The barge contained an additional 225 nests in entirely newly created habitat.
Terns that nested on the end cell and barge had productivity (chicks fledged per nest) over five times higher than terns that nested on the cement sections of the breakwater. In 2009, many nests on the unimproved, bare cement failed due to high winds, waves, and flooding from rainstorms. In contrast, the gravel of the end cell and barge provided stable, well-drained substrate and productivity was very high.
Both fixed and mobile nesting improvements were deemed to be successful, and in total, over 1,000 tern chicks were fledged in 2009 on the gravel provided by the Common Tern Habitat Improvement Project. These birds will migrate to Central and South America and return to the Buffalo Harbor breakwaters at age two or three to breed themselves. As a result, the Common Tern Habitat Improvement Project is providing critically needed, high-quality nesting habitat for this state-listed threatened species.
Stakeholder Quotes
“NYPA worked collaboratively with Army Corps of Engineers regulatory staff and engineers on the project to improve Common Tern nesting habitat on the Corps’ breakwaters in Buffalo Harbor, developing designs that minimized impacts to the breakwaters yet allowed relatively easy access for future inspections and maintenance needs. NYPA completed the breakwater habitat project in April 2009, the same month that the Corps authorized it. NYPA kept the Corps sufficiently informed at all times, including during the construction process, post-construction site visits, and on the success of the nesting improvements.” — Robert W. Remmers, P.E., PMP, Chief, Operations and Technical Support Section U.S. Army Corps of Engineers, Buffalo District
