Lift design and construction are different at various dams, but the basic principles are the same.
A fish lift is much like an elevator for fish. In simple terms, migratory fish swim into a hopper located at the dam and are lifted to an exit channel where they continue their upstream journey. The fish are attracted to the hopper by currents created by a strategic release of water. Shad and other migratory fish are then identified and counted as they pass by a viewing window.
Like many other migratory fish, American Shad spend most of their lives at sea and enter freshwater only to spawn. In Mid-Atlantic States, spawning occurs in the spring. Juveniles grow in the river until autumn when they migrate to the sea. Once in the open ocean, young shad join shad schools from other rivers and begin their seasonal migrations up and down the East Coast. Shad mature at sea in three to five years when they return to their rivers of birth to repeat the spawning cycle.
Migratory Fish Restoration and Passage On the Susquehanna River
Why restore the American Shad to the Susquehanna? Migratory fish are part of Pennsylvania's natural, cultural and economic heritage. Restoration efforts have been driven by this fact since the late 1800's. These efforts are simply aimed at reversing the effects of earlier human activity so the natural balance of nature can be restored.
Few Pennsylvanians are aware that the American Shad once ruled the waters of the Susquehanna River and its tributaries. Their abundance made for bountiful harvests each spring during their spawning runs. They were one of the region's most valued commodities for commerce and daily living through the early 1900's. Salt, maple sugar, cider, whiskey, leather, and grain are just a few of many commodities traded for American Shad during the heyday of shad fishing on the river. Shad, river herring and eels were all-important sources of food for Native Americans for centuries. Unfortunately, the shad's once natural migration cycle, voyaging hundreds of miles from the Atlantic Ocean through the Chesapeake Bay to the upper reaches of the Susquehanna, was broken as a result of economic development, including the construction of hydroelectric dams. By the 1920's, there were no shad to be harvested on the Susquehanna.
Since the early 1950's a partnership of electric utilities, government agencies and environmental and sporting groups have worked together to restore the American Shad to the Susquehanna.
In 1979, a plan was developed by various government agencies with a goal to reopen the river to natural migrations and restore annual spawning populations. Long-term operating licenses for all four Susquehanna River hydroelectric projects were renewed by the Federal Energy Regulatory Commission in 1980. As part of this relicensing all parties were urged to negotiate a settlement that would meet their common purpose of designing and implementing a cost-effective program to increase the number of shad returning to the Susquehanna River.
In 1984, Pennsylvania Power and Light Company, Safe Harbor Water Power Corporation and York Haven Power Company provided $3.7 million over a 10-year period (1985-94) to fund trap and transport of adult shad, expand hatchery operations and conduct other studies related to shad restoration. All three parties agreed to resolve outstanding issues related to the design and construction of fish passage facilities once Philadelphia Electric Company initiated construction of a permanent fish passage facility at Conowingo Dam.
With the start of Conowingo's east lift in 1991, the Safe Harbor and York Haven plants were encouraged to reach a final settlement with government agencies to construct permanent fish passage facilities by Spring 1997, and at York Haven by Spring 2000. In 1993, an agreement was reached between all parties to meet this target date. Despite severe damage to fish passage construction sites during an ice flood in January 1996, the Holtwood and Safe Harbor lifts were completed and in service on time. Between 1997 and 1999, 75 to 98 percent of the shad lifted at Holtwood also were passed at Safe Harbor. However, passage rates of shad from Conowingo to Holtwood have been only 30 to 50 percent, suggesting that fish are having difficulty moving upstream in the waters of the Conowingo pool. During the 2000 migration season, Conowingo passed 153,000 shad; Holtwood - 29,000; Safe Harbor - 21,000 and York Haven - 5,000.
The 15-year program of trapping fish at Conowingo and trucking them upstream ended in 1999, with about 230,000 American Shad having been trapped and transported. Completing the York Haven facility in time for the Spring 2000 run has provided shad with access to 435 miles of unobstructed river and major tributaries. With completion of the fish passages at the four hydroelectric dams, the hydro owners' funding of the shad restoration program has ended. Since first participating in the restoration program in the early 1960's, the owners of the four hydro dams have spent almost $60 million to construct fish passage facilities and an estimated $15 million more for studies, hatchery operations, fish transport and fish lift operations.