F.E.W dam was constructed in 1961 by the United States Army Corps of Engineers (ACOE) for flood control. The dam consist of one release tower which has the primary outflow gate which draws from the very bottom of the lake. While it has done an outstanding job in migrating flood damage along the Lehigh river, its limitation in only being able to draw water from the lake bottom (with the exception of a small 250 CFS by-pass gate from the top of the lake) means that F.E.W. dam can not conserve the cold water at the bottom of the lake for when its needed most in the warm summer months. While it has created essentially a cold water ecosystem, the fact that the cold water typically runs out by Mid June means that this cold water ecosystem has not fully developed.
A big breakthrough was obtained in 1998 when congress authorized recreation as a second mission of the dam. This led to LCFA and other groups working closely with the Army corps to design annual flow plans which conserve the cold pool for as late in the season as possible (usual by mid June) and adds minimum flow levels during the summer months. This helps cool the river below the dam during the critical months when water temps can exceed 70 degrees. Once water temps exceed 70 degrees, cold water species such as trout begin to stress. When temps exceed 75 degrees, then the mortality rate increases substantially. These flow plans have been one of the biggest contributions to growing and supporting the wild trout population in the Lehigh river.
One of the major missions of the LCFA is to complete a feasibility study that would show that making structural changes to the release tower would create a substantial tailwater fishery for nearly 30 miles below the dam. In creating this world class tailwater fishery, it could bring in millions to the local economy through the fishing and recreational industry. It would also create what amounts to a massive spring creek of cold water which results in higher water quality, and those municipalities depend on it for a source of drinking water. In comparison, a recent study shows the Upper Delaware River system brings in approximately 400+ Million to the local economy through its recreational fishery created by the dams on that river. Its ranks as one of the top five tailwaters in the country.
We have an incredible opportunity to elevate the Lehigh river, and the LCFA continues to work to accomplish that mission.
RECREATION FLOW PLAN
Since 2005 the Army Corps of Engineers (ACOE) releases an annual recreational flow plan which outlines the proposed schedule of water releases through the utilization of the season increase (70' additional feet) of water storage in the F.E.W. reservoir. These releases serve two purposes.
Conserve cold water for summer months as well as increase minimum flows for the purposes of conservation and enhancing the fishery.
Whitewater is released for commercial and recreational purposes.
The ACOE also provides a valuable Inflow/Outflow chart showing the current state of the reservoir levels.