Tenkiller Ferry Dam is located about 85 miles southeast of Tulsa, Oklahoma at RM 12.8 on the
Illinois River. The dam is used to provide flood control, hydropower, water supply and
recreational benefits to the region. Historically, Tenkiller Ferry Reservior
had experienced
significant periods (up to four months) of extremely low dissolved oxygen (DO) concentrations
that could raised serious concern for downstream aquatic life. As a result of
these conditions, the turbines have
often been operated at reduced capacity to induce aspiration of air through the vacuum breaker.
This venting operation can improve release DO concentrations significantly, but the plant
derating is costly and reduces flexibility in plant operation.
To improve low DO concentrations in releases from the dam and to restore full
hydropower capacity and flexibility,
a study was undertaken to determine if the use of an aerating weir downstream of the
project would be justified. It was determined that weir designs were available that could
achieve the objective of improved DO concentrations. However, it was discovered
that, when in use, these weirs caused a backwater effect on the turbines
and reduced the net head on the turbine by about 3 percent.
The Power Branch was part of the study to determine the impact of the various weir configurations on the power generation
and the economic losses associated with the reduced power generation.
