Entrance into Beaver Dam Cave

Inside Beaver Dam Spring 2005

Beaver Dam along Drowning Creek

Richard Stark of the Oklahoma ES Field Office and Steve Hensley, manager of the Ozark Plateau National Wildlife Refuge met with Sam Ziara of the Grand River Dam Authority (GRDA) and Steven Nolan of the U. S. Army Corps of Engineers to discuss the effects of the operation of Grand Lake on the federally-listed endangered gray bat Myotis sodalis.  Water levels in two important gray bat caves, Twin and Beaver Dam Caves, which are located in close proximity to each other, are affected by water levels in Grand Lake.  The Federal Energy Regulatory Commission (and GRDA) and the Corps control the power and flood pools of the reservoir, respectively.  The Service anticipates take of gray bats within Beaver Dam Cave near Grand Lake due to flooding associated with lake operation.  The Service has previously consulted with the FERC and prepared a BO pursuant to section 7 of the Endangered Species Act (ESA) for the re-licensing of the Pensacola Hydropower Project at Grand Lake in Oklahoma in 1992.  The Corps was not involved in the consultation.  Take also may occur in Twin Cave, but the water level correlation at this site is not well understood at this time.  The Service, Corps, and GRDA (for the FERC) discussed the need to monitor 1) water level fluctuations in Twin Cave, and 2) gray bats use of the two caves during summer 2007 to answer several questions.  These questions include whether there is one bat colony that utilizes each cave seasonally and moves between the closely located caves, or if each cave is being used by a separate colony.  The Corps, GRDA, and the Service are currently developing a Scope of Work and Transfer Fund Agreement for gray bat monitoring efforts this summer.  Future coordination regarding necessary gray bat and water level monitoring is anticipated.  Further section 7 consultation with the Corps will be necessary since they were not involved in the previous consultation and their control of the flood pool could result in take.  Re-initiation of formal consultation with the FERC would be necessary if information gathered during upcoming monitoring efforts indicates the amount or extent of take from the project may be exceeding the level anticipated in the incidental take statement of the 1992 BO.