Press Releases

USACE Announces changes to the Revised Interim Operations Plan (RIOP) for Jim Woodruff Lock and Dam

Published May 22, 2012

MOBILE, Ala. – The U.S. Army Corps of Engineers (USACE), Mobile District announced today they have implemented changes to the Revised Interim Operations Plan (RIOP) for Jim Woodruff Lock and Dam which addresses water management operations at the dam and releases into the Apalachicola River.  These changes were made after more than a year of formal consultation with the U.S. Fish and Wildlife Service (USFWS) on operations to protect listed threatened and endangered species and their critical habitat in the Apalachicola River.

“We reinitiated consultation with USFWS on the RIOP in November 2010 because of new information that became available regarding the distribution and mortality of certain mussel species that was not available during our previous consultations,” Public Affairs Officer E. Patrick Robbins said. “During our previous consultations we did not expect mussels to re-populate in locations above the minimum 5,000 cubic feet per second (cfs) flow.  In September 2010, we learned this in fact did occur and that mussels were exposed and died as the river stage declined. Therefore, our latest consultation focused on identifying additional avoidance and minimization measures when river stages and flows are between 5,000 and 10,000 cfs at Jim Woodruff.”

The changes being implemented under this consultation are very minor. They include having minimum flow releases match basin inflow between June and November when flows are between 5,000 and 10,000 cfs (previously the RIOP addressed releases between 5,000 and 8,000 cfs), and when normal operations are resumed if drought contingency operations are implemented.  The previous RIOP required normal operations resume when composite basin storage reached Zone 2, but the new changes move that level to Zone 1.

“Since we are already operating under drought contingency operations, stakeholders will not see any immediate change to operations as a result of these RIOP refinements,” continued Robbins.  “In fact, the first change will be that the reservoirs will need to reach levels which support a composite storage in the basin into Zone 1 before the current drought operations are suspended. During normal operations, the changes being implemented may result in lower reservoir levels by mere inches during flow conditions between 5,000 and 10,000 cfs.”            

The Biological Opinion which discusses the changes USACE is implementing along with the corresponding environmental analysis are available for public review on the Mobile District website at

E. Patrick Robbins

Release no. 12-012