Interim Report III & IIIA:
Modified Structures and Operations & Acoustic Bubble Barriers
Introduction:
The U.S. Army Corps of Engineers (USACE) was directed in the Water Resources Development Act 2007 to conduct a study of a range of options or technologies for reducing impacts of hazards that may reduce the efficacy of the Electrical Dispersal Barriers located on the Chicago Sanitary and Ship Canal (CSSC).
To expedite the efficacy evaluation, USACE divided the study into several phases. These phases are outline in the ACRCC Framework. In June 2010, USACE and its partner agencies in the ACRCC released the interim III and IIIA reports for public review.
Overview of III: Modified Structures and Operations
The US Army Corps of Engineers is working with the other members of the Asian Carp Regional Coordinating Committee to find ways to reduce the risk of Asian carp migrating into Lake Michigan. One of the Corps' responsibilities is to operate the locks. This Interim Efficacy Report outlines how those structures can best be used to help impede Asian carp movement.
Interim III, Modified Structures and Operations, Chicago Area Waterways Risk Reduction Study and Integrated Environmental Assessment –presents an evaluation of the potential for risk reduction that might be achieved through potential changes in the operation of the Chicago Area Waterway structures, such as locks, sluice gates, and pumping stations.
The report includes an assessment of operational changes that could be implemented as needed by agencies that are responsible for fish management efforts such as electro-fishing, spot piscicide application, or intensive commercial fishing efforts by the U.S. Fish and Wildlife (USFWS) and Illinois Department of Natural Resources (IDNR).
The proposed modified operations at existing structures are designed to aid in preventing Asian carp migration, while also assuring the ability to use the locks by public health, life and safety agencies, such as the Chicago Fire and Police Departments, and the Department of Homeland Security. In addition to the importance of the locks as a water flow outlet for floods, they are also essential links for commerce and navigation, supporting waterborne commerce in the Chicago area.
USACE has worked with the navigation industry and others to assess the impact of lock and waterway closures on waterborne commerce. However, impact to navigation is only one factor that was considered, this report also considered potential impacts to the local and regional economy, and environment for the recommended plan.
The proposed modifications to structural operations will be used in conjunction with other measures such as intensified commercial fishing and implementation of more extensive monitoring and rapid response programs.
Overview of IIIA: Acoustic Bubble Barriers
Interim IIIA, Fish Deterrent Barriers, Illinois and Chicago Area Waterways Risk Reduction Study and Integrated Environmental Assessment considered how technologies such as bubbles, lights and sounds can be used to deter Asian carp movement.
USACE decided to evaluate whether and how these technologies might be used to enhance the efficacy of the electric barrier and to reduce the threat that a sustainable population of Asian carp could become established in the CAWS or in Lake Michigan. In the course of this evaluation, USACE determined that these technologies are more expensive and more time consuming to install and operate at appropriate parameters than first thought. While these technologies do show promise for use in the CAWS, they are not an immediate or inexpensive solution.
USACE recommends a deterrent measure consisting of an acoustic bubble curtain with strobe lights (ABS fish deterrent) near the Brandon Road Lock and Dam.
This combination of deterrents is intended to guide Asian carp into a geographically isolated location in order to allow partner agencies to conduct control and eradication efforts.
Several locations were considered and the Army Corps of Engineers recommends one ABS fish deterrent placed at the as a demonstration project at the Brandon Rock Lock and Dam.
The demonstration deterrent system will allow USACE to calibrate the ABS fish deterrent to the most effective settings for Asian carp because it will be located in an area where Asian carp are known to exist and where it has the potential to reduce the population of Asian carp challenging the electric dispersal barrier.
Once the efficacy of the ABS as a fish deterrent has been evaluated, installation of additional ABS measures may be considered. Immediate installation of ABS fish deterrents at all four locations at this time does not appear to be warranted in light of the expense associated with this demonstration project and the uncertainties about the presence of live Asian carp in the CAWs above the electric dispersal barrier.
The system will be used in conjunction with other measures such as intensified commercial fishing and implementation of more extensive monitoring and rapid response programs. The fish deterrent systems and the monitoring systems are designed to allow iterative adjustments to optimize system performance. This adaptive management strategy offers the best means currently available to rapidly and substantially reduce the risk of Asian carp establishing a self-sustaining population in the Great Lakes via the Illinois Waterway System.
This study is currently in development, further information will be posted as it becomes available. Please Note: Public comment period for Interim Report III ended June 15, 2010