4 minute read
Ohio River Bonanza Bar
Portsmouth, Ohio, United States
Using dredged material beneficially to create ecological habitats and restore the historical footprint. The Bonanza Bar is an ephemeral island near the City of Portsmouth, seated between the banks of the States of Ohio and Kentucky in the Ohio River. Historically, the island has been used for dredged material placement dating back to the early 1980s. In the early 2000s, the U.S. Army Corps of Engineers (USACE)–Huntington District received approval from the Kentucky Division of Water (DOW) to hydraulically “stack” dredged material near the bankline, with the specific intent to leave space sufficient for sustaining back-channel habitat in the slack waters created by the bar. From an agency partnering meeting in 2011, the USACE Huntington District began to develop the island as a beneficial use site by incorporating the back channel between the bar and the Kentucky bankline. The ephemeral island is currently constructed entirely of dredged material and has been restored to mimic its footprint in the river channel documented more than 50 years ago. As successful placements have occurred over the past decade, the creation of the Bonanza Bar has subsequently allowed for more efficient dredged material placement and reduced timing, frequency, and cost of dredging in the adjacent navigation channel while providing valuable ecological habitat and recreational opportunities.
Article Cover: Bonanza Bar island habitat. Ecological benefits observed at the project site include increased mussel populations, the presence of migratory birds, and creation of riverine backchannel habitat. (Photo by USACE Huntington District)
Producing Efficiencies
Since 2016, the number and cost of dredge requirements near the Bonanza Bar reach have declined. This decrease in dredging needs has coincided with the Bonanza Bar island creation. Hypothetically, the islands are concentrating the flow to maintain a more sustainable federal channel. The cross-sectional area of the river had changed due to the deposition of dredged material. The current trend in the Bonanza Bar project area is that there is less shoaling in the region, leading to the decline of dredging demands over the past several years.
Using Natural Processes
The USACE Huntington District is currently interested in stabilizing and growing the bar to serve as additional constriction on the navigation channel (reducing or potentially removing the need for repetitive maintenance dredging) and stabilizing downstream and adjacent ecological resources (i.e., mussel bed habitat). Therefore, placement regions have been informed by historical bar locations, and the current Bonanza Bar footprint, created with dredge placement, mimics the location of the natural bar formation as documented in historical navigation charts. The dredge placement is unconfined, and the energy of the river is used to distribute the sediment and shape the bar.
Broadening Benefits
The development of the ephemeral Bonanza Bar has created a riverine back-channel habitat. Migratory birds have been observed on the island, and mussel populations have increased with beds present along the downstream bankline and side channels adjacent to the islands. USACE Huntington District has sponsored nine mussel surveys along the left descending bank at the Bonanza Bar, which shows mussel habitat existing along the Kentucky shoreline there, indicating a thriving population. Located outside of a small town and with a public access boat ramp close by, the island is also regularly used as a popular boating spot by residents and tourists alike.
Promoting Collaboration
A change in philosophy allowed the USACE Huntington District to adapt to a more sustainable approach to dredged material management by using a stakeholderdriven approach to guide its dredge program. The Huntington District collaborated closely with the U.S. Fish and Wildlife Service, the Kentucky Department of Natural Resources, and the DOW on the approach to redirect placement of dredged material away from the bank (to incorporate side channel habitats) and to obtain the related water quality certification permit. At annual stakeholder meetings, the district’s proactive approach transformed a contentious atmosphere to one of collaboration.
