Join us! TOWN HALL INFO Meeting
Sept. 11 – Niobrara Fire Hall Meeting Room
5:30 pm Open House; 6 pm USACE Presentation
(NEWS RELEASE) – For nearly one week in September, the sediment load reaching the Lewis and Clark Lake delta will be reduced thanks to a 12-foot bedload collector operating on the bottom of the Niobrara River.
Even though this short-term pilot project marks a tiny fraction of the annual sediment load, it signals a milestone for efforts focused on extending and sustaining the lifespan of Lewis and Clark Lake created by Gavins Point Dam on the Missouri River. The Missouri Sedimentation Action Coalition (MSAC) and its supporters eagerly anticipate seeing how this technology performs and its potential success for a full scale, on-going method to lessen the load of sediment entering the system. Reducing the amount of sediment entering the delta would extend the reservoir’s lifespan and associated benefits.
The one-week bedload collector pilot project, running September 9-13, is made possible by the US Army Corps of Engineers (USACE) Regional Sediment Management Program. USACE-Omaha District in collaboration with the Corps’ Engineer Research and Development Center (ERDC) of Vicksburg, Mississippi, are coordinating the installation and data collection. MSAC is facilitating several avenues for public outreach.
The public can learn more Wednesday, September 11th during an open house at 5:30 pm and presentation beginning at 6 pm with USACE Pilot Project staff, Paul Boyd, Omaha District hydraulic engineer and Chuck Theiling, ERDC-research aquatic ecologist. It will be held in the Niobrara Fire Hall meeting room. The pilot project site location just north of Highway 12, west of the community of Niobrara is not easily accessible to the public. Ample, established parking is not available. The uneven terrain is currently very vegetated and approximately one-quarter of one mile to reach the collector installation site at the Niobrara River. MSAC is working to coordinate a Field Day to transport a small number of stakeholders to the site.
The public can get a bird’s eye view across the Niobrara River at the Niobrara State Park. During Pilot Project week, an observation area in the State Park is available directly west of the project site, on the opposite bank of the Niobrara River. MSAC has reserved camping spot #25 in the RV campground for the public to view the collector at work. A park access pass is needed to gain entry to the Niobrara State Park and campground loop. Daily passes are available. MSAC staff plan to be on hand at the observation area Thursday (Sept. 12th) from 10 am to 5 pm. Bring your binoculars. Watch for more details.
USACE researchers estimate that historically the Niobrara River contributes as much as 60 percent of the sediment accumulating in the Lewis and Clark Lake delta. USACE describes the delivery as “chronic” due to the nearly unlimited sediment supply and base flow driven by springs through the basin. The sediment delivery is slow and continuous. Delivery increases during flood events. As outlined in the USACE proposal, “This condition makes it an excellent candidate for this type of passive collection system that can operate continuously.”
Once the pilot tests are complete, a USACE-authored report will summarize the work and attempt to examine how increasing the scale of collection throughout the watershed could benefit Lewis and Clark Lake and the delta area.
Background …
US Army Corps of Engineers – Omaha District has been partnering with the Missouri Sedimentation Action Coalition (MSAC) on a multi-phase study to develop a Sediment Management Plan (SMP) for the Lewis and Clark Lake region, behind Gavins Point Dam along with the areas upstream and downstream of the reservoir. As a result of an SME-led workshop in June 2021, bedload collection on tributaries was one of four management methods identified for further examination. In collaboration with the Corps’ Engineer Research and Development Center (ERDC) Environmental Lab, the project will place a 12-foot length bedload collector in the Niobrara River for five days late summer 2024 and analyze the efficiency of collection in the high-bedload conditions prevalent on the Niobrara River.
MSAC is hosting a field day for stakeholders, media and elected officials. Pilot project results will be used to develop scaled estimates of the effectiveness of the method and its applicability in similar conditions across the USACE reservoir portfolio.
This effort is made possible by the Corps’ Regional Sediment Management (RSM) Program.
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The Niobrara River contributes between 50 and 60 percent of the total sediment load into the Missouri River reach that makes up the Lewis and Clark Lake delta. This condition is termed “chronic” due to the nearly unlimited sediment supply and slow and continuous delivery, which is heightened during flood events. “This condition makes it an excellent candidate for this type of passive collection system that can operate continuously,” was stated in the USACE proposal.
A future full-scale project could support sediment management efforts in the Lewis and Clark Lake region required to reach a sediment balance. In the near term an operational bedload collector could assist in reducing sediment load, and begin the process of extending the reservoir’s lifespan and associated benefits.
ERDC has been examining collectors over the past 20 years. Most of the previous work was with small collectors, measuring 2 to 4 feet, or in conjunction with existing installations of up to 30 feet.
MSAC plans to build upon this effort by researching beneficial uses for harvested sediment. This has been one of the sticking points for bolstering the bedload collector idea, and in fact, all sediment extraction proposals. A criticism has been merely harvesting the sediment and placing it on shore – only moves the problem to a new location and that storage of such a large amounts will be impractical. Demonstrating the effectiveness of a bedload collector is a big step in finding markets for the material.
Watch for more details about this effort and availability of the collected sediment at the conclusion of the pilot project. MSAC aims to keep the public informed throughout the Pilot Project week, planned for September 2024 (tentative), along with how this technology may fit into a future multi-prong approach to manage sediment in the Lewis and Clark Lake region, lengthen the reservoir’s lifespan and reduce local impacts. Please note that this project had been slated for August and now it is expected to be scheduled later in 2024.
Click this link to provide us with your contact information if you want to be updated on details of the Late Summer 2024 Pilot Project (Sept 9-13). Or select the button below.
From MSAC Reports – Information was taken from USACE’s Niobrara River Sediment Bedload Collector Pilot Project RSM proposal