The purpose of the Dredged Material Management Plan (DMMP) is to prepare a coordinated long-term plan for managing dredged material in Pool 2. This plan was initiated due increases in dredging volumes throughout Pool 2. Furthermore, three temporary dredged material placement sites need to be excavated in Lower Pool 2.
The Pool 2 DMMP study area is located between Lock and Dam 2 near Hastings, Minnesota and extends upstream to Lock and Dam 1, from river miles 815.2 to 847.7, respectively. The study area includes Upper Pool 2, which is situated in the urban area of Minneapolis and St. Paul.
The U.S. Army Corps of Engineers operates and maintains the Upper Mississippi River 9-Foot Channel Navigation Project, and one method the Corps uses to keep the channel the authorized width and depth is dredging river soils or “material.”
Pool 2 has been experiencing higher flows due to rainfall. As a result of more sediment, Pool 2 now requires additional dredging. Between 1981 and 2014, the average amount of material dredged per year in Pool 2 was approximately 107,000 cubic yards. The Corps’ September 2016 sediment assessment predicted future dredging requirements throughout Pool 2 to increase substantially, to approximately 169,000 cubic yards per year. Therefore, the 40-year target capacity for the Pool 2 DMMP is approximately 6.8 million cubic yards.
The DMMP is evaluating a list of potentially suitable sites to develop the Federal Standard or Base Plan for managing dredged material over the next 40 years. The Federal Standard is defined as “the dredged material disposal alternative or alternatives identified by the Corps which represent the least costly alternatives consistent with sound engineering practices and meeting the environmental standards established by the [Clean Water Act’s] 404(b)(1) evaluation process…” (33 CFR 335.7).
In 2019 planning continued in an effort to identify the Tentatively Selected Plan (TSP) for the Pool 2 DMMP that would meet the Federal Standard.
The draft report with the TSP was released to the public for review for greater than 30 days in November 2019. The Corps evaluated and considered all public comments for the final DMMP.
In summer 2020, the Corps will finalize the Pool 2 DMMP and start the federal acquisition process for the plan preferred permanent upland placement site of dredge material at Lower Grey Cloud Island.
Congress authorized the Upper Mississippi River 9-Foot Channel Navigation Project via the River and Harbor Act of 1930.
Expended to Date $1,117,026