The U.S. Army Corps of Engineers (USACE) operates and maintains the Upper Mississippi River 9-Foot Channel Navigation Project, and one method USACE uses to maintain the 9-foot channel is dredging river soils or “material.”

The purpose of the Pool 10 Dredged Material Management Plan (DMMP) is to prepare a coordinated, long-term plan for managing dredged material in Pool 10. This plan was initiated due to needs for dredged material management at upland placement sites, especially in the downstream reach of the pool.

Location

The Pool 10 DMMP study area is located between Lock and Dam 9 near Lynxville, Wisconsin, and Lock and Dam 10 at Guttenberg, Iowa, spanning nearly 33 river miles from 615.1 to 648.0. The study area includes several communities near the main navigation channel such as Prairie du Chien, Wisconsin, and Guttenberg, Iowa.

Description

There are nine historic dredge cuts in Pool 10. Of those nine, five are considered active, with three of those five requiring dredging on a nearly annual basis in the downstream end of the pool. Since 1981, the average amount of material dredged per year in Pool 10 is approximately 27,000 cubic yards; however, in the past decade, that amount has increased to nearly 40,000 cubic yards.

The DMMP is evaluating a list of potentially suitable sites to develop the federal standard or base plan for managing dredged material for a minimum of 20 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 Code of Federal Regulations 335.7).

Status

In fiscal year 2021, USACE began drafting the Tentatively Selected Plan (TSP) for the Pool 10 DMMP. USACE obtained feedback from affected stakeholders, including via a public meeting to inform local communities of the navigation mission, federal acquisition process, and USACE’s desire to identify willing sellers for the possibility of permanent upland placement of dredged material. USACE began identifying appropriate sites and drafting the report in 2023.

A draft report with the TSP alternatives, including innovative technologies such as bedload collector/sediment bypass systems, is on hold through fiscal year 2025 due to funding constraints. USACE will evaluate and consider all alternatives identified in the public comments for the final DMMP. Subsequent real estate acquisition is anticipated to begin upon report completion and will be phased over time, pending prioritization of parcels and availability of funds..