Blackhawk Bottoms, Pool 19, Iowa – CAP Section 206

Rock Island District
Published Oct. 1, 2021
An aerial of the Blackhawk Bottoms area located in south eastern Iowa, Des Moines County, near the confluence of the Skunk and Mississippi Rivers.

An aerial of the Blackhawk Bottoms area located in south eastern Iowa, Des Moines County, near the confluence of the Skunk and Mississippi Rivers.

Location

Blackhawk Bottoms is located in south eastern Iowa, Des Moines County, near the confluence of the Skunk and Mississippi Rivers. The area lies approximately 6 miles south of Burlington, Iowa at Mississippi River river mile 398.0 to 399. The Project area is roughly 163-acres and is located in the northwest corner of the Iowa Department of Natural Resources Blackhawk Bottoms Wildlife Management Area.

Description

This project provides the opportunity to restore the historic fall flood pulse within Pool 19 of the Mississippi River at Blackhawk Bottoms. Restoration of the historic fall flood pulse will support MSU habitat, which provides an opportunity for waterfowl and other wildlife to have quality food and shelter source through the year especially during the fall months.

The goals of the project are to restore MSU habitat and provide a fall season food source and habitat for local wildlife as well as birds migrating along the Mississippi River Flyway. The objectives identified to meet these goals are (1) Increase the depth and period of time the water is impounded during the fall season; (2) Increase the areal coverage of seasonally flooded wetlands that act as a source of food for migratory waterfowl and other local wildlife; and (3) Decrease the areal coverage of non-wetland species in the floodplain.

Project Features:

  • Earth berm/dike
  • Water control structures
  • Spillway

This project provides the opportunity to restore the historic fall flood pulse within Pool 19. Restoration of the historic fall floods pulse will support MSU habitat, which provides an opportunity for waterfowl and other wildlife to have a high-quality food and shelter source throughout the year but especially during the fall months.

The Iowa Department of Natural Resources is the sponsor for this project.

Background
Historically, the river floodplain included interconnected habitats such as forests, backwaters, deep-water wetlands, wet meadow prairies, and mesic prairies. Some species depend on the natural ability of a river to flood its banks and reach into its floodplain. Prior to the construction of L&D 19, the backwater areas near the river would see greater water depths in the spring and fall due to increased precipitation. Spring floods would inundate backwater areas and seed them with moist soil plants. As the precipitation increase in the fall, the river would rise again to create a valuable food resource at the time that coincides with the fall waterfowl migration to the south. However, under the current lock and dam regulations to maintain the 9-foot channel, the river never goes to a low stage in summer or experience significant fall flooding.

Status

Environmental Assessment was approved in August 2012 and the Project Partnership Agreement was executed in September of 2013. Contract was awarded September of 2014 and completed in November 2016. The Operation and Maintenance Manual was finalized in August 2017. The first monitoring report was completed in September 2019. The next monitoring report is due in 2021.

Authority

CA - Continuing Authorities – Section 206

Section 206 of the Water Resources Development Act, as amended (Environmental Protection and Restoration, Aquatic Ecosystem Restoration)

Additional Information

Summarized Project Costs

Estimated Federal Cost

$ 1,424,846

Estimated Non-Federal Cost

$ 509,833

Estimated Total Project Cost

$ 2,193,807

Allocations Prior to FY 2022

$ 1,424,846

FY 2021 Allocation

$ 0

FY 2022 Allocation

$ 0

FY 2022 President’s Budget

N/A

FY 2022 Total Capability

N/A

 

Major Work Item Prior Fiscal Year
FY 2021: Sponsor continued their adaptive management and monitoring activities for in-kind contributions.

Major Work Item Current Year
FY 2022: Sponsor will continue their adaptive management and monitoring activities for in-kind contributions.