River Restoration

Rivers and streams, their channels and valleys, are a defining feature of Iowa’s landscape. They have formed and evolved over thousands of years, in response to the climate, soils, and geologic setting of their watersheds. Human modifications to the landscape, and to the rivers themselves, have altered these waterways contributing to problems including bank erosion, habitat loss, flooding, reduced water quality, and challenges to boater safety. River restorations are designed to overcome the effects of these alterations and improve the function and value of our waterways. Projects such as dam removals and mitigations, bank stabilizations, and installation of riparian buffers have been shown to improve the health of aquatic life and increase fish populations, benefit wildlife, reduce flood damage, protect agricultural land, increase recreational opportunities and make them safer and more enjoyable, and bring economic benefits to nearby communities.

DNR is currently working with its partners to coordinate and improve river restoration efforts. To date, the DNR has developed a strategy, participated in development of the Iowa Stream Mitigation Method, developed best management practices for a river restoration toolbox along with supplemental tools, and coordinated discussions regarding a potential in-lieu fee program.

Iowa’s River Toolbox is available to provide a consistent way to assess streams and address instabilities that cause erosion and infrastructure damage. The assessment provides a direct path to understanding the drivers of instability along with a menu of possible solutions.

Iowa's River Restoration Toolbox

A significant number of DNR programs relate to rivers, river corridors, watersheds, and water quality. A strategy to align and coordinate these programs in support of river restoration grew from a week-long planning session in 2015, which included partners such as IDALS, NRCS, Iowa Natural Heritage Foundation, and County Conservation Boards.

River Restoration – Aligning DNR River Programs
River Restoration – Aligning DNR River Programs, Fact Sheet
River Restoration - 2017 Progress Report

The federal Clean Water Act requires mitigation when development activities are unable to avoid impacting jurisdictional streams and wetlands. On June 30, 2017, the US Army Corps of Engineers (USACE) adopted the Iowa Stream Mitigation Method (ISMM) for evaluating impacts to streams and determining whether proposed mitigations are sufficient to offset proposed impacts. Descriptions and tools can be found here:

• US Army Corps of Engineers - Stream Mitigation

Several resources are available now, or in development, to help consultants, public land managers, and individual landowners who want to restore functions of rivers and according to their goals. Check back as new items are added.

Iowa Riverside Plant Selection
Appropriate native plantings are a key to successful river restoration projects. This tool is organized by various design scenarios for ease of use.
Iowa Riverside Plant Selection

Cross Section Tool
LiDAR-based cross sections can easily be drawn across stream valleys to provide crucial information for stream projects involving restoration, permitting, and mitigation. Stationed data tables can be exported to use in a variety of software applications for analysis. The Iowa Elevation Tool is particularly useful for identifying low floodplain elevations, valley characteristics, and bank full width in a stream segment. Note that LiDAR data does not include points below the water surface.

Dam Mitigation
Dam mitigation restores navigation, safety, and fish movement functions of rivers. Restoration techniques outlined in the 2010 dam mitigation plan describes various approaches (such as rapids construction or dam removal) to mitigate problems associated with dams, and ways to leave the dam site in a restored condition as a project is built. Program resources are also available to assist dam owners with decision making, technical resources, and funding to complete projects.

BioNet
A key to understanding effective habitat restoration goals is to understand which fish and macroinvertebrate species have been sampled in a given stream, how the degraded segment is deficient, and which associated habitats exist nearby. Bionet is a database to assist with determining aquatic species and habitat presence organized by map and topic, along with indices comparing biological integrity to regional reference reaches with documented diversity.

• https://programs.iowadnr.gov/bionet/

Michael Steuck, 563-927-3276 and Nate Hoogeveen, 515-725-2991