Chocolay River Restoration (Thalwegzation) Demonstration Project
Marquette County Soil and Water Conservation District
Basin Program Funds:
The Michigan Department of Natural Resources estimates that an excess of 80%
of the streams in the Chocolay River watershed are severely impacted due to
erosion and sedimentation. Erosion and sedimentation have had two major impacts
on the Chocolay River watershed. First, they have choked some sections of the
river until what was once a narrow, fast-flowing and relatively deep channel
(thalweg) has become silted in. Second, this excessive bedload limits the ability
of invertebrates and fish to reproduce in the river. Beneficial aquatic vegetation
is also severely impacted by sediment deposition The ecological degradation
in turn results in economic impacts such as reduced sport fishing revenue and,
due to the loss of navigable stream channel, fewer recreational activities.
The Chocolay River Restoration (Thalwegzation) Demonstration Project is an innovative
two-phase stream restoration and stabilization project. The first phase of the
project, involving numerous cooperating agencies and participation by local
civic organizations, youth groups, and the general public, will undertake ten
hands-on stream restoration and stabilization projects covering over 2,500 feet.
Phase two will be an intensive information and education component targeting
local landowners, businesses and public agencies.
The Chocolay River is a tributary to Lake Superior and drains
a very diverse 147 square-mile watershed adjacent to the city of Marquette (pop.
21,977). The Chocolay River watershed is experiencing excessive erosion, sedimentation,
and nonpoint source pollution due to increased residential, recreational, and
business development, as well as significant erosion impacts from logging, large-scale
road construction projects, and highway maintenance practices. Big Creek, a
tributary to the Chocolay River, has been selected for the demonstration project
because of its manageable size and because its problem sites, though limited
in number, are significant. The proposed stream restoration work will enable
the creek to flush out accumulated sand and sediment at the same time a natural
stream channel (or thalweg) is restored.
Prior to beginning the demonstration project on Big Creek, the Chocolay River
Project remediated a number of severe erosion sites upstream. Project team members
stabilized critical areas and replaced a substandard stream crossing and culvert
These efforts resulted in savings of 15-25 tons of soil annually.
The field work on the Big Creek demonstration project began in
April, 1955 and was scheduled to be completed in September 1995. Articles in
the local newspaper (30,000 circulation) and the project newsletter (2,000 circulation)
have informed the general public and all riparian landowners of the project.
Volunteer interest in the project has been high. College students (10 individuals),
youth groups (8 individuals) and other local citizens (5) make up the core group
of volunteers. As of mid-August, over 5,000 linear feet of stream habitat had
been restored, well in excess of the originally proposed 2,500 feet.
Prior to this project, the MDNR documented that Big Creek's stream
substrate was 100% embedded by buried sediment. Since the project began, monitoring
shows that treated areas are showing 30-50% exposure to the original gravel
stream bed and spawning areas. In other words, 30-50% of the sediment load has
been scoured out and flushed downstream due to the implemented restoration practices.
Stream habitat conditions have improved dramatically.
The project has leveraged approximately $17,000, including: approximately
:$12,000 in equivalent volunteer hours (based on $10/hour); $1,000 provided
by the Marquette Conservation District for materials and supplies; and a $4,000
MDNR fisheries grant, based on the project's success, to continue the project
after the Big Creek phase.
As a result of its success, this project has been receiving both
national and international attention. The Natural Resources Conservation Service
used the Big Creek demonstration project in a video and in a stream restoration
training manual scheduled for national distribution. Also, the International
Joint Commission has included a write up on the project in its newsletter and
on its Internet site.