Fisheries Special Report No. 23, 1998.
This is one of a series of river
assessments to be prepared by the Fisheries Division of
the Michigan Department of Natural Resources (MDNR) for
Michigan rivers. This report describes the
characteristics of the River Raisin and its biological
communities.River
assessments are prepared to provide a comprehensive
reference for citizens and agency personnel who desire
information about a particular fisheries resource. These
assessments will provide an approach to identifying
opportunities and solving problems related to aquatic
resources in watersheds. It is hoped that this river
assessment will increase public awareness of the River
Raisin and its challenges and serve to promote a sense of
public stewardship and advocacy for the resources of the
watershed. The ultimate goal is to increase public
involvement in the decision making process to benefit the
river and its resources.This document consists of four
parts: an introduction, a river assessment, management
options, and public comments and responses. The river
assessment is the nucleus of the report. The
characteristics of the River Raisin and its watershed are
described in twelve sections: geography, history, geology
and hydrology, channel morphology, soil and land use
patterns, biological communities, special jurisdictions,
recreational use, dams and barriers, water quality,
fishery management, and citizen involvement.The management options section of
the report identifies a variety of challenges and
opportunities. These management options are categorized
and presented following the organization of the main
sections of the river assessment. It must be stressed
that the options listed are not necessarily recommended
by MDNR, Fisheries Division. They are intended to provide
groundwork for public discussion and comment.The River Raisin and its
tributaries form a network draining approximately 1,070
square miles of southeastern Michigan and northwestern
Ohio. The basin contains portions of the following
Michigan counties: Hillsdale, Jackson, Washtenaw,
Lenawee, and Monroe. A small portion of Fulton County,
Ohio is also in the watershed. Major tributaries of the
River Raisin include the South Branch, Wolf Creek, Macon
Creek, Black Creek, and Saline River.For purposes of discussion, the
River Raisin mainstem is divided into three sections. The
first section is from the headwaters in the extreme
northwestern portion of the watershed downstream to
Tecumseh. The second is the low-gradient, meandering
mid-section of the mainstem from Tecumseh downstream to
Dundee. The final section is from Dundee downstream to
the mouth at Lake Erie.Streams in the upper portion of the
watershed above Tecumseh have moderately stable flows.
However, flow stability decreases in streams in the
middle and most downstream portions of the watershed
primarily because of less permeable soil type coupled
with intensive agricultural land use. Stream
channelization, removal of floodplains and wetland
retention areas, and installation of artificial surface
and tiled drainage systems to facilitate agriculture have
reduced flow stability throughout the watershed. Water
withdrawals for agricultural irrigation aggravate natural
low flow situations during droughts, particularly in the
upstream portion near Brooklyn, Manchester, and Clinton.
Water withdrawals for municipal use also reduce stream
flows. The communities of Adrian, Blissfield, Deerfield,
and Dundee rely on the River Raisin for public water
supply. Flooding is a recurring problem in the lower
watershed in Monroe and Frenchtown townships and the City
of Monroe. Much flooding is attributable to ice jams in
the lower river and periodic high levels of Lake Erie.The average gradient of the River
Raisin mainstem is 3.2 feet per mile. However, gradient
is not uniform throughout. The highest average gradient
(5.7 feet per mile) is from the headwaters to Highway
M-50 in Tecumseh. The lowest average gradient (1.3 feet
per mile) is in the mid-portion of the river between
Tecumseh and Dundee. The mainstem of the River Raisin is
mostly low-gradient channel, 92 miles (62 %) having
gradient less than three feet per mile. Fish and other
aquatic animals are typically most diverse and productive
in river gradient between 10 and 70 feet per mile. This
highly desirable gradient class is found in only 7.5
miles (5%) of the mainstem in the extreme headwaters of
the watershed and in localized areas near Brooklyn,
Manchester, and Tecumseh. Much of this high-gradient
habitat has been inundated by dams in Brooklyn,
Manchester (2 dams), and Tecumseh (3 dams). These dams
and their impoundments have eliminated and fragmented
some of the best fish habitat on the river.The channel of the mainstem has
been adversely altered over the years by agricultural
activities. Flow instability and resulting erosion have
caused the channel to be excessively narrow in the middle
portion where stream banks with high clay content are
resistant to erosion. Conversely, the channel is
excessively wide below the confluence of the mainstem and
Saline River, downstream from Dundee. The substrate from
this point downstream to the mouth at Lake Erie is
composed of gravel, cobble, rock, and limestone bedrock.
Therefore, during high flow, the less erosion-resistant
stream banks are eroded. Agricultural activities
including channelization and drainage have decreased the
hydraulic diversity of tributary streams throughout the
watershed. Intensive agricultural land use has caused
woody cover to be sparse in many portions of the mainstem
and major tributaries. Woody cover creates excellent fish
habitat and provides good substrate for production of
aquatic insects and other fish food organisms.Land use is the primary factor
causing decline of fisheries resources in stream
ecosystems. The River Raisin watershed has the highest
percentage of agricultural land use (92%) of any
watershed in Michigan. Intensive agricultural land use
coupled with fine particle soil types has degraded the
river system by decreasing flow stability, altering
natural channel morphology, and creating severe erosion
and sedimentation problems. Channelization, drainage of
wetlands, and installation of surface and tiled
artificial drainage courses to facilitate agriculture
have also decreased flow stability and altered
temperature regimes.Based on biological surveys
conducted during the past thirty years and early
twentieth century University of Michigan records, the
River Raisin watershed is known to have contained at
least ninety fish species. Although present fish species
diversity remains high, certain species are declining and
potamodromous fishes have been virtually eliminated by
the cooling water intake at the Detroit Edison Monroe
Power Plant near the mouth. A series of six low-head dams
in Monroe and Waterloo Dam at the western edge of the
city also create barriers to upstream migration of
potamodromous fish. Silt-tolerant fish species have
increased, whereas fishes requiring clean gravel
substrate or clear water with aquatic vegetation at some
point in their life cycles have declined. Dams have
inundated high-gradient areas with gravel, cobble, and
rock substrates. These high-gradient areas are of
critical importance to certain species as spawning
habitat and for the production of aquatic insects and
other macroinvertebrates that are important fish food
organisms. Agricultural activities have reduced flow
stability and increased sediment load in streams
throughout the watershed. Mussel species have declined
primarily as a result of increased sediment loading
resulting from agriculture and urban development.
Introduced pest species including zebra mussels, rusty
crayfish, Eurasian milfoil, curlyleaf pondweed, and
purple loosestrife have had negative effects on native
fishes and macroinvertebrates. Wetland drainage and
filling primarily to facilitate agriculture have
negatively affected populations of fish, amphibians, and
reptiles.The River Raisin watershed has
great potential for recreational use because of its
proximity to population centers in the watershed and in
the heavily populated surrounding area of southeastern
Michigan and northwestern Ohio. The mainstem is canoeable
from Brooklyn to the mouth, although logjams between
Adrian and Deerfield make canoe travel difficult in
localized areas. Bona fide access to the river is only
fair, and assured public access to impoundments is needed
at Sharon Hollow, Manchester, Clinton, and Tecumseh (Red
Millpond). Small access sites are needed on the mainstem
downstream of the Ford Dam in Manchester, upstream of the
Clinton Impoundment, downstream of Tecumseh, east of
Adrian, and in southern Palmyra Township. Public parcels
of property at Ida-Maybee Road and downstream of Dundee
should be developed to facilitate canoe access and shore
fishing. Very little land in the intensively agricultural
River Raisin watershed is in public ownership. The
acquisition of more public property would benefit
recreational users. Legislative adoption of a
recreational rather than commercial definition of
navigability would benefit canoeists.According to two independent
sources, there are about sixty dams in the River Raisin
watershed. Twenty-two of these dams, including the six
low-head dams in Monroe, are on the mainstem and 38 are
on tributaries. Dams fragment habitat of fish and other
aquatic organisms. Spawning runs of potamodromous and
river fish species are blocked by dams. Northern pike
populations have decreased particularly in southern
Michigan because the installation of lake-level control
structures (dams) on lake outlets has eliminated access
to pike spawning habitat. Dams disrupt normal downstream
drift of aquatic insects and other invertebrates,
sediment, and woody debris. Fish are killed outright or
injured passing over dams. None of the dams in the River
Raisin watershed has effective fish passage facilities.
Dams were generally constructed in areas of highest
stream gradient. This enables the dam builders to create
the highest possible drop (greatest potential energy)
while minimizing the amount of inundated land. These
high-gradient river areas are essential spawning habitats
for several fish species and highly productive areas for
aquatic insects and other fish food organisms. Dams also
alter the natural flow and temperature regimes of rivers.
Many of the impoundments in the River Raisin watershed
are shallow, sediment-laden, and choked with aquatic
vegetation. They provide poor quality habitat for sport
fish species and have only modest recreational value.The Detroit Edison Monroe Power
Plant at the mouth of the River Raisin presents a
formidable obstacle to upstream and downstream migration
of potamodromous fish. This power plant's cooling
water requirement of up to 3000 cfs greatly exceeds the
River Raisin annual mean flow of 741 cfs. Therefore,
during all but high flow periods, the entire flow of the
River Raisin is processed through the power plant as
cooling water. Besides the available River Raisin stream
flow, Lake Erie water is drawn upstream to the plant
through the river channel. This process essentially
reverses the flow of the river and forces it to
"flow" upstream. The processed cooling water is
then returned to Lake Erie through a separate outlet
channel to Plum Creek Bay that is out of the River Raisin
watershed. Impingement of adult and juvenile fish and
entrainment of larval fish and fish eggs at the power
plant are significant problems. Unless the cooling water
intake situation at the power plant is altered,
potamodromous fisheries management in the lower River
Raisin is impractical.Point source water pollution from
industrial and municipal sources in the watershed has
been dramatically abated over the past thirty years.
Pollution from point sources will continue to be reduced
in the future as municipal wastewater treatment plants
upgrade their facilities and technology and industrial
discharge permits are tightened.The greatest remaining factor that
degrades water quality in the watershed is nonpoint
source pollution resulting from agriculture. Recent
studies have shown conclusively that implementing best
management practices on farmland can significantly reduce
runoff, erosion, and delivery of sediment, nutrients, and
agricultural chemicals to watercourses.The lower River Raisin has been
identified by the International Joint Commission as one
of Michigan's fourteen Areas of Concern (AOC) due to
polychlorinated biphenyl (PCB) and heavy metal
contamination of fish and sediments. The AOC includes the
most downstream 2.6 mile portion of the river and the
immediate Lake Erie area extending one mile north and
south of the river mouth and one-half mile lakeward.
Problems that exist in the River Raisin AOC are heavy
metals (zinc, chromium, copper) and PCB contamination of
sediments and water column, sediment from nonpoint
agricultural sources outside the AOC, and a fish
consumption advisory concerning carp and white bass.Fishery management of the mainstem
and major tributaries has been neglected. Past municipal
and industrial point source pollution, excess turbidity
from intense agricultural land use, lack of assured
public access, and a very poor public image of the river
particularly from Tecumseh to Dundee have combined to
discourage fishery management. Enhancement and promotion
of angling opportunities on southern Michigan rivers are
one of few remaining frontiers available to fishery
managers.The greatest impediment to
beneficial change in the River Raisin watershed is the
poor public image of the river and its major tributaries.
This negative public image and perception of the river
must be improved to motivate people to take pride in the
river and advocate habitat protection and enhancement of
water quality and recreational opportunities. An improved
public image of the river would serve to foster an ethic
of public stewardship that would act to drive all other
beneficial changes. Direct involvement of local citizens
with the River Raisin and its watershed is the only way
to improve public image and erase negative perceptions.
- Dodge, Kenneth E. 1998. River Raisin Assessment. Michigan Department of Natural Resources, Fisheries Division, Special Report 23. Ann Arbor, Michigan.